Caching

Development Environments

For all development purposes, we use a local memory-based cache Caffeine Cache which is automatically created during the server startup. And when the service stops, all data in the local cache will be automatically cleared.

Caffeine Cache is only for development environments

The Caffeine Cache is purely for development and test purposes only and must be avoided for production installation of xpanse.

Production Environments

For production environments, we use a distributed cache. The below distributed caches are at the moment fully supported. By support, we mean configurations for the cache added and also all functionalities tested.

Redis Cache

At the moment, this is the only distributed cache that's fully supported. To use Redis as the cache manager for xpanse, it must be activated by starting the application with profile redis and by replacing the placeholders for redis host, port and password as below.

java -jar xpanse-runtime-*-SNAPSHOT.jar \
          -Dspring.profiles.active=redis \
          -Dspring.data.redis.host=${redis-host} \
          -Dspring.data.redis.port=${redis-port} \
          -Dspring.data.redis.password=${redis-password}

Versions Supported

Current supported version of Redis is 7.4.2. This is the latest LTS release of Redis.

Default Configuration

The default configuration parameters for redis profile can be found

here

.

Overriding Default Configuration

We can override the above three default configurations by starting the application as below by replacing the placeholders with actual values.

java -jar xpanse-runtime-*-SNAPSHOT.jar \
          -Dspring.profiles.active=redis \
          -Dspring.data.redis.host=${replace-with-redis-host} \
          -Dspring.data.redis.port=${replace-with-redis-port} \
          -Dspring.data.redis.password=${replace-with-redis-password}

secrets better as environment variables

It's safe to provide the redis-related properties as environment variables rather than passing them directly in the command line. In case of this, the same property name must be set in UPPERCASE and underscore separated instead of dot for all variables.

network between xpanse and its redis

Using this startup command, the redis can run on any machine that's reachable from the xpanse runtime application.

Redis as a Docker Container

Redis offers official Docker images for running a database as a container. More details can be found here on the official page of Redis website here and on DockerHub here.

Starting new container

While starting the Redis docker container for the first time, we can configure redis-port, and redis-password as below and the same can be used in starting the xpanse runtime using the command described

above.

docker pull redis:7.4.2

By starting the container with the below command, the redis is started by automatically configuring the redis with xpanse redis port and password.

docker run --name ${container-name} \
            -e REDIS_PASSWORD=${replace-with-redis-password}
            -p <replace-with-redis-port>:6379 -d redis:7.4.2

Avoid secrets in command line

To avoid passing database related properties in command line, we can use the --env-file option of the docker run command to store all sensitive data.

Cached Data

The application will cache multiple types of data. Each type of data cache will be registered into a cache manager with a specific name and configuration. There are two types of cache managers, one is for Caffeine Cache and the other is for Redis Cache.

Cache manager for Caffeine defined in the class CaffeineCacheConfig

here

Cache manager for Redis defined in the class RedisCacheConfig

here

In both cache managers, the following caches are created with the following names:

REGION_AZS_CACHE_NAME -- to cache different available zones of the regions in the service cloud providers. SERVICE_FLAVOR_PRICE_CACHE_NAME -- to cache different prices of the flavors of the service with different billing models in the service cloud providers. CREDENTIAL_CACHE_NAME -- to cache different credentials the service cloud providers provided by the users. MONITOR_METRICS_CACHE_NAME --to cache different monitor metrics of the deployed services. DEPLOYER_VERSIONS_CACHE_NAME --to cache available versions of the deployer tools, such as terraform, opentofu etc.