v1.1.0 - Experimental Cluster Sharding Metrics

Experimental Cluster Sharding Metrics

Starting on this release we are introducing experimental support for Cluster Sharding, including the following metrics:

• akka.cluster.sharding.region.hosted-shards as a range sampler tracking the number of shards hosted in a region.
• akka.cluster.sharding.region.hosted-entitites as a histogram sampling the number of entities hosted in a region.
• akka.cluster.sharding.region.processed-messages as a counter tracking how many messages have been processed by the region actor.
• akka.cluster.sharding.shard.hosted-entities as a histogram sampling the number of entities hosted in each shard.
• akka.cluster.sharding.shard.processed-messages as a histogram sampling the number of messages processed by each shard.

All metrics will have the type=typeName tag with thetypeName parameter provided when starting the sharding. Additionally, the instrumentation will automatically create an actor group named shardedType/typeName and include all entity actors on it so that performance of the entity actors can be tracked as well.

The support is considered experimental because the number, names and type of metrics might be corrected in the future but if nothing important comes up in the next few weeks we will remove the experimental marker on the next release. Currently these metrics are only supported on Akka 2.5, we will backport support to Akka 2.4 when the experimental marker gets removed.

Contributors:

• @mladens and @ivantopo from Kamino contributed cluster sharding metrics via #16.