I am using Confluent 4 for kafka and zookeeper installation.
On our Kafka Cluster environment (of 3 brokers and 3 zookeeper nodes running on 3 aws instances) we are seeing a set of below warnings, repeatedly getting recorded in the broker's server.log file.
We have not observed any functionality issues due to this yet, but we are not able to find the root cause and there may be a chance in future it will affect the clients or other broker nodes. We are not sure yet about this. Below is the set of warnings
[2018-04-03 12:00:40,707] WARN Interrupted while waiting for message on queue (org.apache.zookeeper.server.quorum.QuorumCnxManager)
java.lang.InterruptedException
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:2014)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2088)
at java.util.concurrent.ArrayBlockingQueue.poll(ArrayBlockingQueue.java:418)
at org.apache.zookeeper.server.quorum.QuorumCnxManager.pollSendQueue(QuorumCnxManager.java:1097)
at org.apache.zookeeper.server.quorum.QuorumCnxManager.access$700(QuorumCnxManager.java:74)
at org.apache.zookeeper.server.quorum.QuorumCnxManager$SendWorker.run(QuorumCnxManager.java:932)
[2018-04-03 12:00:40,707] WARN Connection broken for id 1, my id = 3, error = (org.apache.zookeeper.server.quorum.QuorumCnxManager)
java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:171)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read(BufferedInputStream.java:265)
at java.io.DataInputStream.readInt(DataInputStream.java:387)
at org.apache.zookeeper.server.quorum.QuorumCnxManager$RecvWorker.run(QuorumCnxManager.java:1013)
[2018-04-03 12:00:40,708] WARN Interrupting SendWorker (org.apache.zookeeper.server.quorum.QuorumCnxManager)
[2018-04-03 12:00:40,707] WARN Send worker leaving thread (org.apache.zookeeper.server.quorum.QuorumCnxManager)
This set of warnings get repeated and getting observed in all 3 kafka nodes.
If anyone has any idea about why this warning gets generate, then please let me know.
Thanks in advance.