Configuring the Eclipse Amlen resource adapter for high availability when you use topics

When you want to set up Eclipse Amlen resource adapter in a highly available configuration, you must consider the values that are assigned to the following activation specification properties.

You can configure a clientId in this scenario. JMS allows only one connection per clientId. Set clientId so that only one WebSphere® Application Server can connect to Eclipse Amlen at a time. The connected WebSphere Application Server is the server that is processing messages.

Configure the Eclipse Amlen resource adapter properties

Activation specification configuration
Consider the settings of the following activation specification properties when you configure the Eclipse Amlen resource adapter to support high availability for inbound communication:
  • clientId
    The client ID for this connection.
    You might want to set a client ID so that you can restrict connections into Eclipse Amlen based on the client ID that is specified in the connection policy. Using a client ID ensures that only one WebSphere Application Server can connect at a time. You can also limit the actions that a connected client can perform based on the client ID that is specified in the messaging policy.
  • server
    A comma or space separated list of the two host names or IP addresses for the primary and the standby Eclipse Amlen servers. For example, 9.1.2.3,9.1.2.4.
  • port
    The port of the endpoint that you configured.
    If there are multiple Eclipse Amlen servers in the server properties list, then all servers use the same port.
  • concurrentConsumers
    The maximum number of consumers on this connection.
    You can tune the value of this parameter to enable multiple instances of the MDB to run in parallel to help to improve throughput.
  • clientMessageCache
    The maximum number of cached messages for each consumer.
    clientMessageCache allows Eclipse Amlen and the MDB to consume a number of messages at the same time. A higher setting increases throughput, but can result in uneven message distribution.
  • subscriptionDurability
    Specifies whether a topic subscription is durable.
    Set this value to Durable if you want published messages to be kept for processing even when WebSphere Application Server is not connected or your applications are stopped.
    Set this value to Nondurable if you want to process messages only while WebSphere Application Server is connected and your applications are running.
  • subscriptionName
    If you are using shared durable subscriptions, set the subscriptionName to the destination that is specified in the global-shared subscription messaging policy.
  • subscriptionShared
    Specifies whether a subscription is shared between consumers or not.
    Set this value to Shared to use the shared subscription capability and enable scaling within a WebSphere Application Server.
Specify one of the following options:
  • destination and destinationType
    destination specifies the name of the topic from which messages are received. destinationType specifies the type of destination.
    The value of destinationType must be set to javax.jms.Topic.
  • destinationLookup
    The name of a JNDI object that represents the Eclipse Amlen topic from which messages are received.