We have some issues with our druid console :
Unknown exception / …common.IOE : No known server exception
In middlemanager logs, we have :
WARN [WorkerTaskManager-CompletedTasksCleaner] org.apache.druid.indexing.worker.WorkerTaskManager - Exception while getting active tasks from overlord. will retry on next scheduled run.
org.apache.druid.java.util.common.IOE: No known server
On overlord logs :
org.apache.druid.indexing.seekablestream.supervisor.SeekableStreamSupervisor - Failed to get task runner because I’m not the leader!
On zookeeper :
2021-12-16 09:37:09,027 [myid:1] - WARN [NIOWorkerThread-2:NIOServerCnxn@366] - Unable to read additional data from client sessionid 0x1016c1d6ca8000c, likely client has closed socket
2021-12-16 09:37:37,619 [myid:1] - INFO [SessionTracker:ZooKeeperServer@413] - Expiring session 0x1016c1d6ca8000c, timeout of 30000ms exceeded
I don’t if all these errors are linked and how can I investigate more to find root cause(s) and solve issue(s) ?