What is new & noteworthy in Hono?

2.6.0

New Features

The protocol adapters now have experimental support for doing OCSP based client certificate revocation checks.

Fixes & Enhancements

The Command Router code has been split up into a base module and an Infinispan based implementation. This is in preparation of a Redis based implementation which is to be added in one of the upcoming minor versions.
Updated to latest Quarkus LTS version (3.8).
Updated to jjwt 0.12.5 which allowed us to replace a lot of manually crafted code for creating a JWK Set based on vert.x JWK with generic jjwt code.
Updated CoAP adapter to use Eclipse Californium 3.11.0.
Also push JDBC Registry native executable image to Docker Hub.

Deprecations

According to the MongoDB Software Lifecycle Schedule support for MongoDB 5.0 will end Oct 2024. Until that date the MongoDB based Device Registry will be tested with MongoDB 5.0, 6.0 and 7.0 in the CI workflows. However, support for MongoDB 5.0 in Hono has been deprecated and will be removed in a future version altogether. Users are encouraged to migrate to MongoDB 6.0 or later.

2.5.1

Fixes & Enhancements

Updated Quarkus to 3.2.12 which includes fixes for
Also push JDBC Registry native executable image to Docker Hub.

2.5.0

New Features

A more generic format for storing the OpenTelemetry trace context information in an AMQP 1.0 message can now be configured, writing the corresponding properties in the message application properties. This is for example relevant when using AMQP 1.0 messaging in connection with Eclipse Ditto, resulting in combined traces of Hono and Ditto. Please refer to the ${prefix}.useLegacyTraceContextFormat connection property documentation in the Hono Client Configuration Guide for additional information.
The JDBC based Device Registry implementation now has limited support for filter criteria when searching devices. Please refer to the Device Registry User Guide for details.
The Device Registry Management API’s search Devices operation now supports restricting the result set to gateway or edge devices only using the newly added isGateway query parameter.

Fixes & Enhancements

When running in a Kubernetes cluster with nodes using cgroups v2, the hono.command_internal.* Kafka topics were not being cleaned up. This has been fixed. Note that the solution requires the Hono protocol adapter pods to have a service account with an assigned RBAC role that allows to perform get on the pods resource.
When using Pub/Sub messaging, there were potentially issues concerning the AMQP connection between protocol adapter and command router, leading for example to timeouts when MQTT devices subscribed/unsubscribed to the command topic. This has been fixed.
The integration tests now use Apache Kafka 3.5.0 in Raft mode which no longer requires running a separate Apache Zookeeper instance and thus simplifies test setup and configuration.
The command line client was still trying to connect to the insecure ports of the Sandbox. This has been changed so that the client now uses the TLS endpoints and requires the user to specify a trust store for validating the server certificate.
All components now use Quarkus 3.2.9.Final.
The CoAP adapter now uses Californium 3.10.0.

Deprecations

According to the MongoDB Software Lifecycle Schedule support for MongoDB 4.4 will end Feb 2024. Until that date the MongoDB based Device Registry will be tested with MongoDB 4.4, 5.0, 6.0 and 7.0 in the CI workflows. However, support for MongoDB 4.4 in Hono has been deprecated and will be removed in a future version altogether. Users are encouraged to migrate to MongoDB 6.0 or later.

2.4.1

Fixes & Enhancements

A device connected to the MQTT adapter would not get disconnected when sending a message after the device’s credentials had already expired. This has been fixed.
When running in a Kubernetes cluster with nodes using cgroups v2, the ‘hono.command_internal.*’ Kafka topics were not being cleaned up. This has been fixed. Note that the solution requires the Hono protocol adapter pods to have a service account with an assigned RBAC role that allows to perform “get” on the “pods” resource.
When using Pub/Sub messaging, there were potentially issues concerning the AMQP connection between protocol adapter and command router, leading for example to timeouts when MQTT devices subscribed/unsubscribed to the command topic. This has been fixed.
The command line client was still trying to connect to the insecure ports of the Sandbox. This has been changed so that the client now uses the TLS endpoints and requires the user to specify a trust store for validating the server certificate.

2.4.0

New features

Hono now supports using Google Pub/Sub as the messaging infrastructure. The Admin Guide and the API documentation have been amended with corresponding information on how to configure Hono and applications for using Pub/Sub.
Hono’s MQTT and HTTP adapters now support using JSON Web Tokens (JWT) for authentication. In particular, the adapters allow devices that have been connected to Google’s IoT Core endpoints to connect to Hono instead. The User Guides have been amended with corresponding information regarding configuration and usage.
The CoAP adapter now allows clients to retrieve the CoAP adapter’s current time by means of including a query parameter and/or request option.
The HTTP protocol adapter now supports authenticating devices using the JWT based authentication scheme employed by Google IoT Core.
The command router now has experimental support for routing commands received via Google Pub/Sub to connected devices.
The authentication identifier being created for devices that are using client certificate based auto-provising can now be specified as a pattern based on fields from the certificate’s subject DN.

Fixes & Enhancements

The JDBC based device registry now supports searching for tenants and devices including paging. However, sorting is not implemented (yet) and the number of filter predicates is (currently) limited to one.
The MQTT adapter failed to close a connection with a client after the JWT used by the client for authentication had expired. This has been fixed.
Hono could not be built using Maven 3.9.0 and newer. This has been fixed.

2.3.2

Fixes & Enhancements

A device connected to the MQTT adapter would not get disconnected when sending a message after the device’s credentials had already expired. This has been fixed.
When running in a Kubernetes cluster with nodes using cgroups v2, the ‘hono.command_internal.*’ Kafka topics were not being cleaned up. This has been fixed. Note that the solution requires the Hono protocol adapter pods to have a service account with an assigned RBAC role that allows to perform “get” on the “pods” resource.
The command line client was still trying to connect to the insecure ports of the Sandbox. This has been changed so that the client now uses the TLS endpoints and requires the user to specify a trust store for validating the server certificate.

2.3.1

Fixes & Enhancements

Using Maven 3.9.x for building Hono was not possible and resulted in an error. This has been fixed.
The Device Registry User Guide has been amended with information on how to configure the trust anchor of a tenant using a PEM file.
The demo keys and certificates that come with Hono for testing purposes had expired and have been recreated.

2.3.0

New features

Hono services and adapters could be started locally (not in containers) for development/test purposes.
The MQTT adapter now has experimental support for authenticating devices using the JWT based authentication scheme employed by Google IoT Core.
The protocol adapters now have experimental support for using Google Pub/Sub as the messaging infrastructure. Support is currently limited to publishing downstream events and telemetry messages to Pub/Sub.
The JDBC based registry now supports the Device Registry Management API’s search Tenants and search Devices operations. However, sorting and filtering is not yet implemented.

Fixes & Enhancements

The MQTT adapter did forward command messages for devices behind a gateway when the gateway subscription was targeting the gateway itself with topic name command//[<gateway-id>]/req/#. This has been fixed. For a subscription with such a topic name, only commands for the gateway itself are forwarded, not commands for devices, that the gateway acts on behalf of.
The LoRaWAN adapter now transforms all devEUIs hex encoded and upper case. All LoRaWAN devices should therefore be registered upper case and hex encoded.

2.2.0

New features

All Hono components now support reading ECC based keys from PEM files that contain the Base64 encoded DER-encoding of an ECPrivateKey as described in RFC 5915, Section 4.
The build process now supports creating container images for the arm64 platform. Please refer to the Developer Guide for details.
The LoraWAN protocol adapter has been extended with support for Chirpstack V4 provider.
Hono components now support producing JSON formatted log messages. Please refer to the Admin Guide for details.
Hono components can now be configured to use the OTEL Jaeger Remote Sampler extension which allows the sampling strategy to be retrieved from a Jaeger back-end dynamically during runtime. Please refer to the Admin Guide for details.

Fixes & Enhancements

Documentation for versions up to 1.11 is removed as outdated.
Optimized handling of MQTT and AMQP protocol adapter shutdown. The purpose is removal of redundant operations for devices which maintain a permanent connection during the restarting of adapter instances. This prevents delays and possible errors due the higher rate of invocations of the unregister Command Consumer operation on the Command Router service. When shutting down, the adapters no longer explicitly unregister Command Consumers and no longer send disconnectedTtdEvents. Instead, the Command Router now sends the connectedTtdEvent and disconnectedTtdEvent on behalf of the protocol adapters. The Command Router now also sends a disconnectedTtdEvent when a command is received that is targeted at a device that got disconnected (and didn’t reconnect) when a protocol adapter was shut down. This happens only once - during the processing of the first command. The Command Router configuration now also requires hono.messaging configuration if AMQP 1.0 based messaging infrastructure is being used.
The Mongo DB based device registry is now continuously tested to work with Mongo DB 5.0.

2.1.0

New features

The tracing configuration has been extended to now also support a rate-limiting sampler. See the Monitoring & Tracing guide for details.
Add new metric for tracking the total number of Tenants in Hono.
The Auth server component now provides an HTTP endpoint for retrieving the keys that applications should use for validating the signature of tokens issued by the Auth server. The keys are being transferred by means of a JSON Web Key set as defined by RFC 7517. The Device Registry and Command Router components will use this endpoint to periodically download the keys if no key material has been configured explicitly.
The handling of messages that have no payload and/or no content type has been harmonized across the protocol adapters. Adapters now uniformly accept messages from devices that have no payload if the device explicitly sets a non-empty content type on the message. Messages with a non-empty payload can be uploaded without specifying a content type. In the messages being forwarded to downstream consumers, the adapters will either use the devices’s default content type, if defined, or otherwise fall back to application/octet-stream in such cases.
A Linux x86_64 executable of the command line client has been added to the downloads page.

Fixes & Enhancements

The CoAP adapter did not properly consider the reduced minimum RAM requirements for starting up when running as a native executable on a SubstrateVM. This could have resulted in the adapter not starting up at all, if configured with less than ~150MB of RAM. This has been fixed.
The HTTP protocol adapter and Device Registry now support a configuration property for explicitly setting a request’s idle timeout. The timeout is configured with the property idleTimeout. This determines if a request will time out and be closed if no data is received or sent within the idle timeout period. The idle timeout is in seconds. A zero value means no timeout is used.
The MQTT adapter skipped command or error (the first one) subscription if both were requested for the same device. This has been fixed.
On startup, Hono components could get into a state that caused certain Kafka client metrics to not get reported. This has been fixed.
Default messaging type changed to Kafka. Changed related documentation pages.
The native executable based Lora adapter container image failed to forward Lora meta information in messages being sent downstream. This has been fixed.
The Command Router component might not have reached the ready state in case the Kafka broker got restarted during Command Router startup. This has been fixed.
The mechanism used by the Command Router component to determine the state of protocol adapter instances has been improved.
The CoAP adapter returned a 500 error code for PUT requests without a device identifier in the URI path. This has been fixed, now returning a response with a 404 error code instead.
The command line client no longer throws an NPE when trying to upload an empty message without a content type to the AMQP adapter.

2.0.2

Fixes & Enhancements

The default value for the HTTP protocol adapter hono.http.idleTimeout configuration property has been increased from 60 to 75 seconds. This means HTTP requests with a hono-ttd value of 60 seconds (which is the tenant configuration max-ttd default) will not cause the idle timeout to be reached.
The mechanism used by the Command Router component to determine the state of protocol adapter instances has been improved.
The CoAP adapter returned a 500 error code for PUT requests without a device identifier in the URI path. This has been fixed, now returning a response with a 404 error code instead.

2.0.1

Fixes & Enhancements

The CoAP adapter did not properly consider the reduced minimum RAM requirements for starting up when running as a native executable on a SubstrateVM. This could have resulted in the adapter not starting up at all, if configured with less than ~150MB of RAM. This has been fixed.
The HTTP protocol adapter and Device Registry now support a configuration property for explicitly setting the idle timeout. The timeout is configured with the property idleTimeout. This determines if a connection will timeout and be closed if no data is received or sent within the idle timeout period. The idle timeout is in seconds. A zero value means no timeout is used.
The MQTT adapter skipped command or error (the first one) subscription if both are requested for the same device. This has been fixed.
On startup, Hono components could get into a state that caused certain Kafka client metrics to not get reported. This has been fixed.
The native executable based Lora adapter container image failed to forward Lora meta information in messages being sent downstream. This has been fixed.
Default messaging type changed to Kafka. Changed related documentation pages.
The Command Router component possibly did not reach the “ready” state in case the Kafka broker got restarted during Command Router startup. This has been fixed.
The CoAP protocol adapter now uses Eclipse Californium 3.6.0.
Upgraded to JJWT 0.11.5 which contains additional security guards against an ECDSA bug in Java SE versions 15-15.0.6, 17-17.0.2, and 18 (CVE-2022-21449). Note: if your application does not use these JVM versions, you are not exposed to the JVM vulnerability. The CVE is not a bug within JJWT itself - it is a bug within the above listed JVM versions, and the JJWT 0.11.5 release adds additional precautions within JJWT in case an application team is not able to upgrade their JVM in a timely manner.
The Auth server failed to create a token when configured with an ECC based private key that does not use the P-256 curve. This has been fixed.

2.0.0

New features

The HTTP protocol adapter now allows authenticated gateway devices to omit the tenant ID from the URI of requests used to upload telemetry, event or command response messages.
The CoAP protocol adapter now allows authenticated gateway devices to omit the tenant ID from the URI of requests used to upload telemetry, event or command response messages.
The AMQP protocol adapter now allows authenticated gateway devices to omit the tenant ID from the address of messages used to upload telemetry or event messages.
The MQTT protocol adapter now allows authenticated gateway devices to omit the tenant ID from the topic of messages used to upload telemetry or event messages.
The CoAP adapter now exposes its resources using short endpoint name alternatives to the existing resources. Using the short endpoint names, devices can save a few bytes per request.
The protocol adapters now support a configuration property for explicitly setting the percentage of the heap memory not to be used for maintaining device connections. This can be used to tune the adapter’s memory utilization with regard to the overall amount of memory available to the JVM and the characteristics of the garbage collector being used.

Fixes & Enhancements

The Quarkus variant of the MongoDB based device registry failed to start up if the hono.mongodb.dbName property was not set. However, the DB name should not be required if a connection string is set using the hono.mongodb.connectionString property. This has been fixed.
When a tenant or device gets disabled or deleted, any open AMQP or MQTT connections from clients having authenticated themselves as belonging to that tenant or device are getting closed now.
Using OpenSSL with the Quarkus based variant of Hono components did not work as described in the Secure Communication guide. This has been fixed.
The connection pool configuration for the HotRod client in the Quarkus variant of the Command Router component didn’t support using property names in camel-case. This has been fixed.
HonoConnectionImpl instances failed to release/close the underlying TCP/TLS connection when its disconnect or shutdown method had been invoked. This has been fixed.
The LoraWAN protocol adapter has been extended with support for Live Objects provider.
In the Quarkus variants of the MongoDB device registry and the Hono auth component, the provided metrics did not contain the default set of tags, as used in the other Hono components (e.g. host or component-name). This has been fixed.
The device registry components now support the reporting of Kafka client metrics.
The Java source code level of the Hono code has been raised from 11 to 17. This also means that a JDK version 17 or later is required for building and running Hono.
The mechanism to delete obsolete hono.command_internal.* Kafka topics could have deleted still used topics in case the Kubernetes API server gave information about the running containers with a delay of several seconds. This has been fixed.
The native executable based images of protocol adapters failed to deserialize a registration assertion if it included command endpoint information that had been configured for the device. This has been fixed.

API Changes

The MQTT adapter no longer accepts the + wild card character for the tenant ID in a topic filter used for subscribing to commands.
Support for configuration properties that had been marked as deprecated in Hono versions before 2.0.0 has been removed.
The Kura protocol adapter has been removed. Eclipse Kura gateways starting with version 4 can still connect to Hono using Hono’s standard MQTT adapter.
The file based device registry has been removed.
The Spring Boot based variant of the AMQP protocol adapter has been removed.
The Spring Boot based variant of the HTTP protocol adapter has been removed.
The Spring Boot based variant of the MQTT protocol adapter has been removed.
Usage and implementations of the Device Connection API have been removed.
The Spring Boot based variant of the Command Router has been removed.
The amqp-device client has been moved from the client module to the new client-device-amqp module. The org.eclipse.hono.client.device.amqp.AmqpAdapterClientFactory class is superseded by the new org.eclipse.hono.client.device.amqp.AmqpAdapterClient class.
Removed deprecated startServiceClient, stopServiceClient and updateLastGateway methods of class org.eclipse.hono.adapter.AbstractProtocolAdapterBase.
Removed deprecated org.eclipse.hono.util.BufferResult class.
Removed deprecated org.eclipse.hono.service.http.AbstractEventBusHttpEndpoint class.
The client module has been removed. Its deprecated classes have been removed and the remaining classes have been moved to the client-common, amqp-connection and amqp-common modules. The classes for configuring AMQP client connections have been moved from the core to the amqp-connection module.
The core module no longer supports Java 8 but has been changed to require at least Java 17 as all the other modules.
The core module is no longer an OSGi bundle.
The org.eclipse.hono.service.auth.AuthenticationService’s method signatures have been changed to return a Future instead of accepting a Handler<AsyncResult>.
The org.eclipse.hono.client.amqp.connection.ConnectionFactory’s method signatures have been changed to return a Future instead of accepting a Handler<AsyncResult>.
Removed unused classes org.eclipse.hono.util.EventBusMessage and org.eclipse.hono.util.MessageTap.
Moved org.eclipse.hono.util.BaseMessageFilter to service-base module.
Moved org.eclipse.hono.util.AmqpErrorException to amqp-connection client module.
Moved org.eclipse.hono.util.TimeUntilDisconnectNotification to application client module.
The org.eclipse.hono.util.RequestResponseResult class hierarchy’s dependency on the Proton-J ApplicationProperties class has been removed. Instead, the constructors now accept a standard Map containing the properties.
Moved several AMQP 1.0 specific constants from org.eclipse.hono.util.Constants to org.eclipse.hono.client.amqp.connection.AmqpConstants in the amqp-connection client module.
Moved the code for injecting and extracting a tracing context to/from AMQP 1.0 messages to the amqp-connection client module.
Moved org.eclipse.hono.util.TelemetryExecutionContext to adapter-base module.
The amqp-device client module no longer supports including arbitrary properties in telemetry, event and command response messages because it was undefined how these properties would be processed by the AMQP protocol adapter.
The application client module no longer supports including arbitrary properties in command messages because it was undefined how these properties would be processed by the Hono components.
The order of the method parameters of the org.eclipse.hono.application.client.CommandSender interface have been changed so that mandatory parameters come first.
The hono-service-base-quarkus module has been removed. Its content has been integrated in the hono-service-base module.
The hono-adapter-base-quarkus module has been removed. Its content has been integrated in the hono-adapter-base module.
The amqp-device client no longer requires supplying a tenant ID when creating a client or invoking any of its methods.
The Hono components now export tracing data using the OpenTelemetry Protocol (OTLP). See the Monitoring & Tracing guide for details on how to configure the trace sampling and the OpenTelemetry Collector endpoint to send the traces to. The jaeger Maven build profile used for including the Jaeger client in the Hono images has been removed. In order to forward Hono traces to a Jaeger back-end, the OpenTelemetry Collector should be configured accordingly.
The Hono components now support reading and writing trace context information from and to messages exchanged with other applications in the format defined by the W3C Trace Context and the W3C Baggage specifications. The Jaeger native propagation format used in earlier Hono versions is not supported any more.
The Hono command line client has been re-implemented using the Picocli framework. The synopsis of the client has been changed to provide for a richer user experience. The Getting Started guide has been updated to use the new command line client as well.
The Hono protocol adapter, command router and device registry Maven modules and Docker images have been renamed, removing the -vertx and -quarkus parts from the names.
The hono-adapters-quarkus and hono-services-quarkus Maven modules, used as parent modules for protocol adapter and service implementations, have been renamed to hono-adapters-parent and hono-services-parent, respectively.
The hono.messages metrics have been renamed to hono.telemetry and hono.messages.received has been renamed to hono.telemetry.processing.duration.
The hono.commands metrics have been renamed to hono.command.
The hono.downstream metrics have been renamed to hono.amqp, hono.downstream.sent has been renamed to hono.amqp.delivery.duration and hono.downstream.full has been renamed to hono.amqp.nocredit.
Hono’s service components and protocol adapters now use the Quarkus SmallRye Health extension to implement the health check and metrics endpoints. That means the health check server configuration is now done via the corresponding Quarkus configuration properties and not via hono.healthCheck properties any more. See the Monitoring & Tracing guide for details on how to configure the health check server.

Deprecations

Support for implementing readiness and liveness checks based on Vert.x Health Checks has been deprecated and will be removed in a future version. New health checks should be implemented according to MicroProfile Health.

1.12.3

Fixes & Enhancements

The mechanism to delete obsolete hono.command_internal.* Kafka topics could have deleted still used topics in case the Kubernetes API server gave information about the running containers with a delay of several seconds. This has been fixed.
The CoAP adapter did not properly consider the reduced minimum RAM requirements for starting up when running as a native executable on a SubstrateVM. This could have resulted in the adapter not starting up at all, if configured with less than ~150MB of RAM. This has been fixed.
The HTTP protocol adapter and Device Registry now support a configuration property for explicitly setting the idle timeout. The timeout is configured with the property idleTimeout. This determines if a connection will timeout and be closed if no data is received or sent within the idle timeout period. The idle timeout is in seconds. A zero value means no timeout is used.
The MQTT adapter skipped command or error (the first one) subscription if both are requested for the same device. This has been fixed.
The native executable based Lora adapter container image failed to forward Lora meta information in messages being sent downstream. This has been fixed.
Upgraded to JJWT 0.11.5 which contains additional security guards against an ECDSA bug in Java SE versions 15-15.0.6, 17-17.0.2, and 18 (CVE-2022-21449). Note: if your application does not use these JVM versions, you are not exposed to the JVM vulnerability. The CVE is not a bug within JJWT itself - it is a bug within the above listed JVM versions, and the JJWT 0.11.5 release adds additional precautions within JJWT in case an application team is not able to upgrade their JVM in a timely manner.
The Auth server failed to create a token when configured with an ECC based private key that does not use the P-256 curve. This has been fixed.
The CoAP protocol adapter now uses Eclipse Californium 2.7.3.

1.12.2

Fixes & Enhancements

The Quarkus variant of the MongoDB device registry did not accept HTTP endpoint credentials that worked with the Spring Boot based variant because password hashes were created in lower case instead of upper case. This has been fixed.
In some cases, invalid HTTP requests to the HTTP adapter or the Device Registry caused a response with a 500 status code instead of the corresponding 4xx status code. This has been fixed.
HonoConnectionImpl instances failed to release/close the underlying TCP/TLS connection when its disconnect or shutdown method had been invoked. This has been fixed.
In the Quarkus variants of the MongoDB device registry and the Hono auth component, the provided metrics did not contain the default set of tags, as used in the other Hono components (e.g. host or component-name). This has been fixed.

1.12.1

Fixes & Enhancements

The Quarkus variant of the MongoDB based device registry failed to start up if the hono.mongodb.dbName property was not set. However, the DB name should not be required if a connection string is set using the hono.mongodb.connectionString property. This has been fixed.
Using OpenSSL with the Quarkus based variant of Hono components did not work as described in the Secure Communication guide. This has been fixed.
The connection pool configuration for the HotRod client in the Quarkus variant of the Command Router component didn’t support using property names in camel-case. This has been fixed.

1.12.0

New Features

The Mongo DB based device registry now supports multiple tenants to use the same trust anchors for authenticating devices based on client certificates. The devices belonging to such tenants need to indicate the tenant identifier using the Server Name Indication extension during their TLS handshake with a protocol adapter. Please refer to the Device Registry Management API for details on how to configure tenants accordingly. Please refer to the protocol adapter user guides and the Device Identity concept page for details regarding device authentication based on client certificates.
A Quarkus based variant of the MongoDB device registry has been added.

Fixes & Enhancements

The device registry containers might not have started up properly when used with Kafka as the messaging infrastructure. This has been fixed.
The MongoDB device registry did not accept HTTP endpoint credentials that worked with Hono <= 1.10 because password hashes were created in lower case instead of upper case. This has been fixed.
The native executable of the Command Router component did not start when configured with an embedded cache. This has been fixed.
There was an issue trying to send connection events concerning unauthenticated MQTT/AMQP devices. This has been fixed.

Deprecations

The Spring Boot based variant of the MongoDB device registry has been deprecated and marked for removal in Hono 2.0.0.

API Changes

The MongoDB device registry now uses PBKDF2 as default hash algorithm for the HTTP endpoint credential verification. Hono deployments updated from an earlier version with password hashes created using the previous SHA-512 default need to either create new password hashes or set hono.registry.http.auth.hashAlgorithm to SHA512. See the MongoDB based registry configuration guide for details.

1.11.3

Fixes & Enhancements

HonoConnectionImpl instances failed to release/close the underlying TCP/TLS connection when its disconnect or shutdown method had been invoked. This has been fixed.
In the Quarkus variant of the Hono auth component, the provided metrics did not contain the default set of tags, as used in the other Hono components (e.g. host or component-name). This has been fixed.

1.11.2

Fixes & Enhancements

The MongoDB device registry did not accept HTTP endpoint credentials that worked with Hono <= 1.10 because password hashes were created in lower case instead of upper case. This has been fixed.
The native executable of the Command Router component did not start when configured with an embedded cache. This has been fixed.
There was an issue trying to send connection events concerning unauthenticated MQTT/AMQP devices. This has been fixed.

1.11.1

Fixes & Enhancements

The device registry containers might not have started up properly when used with Kafka as the messaging infrastructure. This has been fixed.

1.11.0

New Features

The Authentication Server now also reports the hono.connections.attempts metric which counts the number of authentication attempts made by clients.
The JDBC DB based registry now also supports enforcement of registration limits configured at the tenant level. In particular, the maximum number of devices and the maximum number of credentials per device can be set in a tenant’s registration-limits property. Please refer to the User Guide for details.
Kafka clients used by a component can now be configured individually instead of all clients of a type using the same configuration. The prefixes that are prepended to the configuration properties of the native Kafka client have changed. For existing configuration properties prefixed with hono.kafka.commonClientConfig properties, no change is needed. Other configurations with specific consumer/producer/admin client properties have to be adapted. Please refer to the Hono Kafka Client Configuration Guide for details.
The protocol adapters now include a ttl header/property in every message being forwarded, regardless of message type. This allows a consumer of a message to easily determine if the message should be processed or considered expired already. The device registry supports the definition of default ttl values for the different types of messages at both the tenant and device level. Please refer to the Tenant API for details regarding the corresponding default property names to use.

Fixes & Enhancements

The number of credits that the Mongo DB based registry would flow to a newly connected client could not be set using the documented environment variable HONO_CREDENTIALS_SVC_RECEIVERLINKCREDIT. Instead, the initial link credit can be configured using environment variable HONO_REGISTRY_AMQP_RECEIVERLINKCREDIT. The Mongo DB based registry’s admin guide has been updated accordingly.
When using Kafka messaging, there could possibly be an exception during startup of the Command Router component, meaning the component was potentially only available after a number of startup attempts. This has been fixed.
The Quarkus based variant of the Lora protocol adapter did not start up unless the HONO_LORA_COMMANDENABLEDTENANTS environment variable had been set. This has been fixed by removing this (unused) variable from the Lora adapter altogether.
All downstream messages that can be consumed via Hono’s north bound APIs now include a creation-time header which indicates the point in time at which the message has been created.
The error messages returned by protocol adapters when sending commands received via Kafka now include a reasonable error description.
The tenant’s configuration property auto-provisioning-device-id-template is now extended to support more subjectDN’s attributes namely Organizational Unit Name (OU) and Organization Name (O). For more information please refer to the Device Registry Management API.
The container images published by the Hono project are now built on top of Java 17 base images provided by the Eclipse Temurin project.
The Hono container images released with tag 1.10.0 failed to start up when not running as user root because the Java process was lacking authority to create a temporary directory in the file system’s root folder (/). This has been fixed.
Command response messages published via Kafka did not contain the tenant_id header. This has been fixed.
Hono’s components now support configuring the ciphers used in the TLS handshake when connecting to Infinispan servers. For the Command Router component remote data grid configuration this can be done by setting the hono.commandRouter.cache.remote.sslCiphers property.
When using Kafka messaging, the Hono components will now retry creating the Kafka clients in case the Kafka bootstrap server URLs are not yet resolvable. This will prevent unnecessary restarts of the Hono components during initial deployment.
The native image variant of the Command Router component failed to connect to an Infinispan server using SASL SCRAM. This has been fixed.
The lora adapter supports unconfirmed uplink data for the firefly provider.
The poll timeout used by the Kafka consumer clients in the Hono components can now be configured individually. Please refer to the Hono Kafka Client Configuration Guide for details.

Deprecations

The Spring Boot based variant of the protocol adapters has been deprecated and marked for removal in Hono 2.0.0.
The Kura 3 protocol adapter has been deprecated and marked for removal in Hono 2.0.0. Support for Kura version 4 and later is still available by means of Hono’s standard MQTT adapter.

API Changes

The hono.kafka.defaultClientIdPrefix configuration property needs to be removed from existing configurations. Configuring parts of the created Kafka client identifiers should usually not be needed any more. To still set a custom part, the client.id property value may be used instead. It is adopted as prefix for created client identifiers.
A new API for notifications among Hono components has been introduced. For Hono deployments using an AMQP messaging network, it has to be made sure that addresses with the notification/ prefix are configured to use multicast. See the tests/src/test/resources/qpid/qdrouterd-with-broker.json file for an example Qpid Dispatch Router configuration.

1.10.1

Fixes & Enhancements

The number of credits that the Mongo DB based registry would flow to a newly connected client could not be set using the documented environment variable HONO_CREDENTIALS_SVC_RECEIVERLINKCREDIT. Instead, the initial link credit can be configured using environment variable HONO_REGISTRY_AMQP_RECEIVERLINKCREDIT. The Mongo DB based registry’s admin guide has been updated accordingly.
When using Kafka messaging, there could possibly be an exception during startup of the Command Router component, meaning the component was potentially only available after a number of startup attempts. This has been fixed.
The Quarkus based variant of the Lora protocol adapter did not start up unless the HONO_LORA_COMMANDENABLEDTENANTS environment variable had been set. This has been fixed by removing this (unused) variable from the Lora adapter altogether.
The Hono container images released with tag 1.10.0 failed to start up when not running as user root because the Java process was lacking authority to create a temporary directory in the file system’s root folder (/). This has been fixed.
Command response messages published via Kafka did not contain the tenant_id header. This has been fixed.
Hono’s components now support configuring the ciphers used in the TLS handshake when connecting to Infinispan servers. For the Command Router component remote data grid configuration this can be done by setting the hono.commandRouter.cache.remote.sslCiphers property.
When using Kafka messaging, protocol adapters may have shown a prolonged delay in processing command & control messages in certain situations in which one Kafka cluster node was shortly unavailable. This has been fixed.
The native image variant of the Command Router component failed to connect to an Infinispan server using SASL SCRAM. This has been fixed.
The lora adapter supports unconfirmed uplink data for the firefly provider.

1.10.0

New Features

The JDBC and Mongo DB based registry implementations now support configuration of a regular expression that should be used to validate authentication identifiers (user names) of hashed-password credentials. Please refer to the corresponding Admin Guides for details.
The Command Router component is now able to determine the state of protocol adapter instances, preventing command & control messages to be sent to already terminated adapter instances. Hono Kubernetes deployments where not all protocol adapters are part of the same Kubernetes cluster and namespace that the Command Router component is in, need to disable this feature via the hono.commandRouter.svc.kubernetesBasedAdapterInstanceStatusServiceEnabled property. Please refer to the Command Router Admin Guide for details.
The authentication provider used to guard access to the Mongo DB based registry implementation’s HTTP endpoint can now be configured using environment variables. Please refer to the registry’s Admin Guide for details.
The Registry Management API has been extended with an operation to delete all devices (including credentials) of a tenant. Both the Mongo DB and the JDBC based registry implementations support this operation.
The protocol adapters and the Command Router component now by default report a set of metrics concerning the clients used for sending and receiving messages via Kafka. Please refer to the Hono Kafka Client Configuration Guide for additional information.

Fixes & Enhancements

The Quarkus based variants of Hono’s components now support configuring the Hot Rod client with a key and/or trust store in order to enable TLS secured connections to Infinispan servers and to authenticate using a client certificate.
The MongoDB based DeviceManagementService erroneously removed the original device registration when trying to register a new device using the existing device’s identifier. This has been fixed.
The Mongo DB based registry implementation now uses a proper DB index to find credentials by type and authentication ID. This will speed up query execution significantly when there are a lot of devices registered for a tenant.
The JDBC based device registry’s get Credentials operation used by the protocol adapters now also supports matching credentials against a given client context.
The device registry implementations did not return a JSON object in a response to a failed request as specified in the Device Registry Management API. This has been fixed.
The MongoDB based registry erroneously rejected requests that would result in multiple tenants having an empty set of trusted CAs. This has been fixed.
The ttl header in downstream messages with Kafka had been set in seconds instead of milliseconds, as defined by the API specification. This has been fixed.

1.9.1

Fixes & Enhancements

The Quarkus based variants of Hono’s components now support configuring the Hot Rod client with a key and/or trust store in order to enable TLS secured connections to Infinispan servers and to authenticate using a client certificate.
The MongoDB based DeviceManagementService erroneously removed the original device registration when trying to register a new device using the existing device’s identifier. This has been fixed.
The Mongo DB based registry implementation now uses a proper DB index to find credentials by type and authentication ID. This will speed up query execution significantly when there are a lot of devices registered for a tenant.
The JDBC based device registry’s get Credentials operation used by the protocol adapters now also supports matching credentials against a given client context.
The device registry implementations did not return a JSON object in a response to a failed request as specified in the Device Registry Management API. This has been fixed.
The tracing output in error scenarios has been improved in the Mongo DB based device registry.
The MongoDB based registry erroneously rejected requests that would result in multiple tenants having an empty set of trusted CAs. This has been fixed.

1.9.0

New Features

The Mongo DB based registry now supports enforcement of registration limits configured at the tenant level. In particular, the maximum number of devices and the maximum number of credentials per device can be set in a tenant’s registration-limits property. Please refer to the Mongo DB User Guide for details.
Hono now sends a device provisioning notification when a device or a gateway is successfully auto-provisioned.
Northbound applications sending request/response Command & Control messages via Kafka will now receive a notification about a failed command delivery via a command response message. See the Command & Control API for Kafka for details.
The Mongo DB based device registry implementation now supports transparent (symmetric) encryption of Pre-Shared Key secrets. Please refer to the user guide for details regarding configuration.

Fixes & Enhancements

The value of the properties auto-provisioned and auto-provisioning-notification-sent had always been false when retrieving device registration information using the MongoDB based registry implementation. This has been fixed.
The LoRA protocol adapter will now skip registering itself for receiving commands for a given gateway device if that gateway device has no command endpoint defined. The adapter will now also free command consumer resources when the idle timeout of the corresponding tenant (configured via the hono.lora.tenantIdleTimeout property) has elapsed and the tenant is already removed or disabled.
The device registry implementations have already supported the limitation of the body size of requests to the /tenants and /credentials resources of the HTTP based Device Registration Management API. However, the admin guides did not cover the corresponding HONO_REGISTRY_HTTP_MAXPAYLOADSIZE configuration variable yet. The /devices resources have been added to the scope of the feature and the admin guides have been amended accordingly.
The protocol adapters now invoke the set last known gateway Command Router service operation a lot less frequently, reducing the load on the Command Router component if gateways send messages on behalf of devices at a high rate. The last known gateway entry for a device is now set with a delay of at most 400ms as part of a batch request.
The keyStorePassword and trustStorePassword properties of the Hono clients now also support specifying a file to read the password from. If the property value starts with file: then the value after the prefix is interpreted as as the path to a file to read the password from.
The registry implementations failed to reject a request to update a device’s empty set of credentials, e.g. right after the device has been created, if the request contained a secret having an ID. In fact, the registry implementations would have accepted such a request even if the secrets did not contain a password/key/etc at all but only the identifier. This has been fixed.
A potential issue processing Command & Control messages from a Kafka cluster while Command Router instances are getting stopped or started has been fixed.
The rate at which the Command Router component handles Command & Control messages from a Kafka cluster is now limited to prevent potential memory issues and reduce the load on dependent services. The limit value is adopted from the configured max.poll.records Kafka consumer configuration value.
The default properties of the Hono CLI tool have been updated to match typical Hono installations. It provides now 3 types of profiles that need to be combined: 1. select the “mode”: receiver or command; 2. select the “target”: sandbox or local (aims for deployment in Minikube but works for every deployment of the Helm chart); 3. select the “messaging-type”: kafka (if not set, it defaults to AMQP-based messaging). For details refer to the file application.yml of the CLI module.

Deprecations

The file based device registry implementation has been deprecated and will be removed in a future version of Hono. Please use the Mongo DB or JDBC based registry implementations instead. The JDBC based registry can be configured to use an H2 database in either embedded or in-memory mode. The former can be used to persist data to the local file system while the latter keeps all data in memory only.
The MongoDB based registry implementation no longer supports the configuration variables for disabling modification of existing data. In real life deployments this feature has no meaning because write access to data will need to be authorized more explicitly anyway, e.g. at the tenant level.

API Changes

The client classes used by the protocol adapters for accessing the device registry, the Command Router and the south bound C&C APIs have been reorganized into dedicated modules. In particular, the adapter, adapter-amqp and adapter-kafka modules have been resolved into modules command, command-amqp, command-kafka, registry, registry-amqp, telemetry, telemetry-amqp and telemetry-kafka. This allows Hono’s components to define more specific dependencies on client classes that they require. This change should have no effect on application clients.
The set last known gateway Command Router API operation has been extended to also support setting multiple values in one request.

End of life

The Maven profiles for compiling in support for exporting metrics to Graphite and InfluxDB have been removed.

1.8.3

Fixes & Enhancements

The Quarkus based variants of Hono’s components now support configuring the Hot Rod client with a key and/or trust store in order to enable TLS secured connections to Infinispan servers and to authenticate using a client certificate.
The Mongo DB based registry implementation now uses a proper DB index to find credentials by type and authentication ID. This will speed up query execution significantly when there are a lot of devices registered for a tenant.
The MongoDB based registry erroneously rejected requests that would result in multiple tenants having an empty set of trusted CAs. This has been fixed.

1.8.2

Fixes & Enhancements

The MQTT adapter didn’t close the CONNECT tracing span and didn’t report metrics on failed connection attempts. This has been fixed.
The registry implementations failed to reject a request to update a device’s empty set of credentials, e.g. right after the device has been created, if the request contained a secret having an ID. In fact, the registry implementations would have accepted such a request even if the secrets did not contain a password/key/etc at all but only the identifier. This has been fixed.
A potential issue processing Command & Control messages from a Kafka cluster while Command Router instances are getting stopped or started has been fixed.

1.8.1

Fixes & Enhancements

Letting the trace sampling settings of the Hono components be defined via sampling strategies served by the Jaeger Collector did not work for components using Quarkus native images. This has been fixed.
Command messages with no payload could not be sent to an MQTT device. This has been fixed.
The value of the properties auto-provisioned and auto-provisioning-notification-sent are always false while retrieving device registration information using the MongoDB based registry implementation. This has been fixed now.
The Command Router service could have gotten into a state of very high CPU utilization when protocol adapters submitted non-existing tenant IDs for which command routing should be re-enabled. This has been fixed.
The LoRA protocol adapter will now free command consumer resources when the idle timeout of the corresponding tenant (configured via the hono.lora.tenantIdleTimeout property) has elapsed and the tenant is already removed or disabled.
The device registry implementations have already supported the limitation of the body size of requests to the /tenants and /credentials resources of the HTTP based Device Registration Management API. However, the admin guides did not cover the corresponding HONO_REGISTRY_HTTP_MAXPAYLOADSIZE configuration variable yet. The /devices resources have been added to the scope of the feature and the admin guides have been amended accordingly.

1.8.0

New Features

The CoAP adapter now supports authentication of client certificates using ECDSA based cipher suites.
The JDBC-based device registry implementation now supports the automatic creation of the database schema, both for device registration and tenant data. This is especially useful for experimental setups where an embedded database, such as H2 provides, is sufficient. To enable automatic schema creation, activate the application profile create-schema.
Hono’s components now support configuration of supported TLS cipher suites. The cipher suites can be configured separately for both the endpoints exposed by the components as well as the clients used for accessing service endpoints exposed by other components. Please refer to the corresponding admin guides for details regarding the corresponding configuration variables.
Hono now supports auto-provisioning of gateways. For more information please refer to the Gateway Provisioning concept and to the Device Registry Management API on how to configure a tenant’s trusted CA authority for that.
Now the tenant configuration supports a new property namely auto-provisioning-device-id-template in it’s trusted CA section. During auto-provisioning of devices and gateways, the device identifier is generated based on this template and used for the device registration. For more information please refer to the Device Provisioning concept and to the Device Registry Management API on how to configure a tenant’s trusted CA authority for that.
The Hono CLI supports now Kafka as a messaging system. Please refer to the module’s README file for examples of using the CLI to receive events and telemetry data and send commands.
The example business application supports now Kafka as a messaging system. Please refer to the Developer Guide for details.

Fixes & Enhancements

The CoAP adapter did not correctly track the time it took to forward a command message to a device. This has been fixed.
Sending requests using the Hono AMQP request-response client erroneously increased the hono.downstream.timeout metric. This has been fixed.
Support for uplink messages from the Embedded LNS on MultiTech gateways.
The hono.connections.attempts metric has been extended with a cipher-suite tag which contains the name of the cipher suite that is used in a device’s attempt to establish a TLS based connection to an adapter.
The Quarkus based Command Router native image failed to start an embedded cache that was configured to persist data to the local file system. This has been fixed.
The delivery of a command message sent to an AMQP device potentially didn’t get settled if the connection to the AMQP device got disconnected. This has been fixed.
The Prometheus based resource limit checks’ performance has been improved. This should result in considerably less load on the Prometheus server when failing over all of a crashed/stopped adapter instance’s device connections.
The Hono component container images now contain the Gson library which is required by the Jaeger client for processing sampling strategy configuration retrieved from the Jaeger Collector.
The Kafka based implementation of the north bound application client org.eclipse.hono.application.client.kafka.impl.KafkaApplicationClientImpl now supports sending commands and receiving responses in a request/response fashion.

Deprecations

The org.eclipse.hono.client.ApplicationClientFactory, org.eclipse.hono.client.AsyncCommandClient and org.eclipse.hono.client.CommandClient classes have been deprecated. Client code should use org.eclipse.hono.application.client.ApplicationClient instead.

1.7.4

Fixes & Enhancements

Letting the trace sampling settings of the Hono components be defined via sampling strategies served by the Jaeger Collector did not work for components using Quarkus native images. This has been fixed.
Command messages with no payload could not be sent to an MQTT device. This has been fixed.
The value of the properties auto-provisioned and auto-provisioning-notification-sent are always false while retrieving device registration information using the MongoDB based registry implementation. This has been fixed now.
The Command Router service could have gotten into a state of very high CPU utilization when protocol adapters submitted non-existing tenant IDs for which command routing should be re-enabled. This has been fixed.
The LoRA protocol adapter will now free command consumer resources when the idle timeout of the corresponding tenant (configured via the hono.lora.tenantIdleTimeout property) has elapsed and the tenant is already removed or disabled.
The device registry implementations have already supported the limitation of the body size of requests to the /tenants and /credentials resources of the HTTP based Device Registration Management API. However, the admin guides did not cover the corresponding HONO_REGISTRY_HTTP_MAXPAYLOADSIZE configuration variable yet. The /devices resources have been added to the scope of the feature and the admin guides have been amended accordingly.

1.7.3

Fixes & Enhancements

The Hono component container images now contain the Gson library which is required by the Jaeger client for processing sampling strategy configuration retrieved from the Jaeger Collector.

1.7.2

Fixes & Enhancements

The Quarkus based Command Router native image failed to start an embedded cache that was configured to persist data to the local file system. This has been fixed.
The delivery of a command message sent to an AMQP device potentially didn’t get settled if the connection to the AMQP device got disconnected. This has been fixed.

1.7.1

Fixes & Enhancements

The CoAP adapter did not correctly track the time it took to forward a command message to a device. This has been fixed.
The downstream mapping endpoint was not correctly serialized which resulted in not being able to send commands using the downstream mapping endpoint. This has been fixed.
When using Kafka as messaging system, the Command Router now creates the internal Command & Control topic with the replication factor defined in the broker default.replication.factor setting.
Sending requests using the Hono AMQP request-response client erroneously increased the hono.downstream.timeout metric. This has been fixed.

1.7.0

New Features

Apache Kafka is now supported as a messaging system for command messages. This can be enabled by configuring protocol adapters to use Hono’s new Kafka-based client. Please refer to Hono Kafka Client Configuration for details. The new Command & Control API for Kafka defines how applications can use Apache Kafka to send command messages to devices. Note that support for Kafka based messaging is still considered an experimental feature.
The Device Registry Management API has been extended now to support an optional unique identifier for trust anchors belonging to a tenant. The file, JDBC and MongoDB based device registries support this feature. Please refer to the Device registry management API for details.
The LoraWAN protocol adapter has been extended with support for The Things Stack provider.
The LoraWAN protocol adapter now supports command and control for providers Chirpstack, Firefly and Loriot.
Added (experimental) Quarkus based variant of the Authentication service.
Added (experimental) Quarkus based variant of the CoAP protocol adapter.
Added (experimental) Quarkus based variant of the Command Router component.
The container images for the (experimental) Quarkus based variant of Hono components are now being published on Docker Hub as well. The JVM based image names contain a -quarkus suffix whereas the native image names contain a -quarkus-native suffix. Note that the Quarkus based protocol adapter images do not support using the Device Connection service but require a connection to the Command Router service being configured instead.
The MQTT adapter now lets devices subscribe on a new error topic to get informed about errors during the processing of telemetry, event or command response message. With such an error subscription in place, the default behaviour on such errors is now to keep the MQTT connection open. Please refer to the MQTT Adapter User Guide for details.
The MQTT adapter now supports mapping the command payload through an external http service.
The Command Router component has been promoted from tech preview to fully supported.
The AMQP adapter now closes the network connection to the device if any terminal errors happen. Please refer to the AMQP Adapter User Guide for details.

Fixes & Enhancements

The common configuration property for setting the vert.x instance’s max-event-loop-execute-time had erroneously been documented as HONO_VERTX_MAX_EVENT_LOOP_EXECUTE_TIME_MILLIS, accepting an integer representing the duration as number of milliseconds. However, the correct property is named HONO_VERTX_MAX_EVENT_LOOP_EXECUTE_TIME and accepts an ISO-8601 Duration string instead of an integer.
The MQTT adapter failed to handle a command response message if the corresponding tenant object wasn’t available in the cache. This has been fixed.
A failed connection attempt in the default org.eclipse.hono.connection.ConnectionFactory implementation could have led to the AMQP connection not getting closed, occupying connection resources. This has been fixed.
Validation of MQTT topics containing property bags has been improved, preventing unhandled exceptions.
The hugo themes for the Hono website and the documentation have been updated to the latest versions respectively. In order for the site module build to succeed with the hugo binary installed locally, the site/homepage/themes/hugo-universal-theme and site/documentation/themes/hugo-theme-learn folders need to be deleted. They will automatically be (re-)created as part of the build.
The Infinispan client used by the protocol adapters, the Device Connection and Command Router services has been updated to version 11.0.9. The syntax of configuration file used for defining an embedded cache in the Device Connection and/or Command Router service has changed as documented in the Infinispan version details.
The Command Router no longer uses the embedded-cache Spring profile in order to configure an embedded cache. Instead, the Command Router determines the type of cache (embedded or remote) by means of the HONO_COMMANDROUTER_CACHE_REMOTE_SERVERLIST configuration variable. Please refer to the Command Router Admin Guide for details.
The Prometheus based resource limit checks can now be configured with a time out for establishing the TCP connection to the Prometheus server. This is useful to limit the time it takes to invoke the Prometheus Query API. Please refer to the Protocol Adapter Common Configuration guide for details.

API Changes

The already deprecated classes org.eclipse.hono.service.cache.SpringBasedExpiringValueCache and org.eclipse.hono.service.cache.SpringCacheProvider have been removed.
The org.eclipse.hono.service.AbstractApplication and org.eclipse.hono.service.AbstractBaseApplication classes have been moved to org.eclipse.hono.service.spring.AbstractApplication and org.eclipse.hono.service.spring.AbstractApplication in the newly added service-base-spring module respectively.
The existing mapper configuration has been renamed to downstream-message-mapper.
The Command Router component now requires the configuration of a tenant service client. Please refer to Tenant Service Connection Configuration for details.

End of Life

The build-docker-image build profile is no longer activated automatically if the docker.host Maven property is set. This has been changed in order to prevent the build-docker-image and build-native-image profiles being activated at the same time when running something like
```
mvn clean install -Ddocker.host=tcp//host:port -Pbuild-native-image
```
Activating the build-docker-image profile by default can easily be achieved by adding -Pbuild-docker-image to the MAVEN_OPTS environment variable instead.

1.6.2

Fixes & Enhancements

The CoAP adapter did not correctly track the time it took to forward a command message to a device. This has been fixed.
Sending requests using the Hono AMQP request-response client erroneously increased the hono.downstream.timeout metric. This has been fixed.

1.6.1

Fixes & Enhancements

The common configuration property for setting the vert.x instance’s max-event-loop-execute-time had erroneously been documented as HONO_VERTX_MAX_EVENT_LOOP_EXECUTE_TIME_MILLIS, accepting an integer representing the duration as number of milliseconds. However, the correct property is named HONO_VERTX_MAX_EVENT_LOOP_EXECUTE_TIME and accepts an ISO-8601 Duration string instead of an integer.
The MQTT adapter failed to handle a command response message if the corresponding tenant object wasn’t available in the cache. This has been fixed.
A failed connection attempt in the default org.eclipse.hono.connection.ConnectionFactory implementation could have led to the AMQP connection not getting closed, occupying connection resources. This has been fixed.
Validation of MQTT topics containing property bags has been improved, preventing unhandled exceptions.
The protocol adapters might have run into a situation where devices connected to adapters did no longer receive commands when using the Command Router service. The problem occurred when a Command Router service instance had been restarted while one or more protocol adapters where connected to it. This has been fixed.

1.6.0

New Features

Apache Kafka is now supported as a messaging system for events and telemetry messages. This can be enabled by configuring protocol adapters to use Hono’s new Kafka-based client. Please refer to Hono Kafka Client Configuration for details.
New APIs have been added for the Kafka-based messaging. Please refer to Telemetry API for Kafka and Event API for Kafka for the specifications.
The MQTT adapter now allows clients to indicate whether they want the target device’s tenant and/or device IDs to be included in the topic used when publishing commands.
The caching behavior of the protocol adapters’ AMQP based registry clients has been changed. All adapter Verticle instances now share a single cache instance per service. In particular, there is a single cache for all responses returned by the Tenant, Device Registration and Credentials service respectively. In addition, each cache is now being used for all responses to requests regardless of the tenant. Consequently, the service client configurations’ responseCacheMinSize and responseCacheMaxSize properties now determine the overall number of responses that can be cached per service. In previous versions the properties determined the number of entries per client instance and tenant. The new approach allows for better control over the maximum amount of memory being used by the cache and should also increase cache hits when deploying multiple adapter Verticle instances. The org.eclipse.hono.adapter.client.registry.amqp.ProtonBasedTenantClient now makes sure that only a single request to the Tenant service is issued when multiple (parallel) get method invocations run into a cache miss. This should reduce the load on the Tenant service significantly in scenarios where devices of the same tenant connect to an adapter at a high rate, e.g. in when re-connecting after one or more adapter pods have crashed.
The Device Registry Management API’s update credentials operation has been extended to allow specifying the auth-id and validity period implicitly by means of including a (Base64 encoded) client certificate in the new cert property. This can be used instead of specifying the client certificate’s subject DN and public key’s validity period explicitly in the auth-id and secrets properties. This should make setting the correct auth-id value much less error prone.
Hono now supports auto-provisioning of devices that connect via gateway. For more information please refer to the Device Provisioning concept and to the Device registry management API on how to create a device registration for a gateway which is enabled for auto-provisioning.
The Device Registry Management API has been extended now to support searching tenants with optional filters, paging and sorting options. Please refer to the Device registry management API for details.
The MongoDB based device registry now supports searching tenants with optional filters, paging and sorting options.

Fixes & Enhancements

The Mongo DB based Credentials service implementation failed to return the credentials matching the given type and auth-id if multiple credentials of the same type but with different auth-id values were registered for a device. This has been fixed.
The Mongo DB based registry container would have failed to start if the connection to the Mongo DB could not be established quickly enough. This has been fixed by decoupling the creation of indices from the start up process.
The protocol adapters erroneously indicated a client related error to devices if the downstream AMQP container rejected a message with an amqp:resource-limit-exceeded error condition. This has been fixed so that the adapters now correctly indicate a server related problem instead.
The containers for the Device Registry implementations, the Authentication server, the Device Connection and Command Router services did not shut down gracefully upon receiving a SIGTERM signal. This has been fixed.
The LoRA protocol adapter failed to start due to a missing bean declaration. This has been fixed.

Deprecations

The org.eclipse.hono.service.cache.SpringCacheProvider and org.eclipse.hono.service.cache.SpringBasedExpiringValueCache classes have been deprecated to further reduce the dependency on Spring Boot. Clients should use org.eclipse.hono.service.cache.CaffeineCacheProvider and org.eclipse.hono.service.cache.CaffeineBasedExpiringValueCache instead.
Most of the public interfaces of the legacy client module have been deprecated. Client code should be adapted to use the corresponding interfaces and implementations from the clients/adapter, clients/adapter-amqp and clients/application-amqp modules instead.
The Authentication server’s HONO_AUTH_SVC_PERMISSIONS_PATH configuration property has been changed to no longer accept generic Spring resource URIs. The value is now required to be a file system path. The path may still contain a file:// prefix in order to not break existing configurations. However, users are encouraged to remove the prefix as it will no longer be supported in versions starting with 2.0.0. The default permissions file has been removed from the Authentication server code base. Consequently, permissions can no longer be loaded from the class path using a classpath:// URI. In practice this should have no impact because the Hono chart comes with a default permissions file which the Authentication server is pre-configured to load from the file system.

1.5.2

Fixes & Enhancements

The protocol adapters erroneously indicated a client related error to devices if the downstream AMQP container rejected a message with an amqp:resource-limit-exceeded error condition. This has been fixed so that the adapters now correctly indicate a server related problem instead.
The containers for the Device Registry implementations, the Authentication server, the Device Connection and Command Router services did not shut down gracefully upon receiving a SIGTERM signal. This has been fixed.
The LoRA protocol adapter failed to start due to a missing bean declaration. This has been fixed.

1.5.1

Fixes & Enhancements

The Mongo DB based Credentials service implementation failed to return the credentials matching the given type and auth-id if multiple credentials of the same type but with different auth-id values were registered for a device. This has been fixed.
When using the Command Router or Device Connection service component with an embedded cache, a cache configuration file was required. Now, a default configuration will be used if no configuration file is given.
The Mongo DB based registry container would have failed to start if the connection to the Mongo DB could not be established quickly enough. This has been fixed by decoupling the creation of indices from the start up process.
The AMQP and MQTT adapters would erroneously forward commands to unauthorized gateway devices under certain conditions. This has been fixed.

1.5.0

New Features

The CoAP adapter has been promoted from experimental to fully supported.
The Hono Client now supports several configuration properties that can be used to limit its resource usage. In particular the AMQP connection’s max-frame-size, the AMQP session’s incoming window size and the max-message-size of receiver links can be configured (and thus limited).
A new way of routing Command & Control messages from the AMQP messaging network to the target protocol adapters has been introduced. For that, a new Command Router service component is used, receiving command messages and routing them to the appropriate protocol adapters. Protocol adapters supply routing information to the component by means of a new Command Router API. Protocol adapters can be configured to either use that new API or they can continue using the now deprecated Device Connection API instead, meaning command routing will be done without using the Command Router.
The pre-built Hono Docker images available from Docker Hub now include the Jaeger OpenTracing client.

Fixes & Enhancements

The file based as well as the MongoDB based registry implementations now remove the shared-key from PSK credentials returned in the response of the Management API’s get credentials operation.
The Device Registry Management API erroneously declared the plaintext password conveyed in the update credentials operation’s request payload as a Base64 encoded byte array instead of a plain string. This has been fixed.
The file based as well as the Mongo DB based registry implementations had failed to do both updating an existing secret (referred to by ID) and adding a new secret to the same credentials in a single request. This has been fixed.
The property names for specifying the patterns for validating Tenant and Device IDs have been fixed in the admin guides for the file based and the Mongo DB based registry implementations.
The registry implementations did not accept X.509 credentials in an update Credentials request. They also failed to remove existing credentials of a device if they were not included in an update Credentials request. This has been fixed.
The file based device registry also now supports searching devices for a tenant with optional filters, paging and sorting options. Please refer to the Device registry management API for details.
The wildcards ? and * are now supported by the search devices operation in the MongoDB based device registry. Please refer to the Device registry management API for details.
Command messages that have their payload in an AMQP body section whose type isn’t supported in Hono now get rejected, instead of getting forwarded to the device with an empty payload.
The authentication providers in Hono use CredentialsObject.getCandidateSecrets to retrieve valid secrets. The secrets are currently filtered based on their validity period regardless of whether the status is enabled or not. This has been fixed now, so that the disabled secrets are filtered out.
The MQTT adapter now supports specifying the content-type of a telemetry/event message via a MQTT property bag.
The MQTT adapter now sets the MQTT client identifier as client-id in the payload of a Credentials API get operation request also when authenticating a device using the username/password mechanism. Previously that was only done for the client certificate authentication mechanism.
The HTTP adapter did not properly forward the QoS level for events when the qos-level header is not set or set to AT_MOST_ONCE. This has been fixed.
An HTTP device sending a command response request with no Content-Type header meant that the northbound application received a message with an empty content type. Now, the application/octet-stream content type is set, as it is also done for telemetry/event HTTP requests with no Content-Type header.
There were errors sending Connection Events via the Events API if the corresponding tenant didn’t have a non-default max-ttl resource limit configuration. This has been fixed.

API Changes

The deprecated configuration property singleTenant of the protocol adapters and the device registry has been removed.
The default pattern for valid device identifiers used for the file based and the MongoDB based registry implementations now also contains a colon for compatibility with Eclipse Ditto.

End of Life

The hono-jmeter Maven module along with the JMeter plugin that is contained in it hasn’t been updated for over a year and is also not used in any automated test runs. JMeter has turned out not to be the best choice for conducting load tests of Hono because it is difficult to generate the needed AMQP message load with its (blocking) thread based execution model. The JMeter plugin therefore has been removed.

1.4.5

Fixes & Enhancements

The tenant timeout mechanism doesn’t close command consumer resources anymore if there are still active command subscriptions from AMQP or MQTT devices of the corresponding tenant.
The Mongo DB based Credentials service implementation failed to return the credentials matching the given type and auth-id if multiple credentials of the same type but with different auth-id values were registered for a device. This has been fixed.
The Mongo DB based registry container would have failed to start if the connection to the Mongo DB could not be established quickly enough. This has been fixed by decoupling the creation of indices from the start up process.
The AMQP and MQTT adapters would erroneously forward commands to unauthorized gateway devices under certain conditions. This has been fixed.

1.4.4

Fixes & Enhancements

The HTTP adapter did not properly forward the QoS level for events when the qos-level header is not set or set to AT_MOST_ONCE. This has been fixed.
An HTTP device sending a command response request with no Content-Type header meant that the north bound application received a message with the content type set to an empty string. Now, the content type property isn’t set in this case.
There were errors sending Connection Events via the Events API if the corresponding tenant didn’t have a non-default max-ttl resource limit configuration. This has been fixed.

1.4.3

Fixes & Enhancements

The file based as well as the Mongo DB based registry implementations now remove the shared-key from PSK credentials returned in the response of the Management API’s get credentials operation.
The Device Registry Management API erroneously declared the plain text password conveyed in the update credentials operation’s request payload as a Base64 encoded byte array instead of a plain string. This has been fixed.
The file based as well as the Mongo DB based registry implementations had failed to do both updating an existing secret (referred to by ID) and adding a new secret to the same credentials in a single request. This has been fixed.
The property names for specifying the patterns for validating Tenant and Device IDs have been fixed in the admin guides for the file based and the Mongo DB based registry implementations.
The registry implementations did not accept X.509 credentials in an update Credentials request. They also failed to remove existing credentials of a device if they were not included in an update Credentials request. This has been fixed.
The AMQP protocol adapter did accept messages from clients (devices) exceeding the adapter’s configured max-message-size. This has been fixed and the adapter now closes the link to the device in this case.

API Changes

The default pattern for valid device identifiers used for the file based and the MongoDB based registry implementations now also contains a colon (:) for compatibility with Eclipse Ditto.

1.4.0

New Features

The protocol adapters now report connection attempts made by devices in a new metric. In particular, the metric includes a tag reflecting the outcome of the attempt to establish a connection and the reason for failure. Please refer to the Metrics API for details.
A new Quarkus based HTTP protocol adapter is now available. This adapter version provides better memory consumption and startup times comparing to the existing one.
The LoraWAN protocol adapter has been extended with support for the Actility Enterprise provider.
The LoraWAN protocol adapter has been extended with support for the Orbiwise provider.
Added metrics for tracking the RTT between sending an AMQP message to receiving the disposition.
The CoAP adapter now supports configuration of the timeoutToAck parameter at the tenant level in addition to the adapter level. If set, the tenant specific value is used for all devices of the particular tenant. If not set, the value defined at the adapter level is used.
The Device Registry Management API has been extended now to support searching devices for a tenant with optional filters, paging and sorting options. Please refer to the Device registry management API for details.
The MongoDB based device registry now supports searching devices for a tenant with optional filters, paging and sorting options.

Fixes & Enhancements

The MongoDB based device registry now checks for tenant existence during device registration and credentials management operations.

Deprecations

The configuration property singleTenant of the protocol adapters and the device registry is now deprecated and planned to be removed in a future release. The use case of a system with just a single tenant should be realized by configuring just one tenant in the device registry.
The HONO_REGISTRY_REST_* configuration properties of the file based device registry have been deprecated in favor of corresponding properties with the HONO_REGISTRY_HTTP_ prefix.

1.3.2

Fixes & Enhancements

The HTTP adapter did not properly forward the QoS level for events when the qos-level header is not set or set to AT_MOST_ONCE. This has been fixed.
An HTTP device sending a command response request with no Content-Type header meant that the northbound application received a message with the content type set to an empty string. Now, the content type property isn’t set in this case.
There were errors sending Connection Events via the Events API if the corresponding tenant didn’t have a non-default max-ttl resource limit configuration. This has been fixed.

1.3.1

Fixes & Enhancements

The file based as well as the Mongo DB based registry implementations now remove the shared-key from PSK credentials returned in the response of the Management API’s get credentials operation.
The Device Registry Management API erroneously declared the plain text password conveyed in the update credentials operation’s request payload as a Base64 encoded byte array instead of a plain string. This has been fixed.
The file based as well as the Mongo DB based registry implementations had failed to do both updating an existing secret (referred to by ID) and adding a new secret to the same credentials in a single request. This has been fixed.
The property names for specifying the patterns for validating Tenant and Device IDs have been fixed in the admin guides for the file based and the Mongo DB based registry implementations.
The registry implementations did not accept X.509 credentials in an update Credentials request. They also failed to remove existing credentials of a device if they were not included in an update Credentials request. This has been fixed.
The AMQP protocol adapter did accept messages from clients (devices) exceeding the adapter’s configured max-message-size. This has been fixed and the adapter now closes the link to the device in this case.

API Changes

The default pattern for valid device identifiers used for the file based and the MongoDB based registry implementations now also contains a colon (:) for compatibility with Eclipse Ditto.

1.3.0

New Features

The LoraWAN protocol adapter has been extended with support for the ChirpStack provider.
Hono’s integration tests can now be run with a Jaeger back end in order to collect tracing information.
The AMQP 1.0 event message based Connection Event producer now sets a TTL on the event messages it produces. The TTL is the max TTL configured at the tenant level.
A new Device Registry implementation based on MongoDB database is now available in Hono. Please refer to the MongoDB Device Registry User Guide for additional information.
Hono protocol adapters can now be configured to use address rewriting when opening AMQP 1.0 links to the messaging network. This allows an easier deployment in multi-tenant messaging environments. Please refer to the Hono Client Configuration Guide for additional information.

Fixes & Enhancements

An admin guide for the CoAP adapter has been added.
The Prometheus based resource limits checker now supports configuring a query timeout. Please refer to Resource Limits Checker Configuration for additional information.
When sending a command message to a device, the AMQP adapter now waits for a configurable period of time (default is 1 second) for the acknowledgement from the device. If none is received, the downstream command sender gets back a released outcome. Please refer to the sendMessageToDeviceTimeout property description in the AMQP Adapter admin guide for additional information.
The client for storing device connection information to a data grid now supports configuring the name of the cache to store the data in.
When the connection to a device is closed or lost, a protocol adapter instance will now stop listening for commands targeted at the device.
The AMQP adapter before accepting any connections checks if the connection limit is exceeded or not and if the adapter is enabled or not. These checks are currently done inside the AmqpAdapterSaslAuthenticatorFactory. Thereby, if any of these checks failed, the AMQP adapter reported authentication failure instead of the actual reason. This has been fixed now.
The AMQP adapter did not consider the HONO_CONNECTIONEVENTS_PRODUCER configuration variable to set a Connection Event producer. This has been fixed.
The logging Connection Event producer now supports configuring the level at which information should be logged. The producer type none has been added to explicitly turn off connection event reporting altogether. Please refer to the Common Configuration admin guide for details.
The packages org.eclipse.hono.service.credentials, org.eclipse.hono.service.management, org.eclipse.hono.service.management.credentials, org.eclipse.hono.service.management.device, org.eclipse.hono.service.management.tenant, org.eclipse.hono.service.registration and org.eclipse.hono.service.tenant have been moved from the service-base to the device-registry-base module.
The Device Connection service did return a 500 error code if no last known gateway could be found for a device ID. This has been fixed so that the service now returns a 404 in that case as specified by the Device Connection API.
The cache based Device Connection service implementation now applies a lifespan of 28 days when setting/updating cache entries containing last known gateway information. This means no global expiration configuration is needed anymore for the cache.
Protocol adapters failed to re-establish receiver links for commands to be routed after loss of connection to the AMQP Messaging Network. This has been fixed.
The AMQP adapter reported an incorrect number of connections if resource limits had been defined and exceeded. This has been fixed.
The device registry management HTTP endpoints now reject requests to register or update objects containing unknown properties. In the past such properties had been simply ignored.
The Device Registry Management API has been amended with example messages and more thorough description of operations.
The CoAP adapter has been enhanced to asynchronously look up a device’s PSK during the DTLS handshake. This will allow the adapter to handle a lot more handshakes concurrently. The adapter also employs a more efficient message de-duplicator which reduces the adapter’s memory footprint.

API Changes

The getRemoteContainer method in org.eclipse.hono.client.HonoConnection has been renamed to getRemoteContainerId.
The getName method in org.eclipse.hono.connection.ConnectionFactory has been removed and an additional connect method has been added.
The set command-handling protocol adapter instance operation of the Device Connection API has been extended to support an additional parameter which can be used to indicate the maximum amount of time that the given information is to be considered valid.
The hono-core module no longer embeds any external classes by default. This includes the OpenTracing API and Spring Crypto classes. You can still embed the classes, as in Hono versions 1.2.x and before, by enabling the Maven profile embed-dependencies (e.g. using the command line switch -Pembed-dependencies). By default this profile is not active.
The org.eclipse.hono.client.DeviceRegistration interface’s get methods have been removed because the Device Registration API does not define a corresponding operation. Consequently, the C&C functionality of the Kerlink Lora provider which relied on the get method has been removed.
Protocol adapters implementing the org.eclipse.hono.service.AbstractAdapterConfig class now need to implement the getAdapterName method. The customizeDownstreamSenderFactoryConfig method has been renamed to getDownstreamSenderFactoryConfigDefaults, while now returning properties instead of working on given ones. The new method name now more accurately conveys what the method is used for. The same change has been applied to the other customize[*]Config methods in the AbstractAdapterConfig class.
The file based as well as the MongoDB based device registry implementations now disallow certain special characters in device and tenant identifiers. The configuration properties HONO_REGISTRY_HTTP_TENANT_ID_PATTERN and HONO_REGISTRY_HTTP_DEVICE_ID_PATTERN (and corresponding ones with prefix HONO_REGISTRY_REST for the file based registry) can be used to override the patterns for matching valid identifiers. Please refer to the file based registry or MongoDB based registry configuration guide for details.

Deprecations

The configuration property HONO_MQTT_COMMAND_ACK_TIMEOUT of the MQTT adapter is now deprecated and planned to be removed in a future release. Use HONO_MQTT_SEND_MESSAGE_TO_DEVICE_TIMEOUT instead.

1.2.4

Fixes & Enhancements

The HonoConnection implementation didn’t use a delay before a reconnect attempt after a certain number of reconnect attempts (58 with the default configuration) had already failed. This has been fixed.
An error when freeing Command & Control related resources of an idle tenant has been fixed.
The Hotrod based DeviceConnectionClientFactory has been improved to prevent locking of objects in a clustered cache.
The AMQP adapter reported an incorrect number of connections if resource limits had been defined and exceeded. This has been fixed.

1.2.3

Fixes & Enhancements

The Device Connection service did return a 500 error code if no last known gateway could be found for a device ID. This has been fixed so that the service now returns a 404 in that case as specified by the Device Connection API.
The cache based Device Connection service implementation now applies a lifespan of 28 days when setting/updating cache entries containing last known gateway information. This means no global expiration configuration is needed anymore for the cache.
Protocol adapters failed to re-establish receiver links for commands to be routed after loss of connection to the AMQP Messaging Network. This has been fixed.

API Changes

The org.eclipse.hono.client.DeviceRegistration interface’s get methods have been removed because the Device Registration API does not define a corresponding operation. Consequently, the C&C functionality of the Kerlink Lora provider which relied on the get method has been removed.

1.2.2

Fixes & Enhancements

Commands might not have been routed to the target device or gateway if multiple Verticle instances were deployed in a protocol adapter instance. This has been fixed.
The example registry’s admin guide has been amended with some missing configuration variables.
The documentation of the underlying concepts of Hono’s Command & Control functionality has been updated to reflect recent changes.
Some dependencies have been updated to more recent versions fixing potential vulnerabilities.

1.2.1

Fixes & Enhancements

The AMQP adapter didn’t report any metrics anymore. This has been fixed.
The CoAP and HTTP adapters’ user guide now correctly documents the 413 status code returned in response to a request that contains a payload exceeding the configured maximum size.

1.2.0

New Features

The protocol adapters can now be configured with a direct connection to a data grid for storing device connection information. This has the advantage of saving the network hop to the Device Connection service. Please refer to the protocol adapter Admin Guides for details.
The Prometheus based resource limits check can now be configured with a trust store, key material and/or a username and password in order to be able to connect to a Prometheus server that requires TLS and/or client authentication.
A Java client for the communication with the AMQP protocol adapter has been added. It can be used to implement devices, (protocol) gateways and for testing purposes. For more information refer to AMQP Adapter Client for Java.
Devices can now be configured with groups of gateways that are allowed to act on behalf of the device. This makes it easier to support scenarios in which a device may roam between multiple gateways. The HTTP based management API has been adapted accordingly.
The CoAP adapter now supports forwarding commands to devices in the response body of requests for uploading telemetry data and/or events, analogous to the HTTP adapter. Please note that the CoAP adapter is still considered experimental and its device facing API is therefore still subject to change.

Fixes & Enhancements

When a message arrived, the message limit checks failed to calculate the payload size of the incoming message based on the configured minimum message size. Instead, it used the actual payload size to verify if the message limit has been exceeded or not. This has been fixed now.
The Command & Control implementation in the protocol adapters has been optimized to use far fewer consumer links to the AMQP Messaging Network, saving up on resources. Before this change, the protocol adapters created a separate receiver link for each device that wanted to receive commands. Now each protocol adapter instance creates only a single receiver link over which all commands for all devices connected to the adapter instance are transmitted.
The base classes for implementing a device registry have been moved into their own device-registry-based module.
The example device registry’s AMQP and HTTP endpoints do no longer exchange incoming request messages and outgoing response messages with the service implementation verticles over the Vert.x EventBus. This reduces complexity and should improve throughput as messages no longer need to be serialized anymore.
A first version of the CoAP User Guide has been added.
A concept page explaining the different ways devices can be connected to Hono’s protocol adapters has been added. There is also example code illustrating how a protocol gateway which connects to the AMQP adapter can be implemented.
If both AMQP and Kafka messaging systems are configured, then Command & Control messages will be received from both systems. A command response message from a device will by default be forwarded using the messaging system that the corresponding command message was received in.

API Changes

The device registry credentials endpoint will no longer hand out sensitive details for hashed-password secrets. pwd-hash, salt and hash-function are stored by the device registry but not returned to the user. Each secret is given an ID which is now returned, along with the other metadata (time validity and optional fields).
The tenant and devices endpoints of the management HTTP API now accept creation requests without a body. As there is no mandatory field, having a mandatory body was confusing.
The methods of the service base classes CredentialsManagementService, CredentialsService, DeviceConnectionService, DeviceManagementService, RegistrationService, TenantManagementService and TenantService have been refactored to now return a Vert.x Future instead of taking a Handler as an argument.
The CommandConsumerFactory interface has been renamed to ProtocolAdapterCommandConsumerFactory and method signatures have been changed slightly. Also, a new initialize method has been added to be called on protocol adapter startup.
The AMQP Messaging Network now has to be configured in such a way that protocol adapters can send and receive messages on the command_internal/* instead of the control/* address pattern.
The Device Registry Management API has been extended to support the definition of Gateway Groups which can be referenced in a device’s viaGroups property in order to authorize all gateways that are a member of any of the groups to act on behalf of the device.

1.1.2

API Changes

The org.eclipse.hono.client.DeviceRegistration interface’s get methods have been removed because the Device Registration API does not define a corresponding operation. Consequently, the C&C functionality of the Kerlink Lora provider which relied on the get method has been removed.

1.1.1

Fixes & Enhancements

The FireFly LoRa adapter now supports mapping of the mic property.
A bug preventing the lora and SigFox adapters to start up correctly has been fixed.
The MQTT adapter failed to accept command response messages from authenticated gateways that had been published to the command//${device-id}/res/${req-id}/${status} topic. This has been fixed and the adapter now correctly uses the gateway’s tenant in this case.
When a north bound application sent a command to a device that is connected via a gateway, the AMQP adapter set the gateway’s ID instead of the device’s ID in the command response forwarded to the application. This has been fixed.

1.1.0

New Features

The Sigfox and LoRaWAN adapters now report metrics analogously to the other protocol adapters.
With the release of Eclipse Californium 2.0.0, the CoAP adapter became an official part of the Hono release. The adapter also supports tracking of request processing using OpenTracing but is still considered experimental.
A lorawan provider has been added for the loriot network provider.
Hono’s protocol adapters now support Server Name Indication in order to allow devices to establish a TLS connection with adapters using a tenant specific server certificate and host name. Please refer to the Secure Communication admin guide for details.
Hono now supports auto-provisioning of devices that authenticate with X.509 client certificates. For more information please refer to the Device Provisioning concept and for details to the Tenant API and the Credentials API.
The Hono Auth Server and Device Registry components now support configuring the SASL mechanisms advertised to a client connecting to these components. This can be used to restrict the support to only one of the SASL PLAIN and EXTERNAL mechanisms instead of both.
A new metric namely hono.connections.authenticated.duration has been introduced to track the connection duration of the authenticated devices. Please refer to the Metrics API for more details.
The protocol adapters that maintain connection state can now be configured to verify the connection duration limit for each tenant before accepting any new connection request from the devices. Please refer to the resource-limits section for more details.
Hono’s example device registry now supports configuring a time out for processing requests from clients. This is configured using the property sendTimeOutInMs in org.eclipse.hono.config.ServiceConfigProperties.
Hono’s Helm chart is now available from the Eclipse IoT Packages chart repository. All future development of the chart will be done in the IoT Packages project only. The deployment guide has been adapted accordingly.

Fixes & Enhancements

Hono’s Helm chart now supports configuring resource requests and limits of the container images.
The MQTT adapter now includes a device’s MQTT client ID in its request to retrieve the device’s credentials. This additional information can be used by device registry implementations when determining the device identity.
The domain name of the Hono Sandbox has been changed to hono.eclipseprojects.io. It will still be available at the old domain name for some time as well, though.
Hono’s OpenTracing instrumentation has been upgraded to Opentracing 0.33.0. The example deployment now uses the Jaeger Java client in version 0.35.2 and the Jaeger 1.16 agent and back end components.
Some of the environment variable names documented in the user guides which can be used for configuring Hono components had not been recognized during start up of the components. In particular, the names for configuring the connection to the Device Connection service and for configuring a heath check server have been fixed.
The AMQP adapter now correctly accepts command response messages from devices that do not contain any payload. Such responses are useful to only convey a status code in reply to a command.

API Changes

The already deprecated endpoints with the control prefix have been removed. The northbound and southbound Command & Control endpoints can now only be used with the command and command_response prefixes (or the respective shorthand version). Note that the AMQP Messaging Network still needs to be configured in such a way that protocol adapters can send and receive messages on the control/* address pattern. This is now used for internal communication between protocol adapters only.
The create method in org.eclipse.hono.client.HonoConnection now requires its Vertx parameter to be not null.

1.0.4

API Changes

The org.eclipse.hono.client.DeviceRegistration interface’s get methods have been removed because the Device Registration API does not define a corresponding operation. Consequently, the C&C functionality of the Kerlink Lora provider which relied on the get method has been removed.

1.0.3

Fixes & Enhancements

Hono’s Helm Chart now correctly configures Prometheus based resource limit checks if a Prometheus server is being used for collecting metrics.
Some OpenTracing spans used for tracking processing of messages haven’t properly been finished. This has been fixed.
Protocol adapters are now able to process messages while still trying to re-establish connections to other services after a connection loss. This might result in fewer messages being rejected in such situations.

1.0.2

Fixes & Enhancements

The example deployment now also works with Kubernetes 1.16 using Helm 2.15 and later.
The Hono chart can now also be deployed using the recently released Helm 3. In fact, Helm 3 is now the recommended way for deploying Hono as it doesn’t require installation of any Helm specific components to the Kubernetes cluster.
The example data grid which can be deployed using the Hono Helm chart can now be scaled out to more than one node.
Under rare circumstances an HTTP adapter instance might have gotten into a state where a device’s requests to receive commands could no longer be processed successfully anymore until the adapter instance had been restarted. This has been fixed.
A potential issue has been identified where some command messages might not get sent to the corresponding gateway. The scenario here involves the gateway sending event/telemetry messages via HTTP with a hono-ttd header in order to receive commands, and doing so with multiple concurrent requests for different devices. To resolve this issue, the corresponding tenant can be configured with a support-concurrent-gateway-device-command-requests option set to true in the ext field of an adapters entry of type hono-http. Note that with this option it is not supported for the authenticated gateway to send one message with a hono-ttd header and no device id to receive commands for any device that has last sent a telemetry or event message via this gateway.

1.0.1

Fixes & Enhancements

The AMQP protocol adapter now requests devices to send traffic periodically in order to prevent a time out of the connection. This way the adapter is able to detect and close stale connections which is important to reliably close the device’s corresponding command consumer. The time period after which the adapter should consider a connection stale can be configured using an environment variable. Please refer to the AMQP adapter’s admin guide for details.
The example deployment using the Helm chart correctly creates the DEFAULT_TENANT again.

1.0.0

New Features

A tenant can now be configured with a max-ttl which is used as an upper boundary for default TTL values configured for devices/tenants. Please refer to the Tenant API for details. The AMQP, HTTP, MQTT and Kura protocol adapters consider this property when setting a TTL on downstream event messages.
A protocol adapter can now be configured with a timeout for idle tenants. When there has been no communication between a protocol adapter instance and the devices of a tenant, the former one releases allocated resources of the tenant. Currently this means that it closes AMQP links and stops reporting metrics for this tenant. The timeout is configured with the property tenantIdleTimeout for a protocol adapter. Please refer to the protocol adapter configuration guides for details.
The accounting period for the message limit checks can now be configured as monthly. In this case the data usage for a tenant is calculated from the beginning till the end of the (Gregorian) calendar month. Refer resource limits for more information.
The devices can now indicate a time-to-live duration for event messages published using the HTTP and MQTT adapters by setting the hono-ttl property in requests explicitly. Please refer to the HTTP Adapter and MQTT Adapter for details.
The device registry HTTP management API now properly implements cross-origin resource sharing (CORS) support, by allowing the service to be exposed to configured domains (by default, it’s exposed to all domains).
The org.eclipse.hono.util.MessageHelper now provides convenience factory methods for creating new downstream messages from basic properties. org.eclipse.hono.service.AbstractProtocolAdapterBase has been adapted to delegate to these new factory methods.
Hono’s protocol adapters can now use multiple trusted certificate authorities per tenant to authenticate devices based on client certificates. The list of trusted certificate authorities can be managed at the tenant level using the Device Registry Management API.
Authenticated gateway devices can now subscribe to commands for specific devices. Before, gateways could only subscribe to commands directed at any of the devices that the gateway has acted on behalf of. With the new feature of also being able to subscribe to commands for specific devices, northbound applications will get notified of such a subscription along with the specific device id.
Now a max-ttd value, which is used as an upper boundary for the hono-ttd value specified by the devices, can be set as an extension property in the adapters section of the tenant configuration.

API Changes

The already deprecated legacy metrics support has been removed.
The already deprecated legacy device registry and the corresponding base classes, which had been deprecated as well, have been removed.
The topic filters used by MQTT devices to subscribe to commands has been changed slightly to better fit the addressing scheme used by the other protocol adapters. The existing topic filters have been deprecated but are still supported. Please refer to the MQTT adapter user guide for details.
The interface ResourceLimitChecks and its implementation classes have been moved to package org.eclipse.hono.service.resourcelimits from org.eclipse.hono.service.plan. Also the configuration parameters for the resource limits were renamed from hono.plan to hono.resourceLimits. Please refer to the protocol adapter configuration guides for more information.
The response payload of the get Tenant operation of the Tenant API has been changed to contain a list of trusted certificate authorities instead of just a single one. This way, protocol adapters can now authenticate devices based on client certificates signed by one of multiple different trusted root authorities defined for a tenant. All standard protocol adapters have been adapted to this change. The Tenant JSON schema object used in the tenant related resources of the Device Registry Management API has also been adapted to contain a list of trusted authorities instead of a single one.

Deprecations

The OpenShift specific source-to-image deployment model has been removed in favor of the Helm charts and the Eclipse IoT Packages project. You can still deploy Hono on OpenShift using the Helm charts.
Defining password secrets with user provided password hash, function and salt is deprecated in the device registry management API and will be removed in the upcoming versions. You should use pwd-plain property only going forward.

1.0-M7

New Features

The Hono Helm chart now supports to choose if the example Device Registry, example AMQP Messaging Network and/or the example Jaeger back end should be deployed and used with the Hono components or not. In the latter case, the chart now also supports setting configuration properties for using an already existing AMQP Messaging Network, Device Registry and/or Jaeger back end.
A data grid based implementation of the Device Connection API has been added to Hono. This implementation can be used in production environments using a highly scalable data grid for storing device connection information. The service can be used instead of the simple implementation provided by the example Device Registry by means of setting a configuration property when deploying using the Helm chart.
A tenant can now be configured so that all OpenTracing spans created when processing messages for that specific tenant will be recorded in the tracing backend (overriding the default sampling strategy that might only record a certain percentage of traces). See Monitoring & Tracing for more details.

API Changes

The obsolete method variants of reportTelemetry in org.eclipse.hono.service.metric.Metrics have been removed. The new variants of this method accept an additional parameter of type TenantObject.
The already deprecated org.eclipse.hono.service.AbstractProtocolAdapterBase.getRegistrationAssertion method has been removed. The alternate variant of the getRegistrationAssertion method which accepts an additional OpenTracing span parameter should be used.
The already deprecated getRegistrationAssertion, getTenantConfiguration, sendConnectedTtdEvent, sendDisconnectedTtdEvent and sendTtdEvent methods in org.eclipse.hono.service.AbstractProtocolAdapterBase have been removed. The alternate variant of these methods which accepts an additional OpenTracing span parameter should be used.

Deprecations

The deprecated Kura adapter is no longer deployed by default by the Helm chart. However, it can still be deployed by means of setting a configuration property.

1.0-M6

New Features

Implementation of the new HTTP management API for tenants, devices and credentials.
The health check endpoints of services can now be called securely via TLS. Please refer to the protocol adapter configuration guides for the new parameters available.
The Tenant API now optionally allows specifying minimum message size. If it is specified, then the payload size of the incoming telemetry, event and command messages are calculated in accordance with the minimum message size by the AMQP, HTTP and MQTT protocol adapters and then recorded in the metrics system. See Metrics for more details.

Fixes & Enhancements

The automatic reconnect handling of the HonoConnection implementation has been improved and now applies an exponential back-off algorithm. The behavior can be configured using the ${PREFIX}_RECONNECT_* configuration variables. Please refer to the Hono Client Configuration guide for details regarding these new variables.
The message limit checks is now extended to include command and control messages. Please refer to the resource limits for details.
The health check server endpoint will now bind to a default port value of 8088 if no values are set explicitly in the configuration. It is also possible to start both a secure and an insecure server (using different ports) Refer to the Monitoring configuration guide for details.

API Changes

With the implementation of the new HTTP management API for the device registry, the class hierarchy for implementing device registry was significantly refactored. This also includes the deprecation of a list of classes and tests. Also see Device registry changes for more information.
The complete interfaces, and the base and complete implementation classes for services got deprecated, and are planned to be removed in a future release. Also see Device registry changes for more information.
The example Device Registry that comes with Hono now implements the new HTTP management API. Consequently, the URI endpoints for managing the content of the registry have changed accordingly.
The configuration parameters for the health check endpoint were moved from hono.app to hono.healthCheck and renamed. hono.app.healthCheckPort is now hono.healthCheck.insecurePort and hono.app.healthCheckBindAddress is now hono.healthCheck.insecurePortBindAdress. Please refer to the protocol adapter configuration guides for additional information on the new naming.

Device registry changes

The section summarizes changes made for 1.0-M5 in the device registry.

During the development of Hono 1.0, we defined a new HTTP API for managing information stored in the device registry. This API replaces the current, provisional API, which was originally intended for tests to manipulate the file based device registry during system tests. The new HTTP based API is intended to replace the existing HTTP API, as well as the management part of the AMQP based API.

The first major change is, that all the complete classes got deprecated. As they are based on the services for the protocol adapters. And those services are no longer considered to be used for managing information. The replacement for those classes are the new management APIs.

Each of the three APIs got a companion API for management, which are located in the org.eclipse.hono.service.management base package.

The class hierarchy was decoupled in order to make it easier to implement those services. The new design only requires to implement a service, which is not based on any other interface. And while your concrete implement still can implement the Verticle interface, this is no longer a requirement.

Also the base classes got deprecated. Instead of inheriting the common functionality, to bind to the event bus, that functionality got moved into new event bus adapter classes, which take the reference of a service, and bind this service to the event bus instead of using inheritance. Those change make it possible to re-use much of the functionality, but do not impose the requirement to inherit from either the complete or base classes. And this finally allows your service implementation to be extend your specific base class, and re-use common Hono functionality at the same time. This allows service implementations to implement both the standard API, as well as the management API in the same class. As Java does not allow inheritance from multiple classes, this was not possible before.

The new default file based device registry, was modified to use the new class hierarchy and support the new management model.

The device registry, which was provided in 1.0-M4 and before, is still part of the source tree, but was moved to services/device-registry-legacy. It is there to show the compatibility with the older class hierarchy, using the, now deprecated, base and complete classes. Newer implementations should not be build on this model.

Clients of the base variants of the services, like the protocol adapters, do not need to make any changes.

Implementations of the device registry services, using the existing base and complete can re-use that model, but are encouraged to migrate to the new model as soon as possible, as the legacy model is planned to be removed. The only impacting change is that the service interfaces no longer extend from Verticle directly, but that has been moved to the base implementation.

Implementations of the services for protocol adapters (the non-management API), can switch to the new class hierarchy by dropping inheritance to the base class, and starting up a new instance of the corresponding event bus adapter, providing a reference to the service. For the RegistrationService it is also possible to inherit common functionality from AbstractRegistrationService.

Implementations of the services for management need to simply inherit from the new management interfaces, and set up the event bus adapters the same way.

The module device-registry-legacy as well as all classes and interfaces, which got deprecated, are planned to be dropped in 1.1.

1.0-M5

New Features

Hono’s protocol adapters and the other components now support using ECC based server certificates. The protocol adapters also support authenticating devices which present an ECC based client certificate. The example configuration now uses ECC based certificates by default.
Hono now specifies a Device Connection API and contains an exemplary implementation of this API included in the device registry component. The purpose of the API is to be able to set and retrieve information about the connections from devices or gateways to the protocol adapters.
This version implements the new HTTP management API for tenants, devices, and credentials.

Fixes & Enhancements

The Hono Sandbox’s protocol adapters support using the gateway mode again.
The Getting Started guide has been rewritten to use the Hono Sandbox or a local Minikube cluster instead of Docker Swarm.
The MQTT adapter now closes the network connection to device on publish failures.

API Changes

The optional methods of the Tenant API have been removed. Implementations of the Tenant API are encouraged to expose the tenants endpoint defined by Hono’s HTTP based management API instead. Several of the formerly mandatory to include properties of the request and response messages have been made optional or removed altogether. Existing clients should not be affected by these changes, though.
The optional methods of the Device Registration API have been removed. Implementations of the Device Registration API are encouraged to expose the devices endpoint defined by Hono’s HTTP based management API instead. Several of the formerly mandatory to include properties of the request and response messages have been made optional or removed altogether. Existing clients should not be affected by these changes, though.
The response message format of the assert Device Registration operation of the Device Registration API has been changed, replacing the optional gw-supported boolean field with an optional via field. The value of this field contains the list of gateway that may act on behalf of the device on which the operation is invoked.
The methods for invoking the optional operations of the Device Registration API have been removed from org.eclipse.hono.client.RegistrationClient and org.eclipse.hono.client.impl.RegistrationClientImpl.
The optional methods of the Credentials API have been removed. Implementations of the Credentials API are encouraged to expose the credentials endpoint defined by Hono’s HTTP based management API instead. Several of the formerly mandatory to include properties of the request and response messages have been made optional or removed altogether. Existing clients should not be affected by these changes, though.
The control prefix in the northbound and southbound Command & Control endpoints has been renamed to command. The endpoint names with the control prefix are still supported but deprecated. The northbound endpoint for business applications to receive command responses has the command_response prefix now. The old control prefix for the receiver address is also still supported but deprecated.
The deviceId parameter of the getOrCreateCommandClient and getOrCreateAsyncCommandClient methods of the org.eclipse.hono.client.ApplicationClientFactory interface has been removed. This means that a CommandClient or AsyncCommandClient instance can be used to send commands to arbitrary devices of a tenant now. Accordingly, the CommandClient.sendCommand and AsyncCommandClient.sendAsyncCommand methods now require an additional deviceId parameter.
The deprecated methods of org.eclipse.hono.client.HonoConnection have been removed.

1.0-M4

New Features

Default properties can now also be set at the tenant level, affecting all devices belonging to the tenant. Please refer to the protocol adapter user guides for details.
CredentialsClientImpl now supports caching of response data received from a Credentials service based on cache directives. The protocol adapters are now equipped to cache the response from the Credentials Service. The protocol adapters support configuration variables to set the default cache timeout, the minimum and maximum cache sizes for this service.
The example device registry’s Credentials service implementation now includes a cache directive in its response to the get Credentials operation which allows clients to cache credentials of type hashed-password and x509-cert for a configurable amount of time. Please refer to the Device Registry Admin Guide for details regarding the configuration properties to use.
There is now an official specification of an HTTP API for managing the content of a device registry. The HTTP Management API is defined using by means of OpenAPI v3. Note, that the API is not yet implemented by the example device registry that comes with Hono.
The Command & Control feature now supports gateway agnostic addressing of devices. This means that applications are able to send commands to devices without knowing the particular gateway they may be connected to.
The concept and implementation of message limit have been added. The protocol adapters can be now enabled to verify this message limit for each tenant before accepting any telemetry/event messages. Please refer to the resource limits for details.
A basic Sigfox protocol adapter, for use with the Sigfox backend. Please read the Sigfox protocol adapter documentation to learn more about pre-requisites and limitations.

Fixes & Enhancements

vert.x has been updated to version 3.7.0.

API Changes

The org.eclipse.hono.util.RegistrationConstants.FIELD_DEFAULTS constant has been renamed to org.eclipse.hono.util.RegistrationConstants.FIELD_PAYLOAD_DEFAULTS.
The org.eclipse.hono.service.AbstractProtocolAdapterBase.newMessage and org.eclipse.hono.service.AbstractProtocolAdapterBase.addProperties methods have been changed to accept an additional parameter of type TenantObject which may contain default properties defined for the tenant to be included in downstream messages.
The get Registration Information operation of the Device Registration API is not optional anymore, it is now mandatory to implement. For device registry implementations based on the CompleteRegistrationService interface, there is no change needed as the operation is already defined there.
The response message of the assert Device Registration operation does not contain an assertion token anymore. The org.eclipse.hono.service.registration.BaseRegistrationService class has been adapted accordingly.
The already deprecated org.eclipse.hono.client.CommandConsumerFactory.closeCommandConsumer method has been removed.
The response message format of the assert Device Registration operation of the Device Registration API has been changed to include an optional gw-supported boolean field. The value of this field refers to whether the device on which the operation is invoked allows one or more gateways to act on its behalf.
The AMQP sender link address to be used by business applications to send commands to devices has been changed from control/${tenant_id}/${device_id} to control/${tenant_id} with command messages requiring the to property to be set to control/${tenant_id}/${device_id}. Using control/${tenant_id}/${device_id} as sender link address is still possible but gateway agnostic addressing of devices is not supported for such command messages.

Deprecations

Instructions for script based deployment to Kubernetes have been removed from the deployment guide. Using Helm is now the only supported way of deploying Hono to Kubernetes.

1.0-M3

Fixes & Enhancements

The protocol adapters add tracing information about invocations of the Device Registry services again.
The example deployment now uses Qpid Dispatch Router 1.6.0.

1.0-M2

New Features

A new experimental LoRa protocol adapter has been added which (so far) supports the reception of telemetry data and events from devices connected to LoRa network providers and/or LoRa gateways. Note that this adapter is not considered production ready yet. Any help in improving and enhancing the adapter is more than welcome.
The concept and implementation of resource limits have been added. Now a connection limit to define the maximum number of device connections to be allowed per tenant can be configured. The MQTT and AMQP adapters can be enabled to verify this connection limit before accepting any new connections. Please refer to the resource limits for details.

Fixes & Enhancements

The base classes for implementing the AMQP and HTTP endpoints for the Credentials, Tenant and Device Registration APIs now create an OpenTracing Span for tracking the processing of requests at a high level.
The hono-client and hono-core artifacts use Java 8 level again so that they can be used in applications using Java 8.
The protocol adapters now always specify values for the ttd and qos tags when reporting telemetry messages using meter name hono.messages.received. This fixes an issue when using the Prometheus back end where the HTTP adapter failed to report messages that contained a TTD value and others that didn’t.
The Helm based deployment of the device registry has been fixed by adding the secret and deployment entries for the device-identities.json.
Before uploading command responses, the MQTT and AMQP adapters now check whether the device is registered and also the adapter is enabled for the tenant.

API Changes

The hono-client module has undergone several major and incompatible changes. The most important change affects the HonoClient interface which no longer serves as a factory for the arbitrary clients to the Hono service endpoints. It has been renamed to HonoConnection and now only represents the underlying AMQP connection to a peer and provides methods for managing the connection state and registering listeners for arbitrary life-cycle events of the connection. In addition to this, several factory interfaces have been added which can be used to create specific clients to Hono’s arbitrary services. All of the former HonoClient interface’s factory methods have been distributed accordingly to:
- org.eclipse.hono.client.ApplicationClientFactory for creating clients to Hono’s north bound Telemetry, Event and Command & Control API.
- org.eclipse.hono.client.DownstreamSenderFactory for creating clients to Hono’s south bound Telemetry and Event APIs.
- org.eclipse.hono.client.CommandConsumerFactory for creating clients to Hono’s south bound Command & Control API.
- org.eclipse.hono.client.TenantClientFactory for creating clients to Hono’s Tenant API.
- org.eclipse.hono.client.RegistrationClientFactory for creating clients to Hono’s Device Registration API.
- org.eclipse.hono.client.CredentialsClientFactory for creating clients to Hono’s Credentials API.
In this context the org.eclipse.hono.client.MessageSender interface has been changed as follows:
- The send methods have been changed to no longer accept a registration assertion token which became obsolete with the removal of the Hono Messaging component.
- The isRegistrationAssertionRequired method has been removed from the interface.
- All send method variants which accept specific message parameters have been moved into the new org.eclipse.hono.client.DownstreamSender interface which extends the existing MessageSender.
Several changes have been made to the org.eclipse.hono.service.AbstractProtocolAdapterBase class:
- The newMessage and addProperties methods no longer require a boolean parameter indicating whether to include the assertion token in the message being created/amended. Custom protocol adapters should simply omit the corresponding parameter.
- The base class now uses org.eclipse.hono.client.CommandConsumerFactory instead of org.eclipse.hono.client.CommandConnection for creating org.eclipse.hono.client.CommandConsumer instances. The setCommandConnection and getCommandConnection methods have been renamed to setCommandConsumerFactory and getCommandConsumerFactory correspondingly.
- The base class now uses org.eclipse.hono.client.TenantClientFactory instead of org.eclipse.hono.client.HonoClient for creating org.eclipse.hono.client.TenantClient instances. The setTenantServiceClient and getTenantServiceClient methods have been renamed to setTenantClientFactory and getTenantClientFactory correspondingly.
- The base class now uses org.eclipse.hono.client.RegistrationClientFactory instead of org.eclipse.hono.client.HonoClient for creating org.eclipse.hono.client.RegistrationClient instances. The setRegistrationServiceClient and getRegistrationServiceClient methods have been renamed to setRegistrationClientFactory and getRegistrationClientFactory correspondingly.
- The base class now uses org.eclipse.hono.client.CredentialsClientFactory instead of org.eclipse.hono.client.HonoClient for creating org.eclipse.hono.client.CredentialsClient instances. The setCredentialsServiceClient and getCredentialsServiceClient methods have been renamed to setCredentialsClientFactory and getCredentialsClientFactory correspondingly.
- The base class now uses org.eclipse.hono.client.DownstreamSendertFactory instead of org.eclipse.hono.client.HonoClient for creating org.eclipse.hono.client.DownstreamSender instances. The setHonoMessagingClient and getHonoMessagingClient methods have been renamed to setDownstreamSenderFactory and getDownstreamSenderFactory correspondingly.
The org.eclipse.hono.service.auth.device.UsernamePasswordAuthProvider and the org.eclipse.hono.service.auth.device.X509AuthProvider now accept a org.eclipse.hono.client.CredentialsClientFactory instead of a org.eclipse.hono.client.HonoClient in their constructors.
The org.eclipse.hono.adapter.http.HonoBasicAuthHandler and org.eclipse.hono.adapter.http.X509AuthHandler classes have been moved to package org.eclipse.hono.service.http in the service-base module for consistency reasons as all other reusable classes for implementing HTTP services/ adapters are located in that package already.
The org.eclipse.hono.client.HonoClient class has been renamed to org.eclipse.hono.client.HonoConnection to better reflect its sole responsibility for establishing (and maintaining) the connection to a Hono service endpoint.

Deprecations

The optional operations defined by the Tenant, Device Registration and Credentials API have been deprecated. They will be removed from Hono 1.0 altogether. A new HTTP based API will be defined instead which can then be used to manage the content of a device registry.
org.eclipse.hono.client.HonoConnection’s connect method variants accepting a disconnect handler have been deprecated and will be removed in Hono 1.0. Client code should use one of the other connect methods instead and register a org.eclipse.hono.client.DisconnectListener and/or a org.eclipse.hono.client.ReconnectListener to get notified about life-cycle events of the underlying AMQP connection.

1.0-M1

New Features

The AMQP adapter now supports limiting the number of concurrent connections in order to prevent Out of Memory errors. Please refer to AMQP Adapter Configuration for details.
The org.eclipse.hono.client.AsyncCommandClient has been added to support the sending of commands to devices and the receiving of responses in an asynchronous way. This can be used to decouple the sender and receiver from each other.
The org.eclipse.hono.service.tenant.CompleteBaseTenantService class now rejects malformed encodings of public keys/certificates included in a request to add a trust anchor to a tenant.

Deprecations

The HonoClient.closeCommandConsumer() method will be removed in Hono 1.0. The CommandConsumer.close() method should be used instead.

0.9

New Features

The MQTT adapter now supports commands to be published using QoS 1. Please refer to MQTT adapter User Guide for details.
The MQTT adapter now supports limiting the number of concurrent connections in order to prevent running out of resources. Please refer to MQTT Adapter Configuration for details.
The new Helm deployment for Kubernetes has been added. Please refer to Helm based deployment guide for details.

Fixes & Enhancements

org.eclipse.hono.util.RequestResponseResult now provides access to AMQP application-properties conveyed in the response message.
The org.eclipse.hono.service.registration.BaseRegistrationService class now supports authorization of gateways (acting on behalf of a device) against a list of gateway identifiers instead of a single identifier only. For that purpose the via property of the device’s registration information may contain either a single string or a JSON array containing multiple strings. Based on this, a device can now be configured to connect via arbitrary gateways instead of just a single one.

API Changes

The layout and structure of the metrics reported by Hono have been changed substantially. Many of the existing meters and tags have been changed or replaced in order to provide a more consistent set of metrics and increase the value of the information being reported. The legacy metrics still remain unchanged, though. Please refer to the Metrics definition for details.
In case of a failed connection attempt, HonoClientImpl will now determine based on the error whether it will re-try to connect to the peer. Before, reconnect attempts were done unconditionally, by default infinitely or up to the number of times defined in the reconnectAttempts property in the ClientConfigProperties. Now, when the outcome of the SASL handshake received from the peer during connection establishment indicates that invalid credentials were provided or that the server encountered a permanent error when handling the request, no further reconnect attempts will be done.
The deprecated methods have been removed from org.eclipse.hono.client.MessageSender and its implementations.
The Command & Control API’s send a request/response command operation has been changed. The response message to a command now must include the device and tenant identifiers of the device. Including these two properties should make it much easier to implement competing command response consumers in business applications. As a consequence, the org.eclipse.hono.client.CommandResponse’s factory methods have been changed to accept the tenant and device IDs as parameters.
The connectTimeout configuration variable for the HonoClient now defines the time to wait not only for the TCP/TLS connection establishment but also for the SASL handshake and the exchange of the AMQP open frame.
The (already deprecated) Hono Messaging component has been removed from Hono.

Deprecations

The script based deployment to Kubernetes has been deprecated and will be removed in the next version. The Helm based deployment should be used instead.
The sendCommandResponse(String, String, Buffer, Map, int, SpanContext) of the org.eclipse.hono.client.CommandResponseSender interface has been deprecated and will be removed in the next version. Custom protocol adapters should use sendCommandResponse(CommandResponse, SpanContext) instead.

0.9-M2

New Features

The MQTT protocol adapter now supports authentication of devices using X.509 client certificates. Please refer to the MQTT adapter user guide for details regarding configuration.

Fixes & Enhancements

The OpenShift source-to-image (S2I) deployment is now the default OpenShift / OKD deployment. The plain OpenShift deployment, which had been deprecated in Hono 0.8, has been removed.
The protocol adapters can now be configured with a custom DNS timeout value, limiting the time that the adapter will wait for the response to a DNS query. By default, a DNS query will time out after 5 seconds. Please refer to the protocol adapter admin guides for details regarding the new configuration variable.
The following configuration variables have been added to HonoClient:
- connectTimeout: Sets a limit on the time that the client will wait for a TCP/TLS connection with the peer to be established. By default, a connection attempt will time out after 5 seconds.
- idleTimeout: The idle timeout defines the amount of time after which a connection will be closed when no frames have been received from the remote peer. The default value is 16 seconds.
- sendMessageTimeout: Limits the time to wait for a downstream consumer’s acknowledgement of an event or command response message received from a device. The default value is 1 second.
  
  Please refer to the Hono Client Configuration guide for details regarding the new configuration variables.

API Changes

Some of the tags used by Hono’s components when reporting metrics have been changed. The common tag component has been renamed to component-type. The protocol tag formerly used by adapters to indicate the transport protocol that a message has been received over, has been replaced by the generic component-name tag which indicates the name of the component that a metric has been reported by. Please refer to the Metrics API for details. Note that these changes do not affect the legacy Graphite based metrics back end.

Deprecations

The Hono Messaging component is now deprecated and will be removed from Hono in version 0.9 altogether. The example deployment has not been using Hono Messaging since 0.6 and there is no practical reason for using it anymore.

0.9-M1

New Features

The default Micrometer back end is now Prometheus, the Grafana dash boards have been updated to retrieve data from Prometheus instead of the old InfluxDB. The Graphite based legacy metrics format can still be used but requires building Hono from source and activating the metrics-graphite Maven build profile. Please refer to the Monitoring admin guide for details.
The org.eclipse.hono.service.credentials.CompleteBaseCredentialsService class now supports the transparent on-the-fly hashing of clear text passwords contained in hashed-password credentials. Please refer to the Device Registry user guide for details.

Fixes & Enhancements

The base classes for implementing the Device Registration and Tenant APIs have been instrumented with OpenTracing. New variants of the RegistrationService.assertRegistration, TenantService.get and CredentialsService.get methods have been added which also accept an OpenTracing span as a parameter. The default implementations of these methods still default to the previously existing methods. In RegistrationService implementations based on BaseRegistrationService an OpenTracing span will be created, passed on to the assertRegistration method and finished eventually. The same applies to TenantService implementations based on BaseTenantService concerning the get method and to CredentialsService implementations based on BaseCredentialsService concerning the get method.

API Changes

The org.eclipse.hono.service.credentials.CompleteBaseCredentialsService class now requires an org.eclipse.hono.auth.HonoPasswordEncoder to be passed into its constructor. The org.eclipse.hono.auth.SpringBasedHonoPasswordEncoder has been added as a default implementation for this purpose.
The Tenant API now optionally allows specifying an X.509 certificate instead of a public key when defining a trusted CA.