akka sharding proxy cannot contact with coordinator

Question

I'm building an app with two kind of nodes (front and back) on akka 2.5.1, I'm using akka sharding for load and data distribution across the back nodes. The front node uses a shard proxy to send messages to the back. Shards initialisation is as follow:

  val renditionManager: ActorRef =
if(nodeRole == "back")
  clusterSharding.start(
    typeName = "Rendition",
    entityProps = Manger.props,
    settings = ClusterShardingSettings(system),
    extractEntityId = Manager.idExtractor,
    extractShardId = Manager.shardResolver)
else
  clusterSharding.startProxy(
    typeName = "Rendition",
    role = None,
    extractEntityId = Manager.idExtractor,
    extractShardId = Manager.shardResolver)

And i got some dead letters logs (omit most of the entries for brevity):

[info] [INFO] [06/02/2017 11:39:13.770] [wws-renditions-akka.actor.default-dispatcher-26] [akka://wws-renditions/system/sharding/RenditionCoordinator/singleton/coordinator] Message [akka.cluster.sharding.ShardCoordinator$Internal$Register] from Actor[akka.tcp://wws-renditions@127.0.0.1:2552/system/sharding/Rendition#1607279929] to Actor[akka://wws-renditions/system/sharding/RenditionCoordinator/singleton/coordinator] was not delivered. [8] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[info] [INFO] [06/02/2017 11:39:15.607] [wws-renditions-akka.actor.default-dispatcher-21] [akka://wws-renditions/system/sharding/RenditionCoordinator/singleton/coordinator] Message [akka.cluster.sharding.ShardCoordinator$Internal$RegisterProxy] from Actor[akka://wws-renditions/system/sharding/Rendition#-267271026] to Actor[akka://wws-renditions/system/sharding/RenditionCoordinator/singleton/coordinator] was not delivered. [9] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[info] [INFO] [06/02/2017 11:39:15.762] [wws-renditions-akka.actor.default-dispatcher-21] [akka://wws-renditions/system/sharding/replicator] Message [akka.cluster.ddata.Replicator$Internal$Status] from Actor[akka.tcp://wws-renditions@127.0.0.1:2552/system/sharding/replicator#-126233532] to Actor[akka://wws-renditions/system/sharding/replicator] was not delivered. [10] dead letters encountered, no more dead letters will be logged. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

and if i tried to use the proxy it fails to deliver and shows:

[info] [WARN] [06/02/2017 12:12:28.047] [wws-renditions-akka.actor.default-dispatcher-15] [akka.tcp://wws-renditions@127.0.0.1:2551/system/sharding/Rendition] Retry request for shard [51] homes from coordinator at [Actor[akka.tcp://wws-renditions@127.0.0.1:2552/system/sharding/RenditionCoordinator/singleton/coordinator#-1550443839]]. [1] buffered messages.

In the other hand, if I start a non-proxy shard in both nodes (front and back) it works properly.

Any advise? Thanks.

UPDATE

I finally figure it out why it was trying to connect to shards in wrong nodes. If it is only intended to start a shard in a single kind of node it is needed to add the following configuration

akka.cluster.sharding {
  role = "yourRole"
}

This way, akka sharding only will lookup on nodes tagged with role "yourRole"

Proxy is still not able to connect with shard coordinator and deliver messages to shards and got the following log trace:

[WARN] [06/06/2017 12:09:25.754] [cluster-nodes-akka.actor.default-dispatcher-16] [akka.tcp://cluster-nodes@127.0.0.1:2551/system/sharding/Manager] Retry request for shard [52] homes from coordinator at [Actor[akka.tcp://cluster-nodes@127.0.0.1:2552/system/sharding/ManagerCoordinator/singleton/coordinator#-2111378619]]. [1] buffered messages.

so help would be nice :)

akka sharding proxy cannot contact with coordinator

1 Answers