Hi I need some help to figure out the root cause of this error. I am running flink 1.3.2 on K8S.
My cluster has been up and running for almost two weeks and all of a sudden I see this familiar error again, my task manager is killed/lost. There are many ways cause this error, I need help to figure out what is the root cause this time. >From JM.log *2017-12-26 14:57:08,624* INFO org.apache.zookeeper.ClientCnxn - Client session timed out, have not heard from server in 85001ms for sessionid 0x25ddcdec0ef77af, closing socket connection and attempting reconnect 2017-12-26 14:57:23,621 WARN akka.remote.RemoteWatcher - Detected unreachable: [akka.tcp://flink@fps-flink-taskmanager-960711320-vx0hj:39249] 2017-12-26 14:57:23,623 INFO org.apache.flink.runtime.jobmanager.JobManager - Task manager akka.tcp://flink@fps-flink-taskmanager-960711320-vx0hj:39249/user/taskmanager terminated. 2017-12-26 14:57:23,624 INFO org.apache.flink.runtime.executiongraph.ExecutionGraph - Source: KafkaSource(maxwell.users) -> MaxwellFilter->Maxwell(maxwell.users) -> FixedDelayWatermark(maxwell.users) -> MaxwellFPSEvent->InfluxDBData(maxwell.users) -> Sink: influxdbSink(maxwell.users) (1/1) (ddca953ae90906daaae08791e1fde729) switched from RUNNING to FAILED. java.lang.Exception: TaskManager was lost/killed: e14186b8fd22699210273f887570a172 @ fps-flink-taskmanager-960711320-vx0hj (dataPort=37353) >From TM.log *2017-12-26 14:56:26,019 INFO* org.apache.flink.runtime.taskmanager.Task - Source: KafkaSource(maxwell.tickets) -> MaxwellFilter->Maxwell(maxwell.tickets) -> FixedDelayWatermark(maxwell.tickets) -> MaxwellFPSEvent->InfluxDBData(maxwell.tickets) -> Sink: influxdbSink(maxwell.tickets) (1/1) (44b4caf2010bb2b061b67d4f6c8dbc3f) switched from RUNNING to FAILED.java.lang.Exception: TaskManager akka://flink/user/taskmanager disconnects from JobManager akka.tcp://flink@fps-flink-jobmanager:6123/user/jobmanager: *Old JobManager lost its leadership.* Somehow TM detected JM leadership loss from ZK and self disconnected? And couple of seconds later, JM failed to connect to ZK? After all the cluster recovered nicely by its own, but I am wondering does this break the exactly-once semantics? If yes, what should I take care? Thanks team! Full log: https://gist.github.com/zenhao/e2f9b929f4eaee32f99948d462db7359
