We are using Nitrogen-SR3 version of Opendaylight. We want to support more NEs, and during our testing observed "Shards" missing. While analyzing this issue we noticed Shards are missing as LevelDB is not acknowledging the writes as it is very busy. We came across Cassandra plugin for "Akka" persistence, will it be a good idea to use Cassandra instead of LevelDB so that we can scale better.
Please advice us whether there are any production deployment with Cassandra plugin for Akka persistence.
Of course you can use whatever plugin suits your environment and needs. I'm not aware of anyone using Cassandra. LevelDB is suitable as a default as it's simple and doesn't require any external server. It seems to work fine for most use cases even though akka doesn't recommend it for production.
I assume you're probably hitting the (dreaded) circuit-breaker timeout in akka when the plugin response isn't timely which can happen with a slow disk or saturation. The default timeout is 5 sec but is configurable (check the akka persistence docs).
