CODEWITHSUNDEEP
scalaakkadistributed-computingakka-cluster
vaibhavatul47
vaibhavatul47

Reputation: 2885

Akka: Should seed node always be running for new nodes to join akka-cluster?

Steps to reproduce problem:

  1. Start Seed1 node (First seed mentioned in conf)
  2. Start another node(Node2). It will discover seed node and join cluster system. // Requests are served by both nodes.
  3. Now, Stop Seed1. // All Requests are served by Node2.
  4. Start another node(Node3). It will start but say that seed nodes are unreachable. // All requests are still served only by Node2. I assume because this node failed to join the cluster.
  5. Restart Seed1. // Logs show MemberUp logs for Seed1 and Node3, But // All requests are still served by Node2!

Upvotes: 0

Views: 428

Answers (1)

tkachuko
tkachuko

Reputation: 1986

According to documentation:

The seed nodes can be started in any order and it is not necessary to have all seed nodes running, but the node configured as the first element in the seed-nodes configuration list must be started when initially starting a cluster, otherwise the other seed-nodes will not become initialized and no other node can join the cluster. Once more than two seed nodes have been started it is no problem to shut down the first seed node. If the first seed node is restarted, it will first try to join the other seed nodes in the existing cluster.

Upvotes: 1

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