(DEPRECATED) Apache Flink User Mailing List archive.

Re: Standalone cluster instability

Posted by Shailesh Jain on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Standalone-cluster-instability-tp19091p22352.html

Thank you for your help Piotrek.

I think it was a combination of a. other processes taking up available memory and b. flink processes consuming all the memory allocated to them, that resulted in kernel running out of memory.

Are there any heuristics or best practices which you (or anyone in the community) recommend to benchmark memory requirements of a particular flink job?

Thanks,

Shailesh

On Tue, Aug 14, 2018 at 6:08 PM, Piotr Nowojski <[hidden email]> wrote:

Hi,

Good that we are more or less on track with this problem :) But the problem here is not that heap size is too small, bot that your kernel is running out of memory and starts killing processes. Either:

1. some other process is using the available memory
2. Increase memory allocation on your machine/virtual machine/container/cgroup
3. Decrease the heap size of Flink’s JVM or non heap size (decrease network memory buffer pool). Of course for any given job/state size/configuration/cluster size there is some minimal reasonable memory size that you have to assign to Flink, otherwise you will have poor performance and/or constant garbage collections and/or you will start getting OOM errors from JVM (don’t confuse those with OS/kernel's OOM errors - those two are on a different level).

Piotrek

On 14 Aug 2018, at 07:36, Shailesh Jain <[hidden email]> wrote:

Hi Piotrek,

Thanks for your reply. I checked through the syslogs for that time, and I see this:

Aug 8 13:20:52 smoketest kernel: [1786160.856662] Out of memory: Kill process 2305 (java) score 468 or sacrifice child
Aug 8 13:20:52 smoketest kernel: [1786160.859091] Killed process 2305 (java) total-vm:6120624kB, anon-rss:3661216kB, file-rss:16676kB

As you pointed out, kernel killed the task manager process.

If I had already set the max heap size for the JVM (to 3GB in this case), and the memory usage stats showed 2329MB being used 90 seconds earlier, it seems a bit unlikely for operators to consume 700 MB heap space in that short time, because our events ingestion rate is not that high (close to 10 events per minute).

2018-08-08 13:19:23,341 INFO org.apache.flink.runtime.taskmanager.TaskManager              - Memory usage stats: [HEAP: 2329/3072/3072 MB, NON HEAP: 154/197/-1 MB (used/committed/max)]

Is it possible to log individual operator's memory consumption? This would help in narrowing down on the root cause. There were around 50 operators running (~8 kafka source/sink, ~8 Window operators, and the rest CEP operators).

Thanks,
Shailesh

On Fri, Aug 10, 2018 at 4:48 PM, Piotr Nowojski <[hidden email]> wrote:
Hi,

Please post full TaskManager logs, including stderr and stdout. (Have you checked the stderr/stdout for some messages?)

I could think of couple reasons:
1. process segfault
2. process killed by OS
3. OS failure

1. Should be visible by some message in stderr/stdout file and can be caused by for example JVM, RocksDB or some other native library/code bug.
2. Is your system maybe running out of memory? Kernel might kill process if that’s happening. You can also check system (linux?) logs for errors that correlate in time. Where are those logs depend on your OS.
3. This might be tricky, but I have seen kernel failures that prevented any messages from being logged for example. Besides this TaskManager failure is your machine operating normally without any other problems/crashes/restarts?

Piotrek

On 10 Aug 2018, at 06:59, Shailesh Jain <[hidden email]> wrote:

Hi,

I hit a similar issue yesterday, the task manager died suspiciously, no error logs in the task manager logs, but I see the following exceptions in the job manager logs:

2018-08-05 18:03:28,322 ERROR akka.remote.Remoting                                          - Association to [akka.tcp://flink@localhost:34483] with UID [328996232] irrecoverably failed. Quarantining address.
java.util.concurrent.TimeoutException: Remote system has been silent for too long. (more than 48.0 hours)
        at akka.remote.ReliableDeliverySupervisor$$anonfun$idle$1.applyOrElse(Endpoint.scala:375)
        at akka.actor.Actor$class.aroundReceive(Actor.scala:502)
        at akka.remote.ReliableDeliverySupervisor.aroundReceive(Endpoint.scala:203)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
        at akka.actor.ActorCell.invoke(ActorCell.scala:495)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
        at akka.dispatch.Mailbox.run(Mailbox.scala:224)
        at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

but almost 3 days later it hit this:

2018-08-08 13:22:00,061 INFO org.apache.flink.runtime.executiongraph.ExecutionGraph        - Job Internal state machine job (1057c13d169dae609466210174e2cc8b) switched from state RUNNING to FAILING.
java.lang.Exception: TaskManager was lost/killed: 5ee5de1112776c404541743b63ae0fe0 @ localhost (dataPort=44997)
        at org.apache.flink.runtime.instance.SimpleSlot.releaseSlot(SimpleSlot.java:217)
        at org.apache.flink.runtime.instance.SlotSharingGroupAssignment.releaseSharedSlot(SlotSharingGroupAssignment.java:523)
        at org.apache.flink.runtime.instance.SharedSlot.releaseSlot(SharedSlot.java:192)
        at org.apache.flink.runtime.instance.Instance.markDead(Instance.java:167)
        at org.apache.flink.runtime.instance.InstanceManager.unregisterTaskManager(InstanceManager.java:212)
        at org.apache.flink.runtime.jobmanager.JobManager.org$apache$flink$runtime$jobmanager$JobManager$$handleTaskManagerTerminated(JobManager.scala:1198)
        at org.apache.flink.runtime.jobmanager.JobManager$$anonfun$handleMessage$1.applyOrElse(JobManager.scala:1096)
        at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
        at org.apache.flink.runtime.LeaderSessionMessageFilter$$anonfun$receive$1.applyOrElse(LeaderSessionMessageFilter.scala:49)
        at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
        at org.apache.flink.runtime.LogMessages$$anon$1.apply(LogMessages.scala:33)
        at org.apache.flink.runtime.LogMessages$$anon$1.apply(LogMessages.scala:28)
        at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123)
        at org.apache.flink.runtime.LogMessages$$anon$1.applyOrElse(LogMessages.scala:28)
        at akka.actor.Actor$class.aroundReceive(Actor.scala:502)
        at org.apache.flink.runtime.jobmanager.JobManager.aroundReceive(JobManager.scala:122)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
        at akka.actor.dungeon.DeathWatch$class.receivedTerminated(DeathWatch.scala:46)
        at akka.actor.ActorCell.receivedTerminated(ActorCell.scala:374)
        at akka.actor.ActorCell.autoReceiveMessage(ActorCell.scala:511)
        at akka.actor.ActorCell.invoke(ActorCell.scala:494)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
        at akka.dispatch.Mailbox.run(Mailbox.scala:224)
        at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

followed by:

2018-08-08 13:22:20,090 INFO org.apache.flink.runtime.executiongraph.ExecutionGraph        - Job Internal state machine job (1057c13d169dae609466210174e2cc8b) switched from state RUNNING to FAILING.
org.apache.flink.runtime.jobmanager.scheduler.NoResourceAvailableException: Not enough free slots available to run the job. You can decrease the operator parallelism or increase the number of slots per TaskManager in the configuration. Task to schedule: < Attempt #2 (Source: Custom Source -> Filter (1/1)) @ (unassigned) - [SCHEDULED] > with groupID < fbd084243e87c3fdf3c709a0f2eecfd7 > in sharing group < SlotSharingGroup [fa00013ef15454ea93d21e8c346e0dd4, fbd084243e87c3fdf3c709a0f2eecfd7, 8f5517c035f67da702f459ef5f3b849f] >. Resources available to scheduler: Number of instances=0, total number of slots=0, available slots=0
        at org.apache.flink.runtime.jobmanager.scheduler.Scheduler.scheduleTask(Scheduler.java:263)
        at org.apache.flink.runtime.jobmanager.scheduler.Scheduler.allocateSlot(Scheduler.java:142)
        at org.apache.flink.runtime.executiongraph.Execution.lambda$allocateAndAssignSlotForExecution$1(Execution.java:440)
        at java.util.concurrent.CompletableFuture.uniComposeStage(CompletableFuture.java:981)
        at java.util.concurrent.CompletableFuture.thenCompose(CompletableFuture.java:2124)
        at org.apache.flink.runtime.executiongraph.Execution.allocateAndAssignSlotForExecution(Execution.java:438)
        at org.apache.flink.runtime.executiongraph.ExecutionJobVertex.allocateResourcesForAll(ExecutionJobVertex.java:503)
        at org.apache.flink.runtime.executiongraph.ExecutionGraph.scheduleEager(ExecutionGraph.java:900)
        at org.apache.flink.runtime.executiongraph.ExecutionGraph.scheduleForExecution(ExecutionGraph.java:854)
        at org.apache.flink.runtime.executiongraph.ExecutionGraph.restart(ExecutionGraph.java:1175)
        at org.apache.flink.runtime.executiongraph.restart.ExecutionGraphRestartCallback.triggerFullRecovery(ExecutionGraphRestartCallback.java:59)
        at org.apache.flink.runtime.executiongraph.restart.FixedDelayRestartStrategy$1.run(FixedDelayRestartStrategy.java:68)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

There are no error logs in task manager, and following is the last memory consumption log by task manager:

2018-08-08 13:19:23,341 INFO org.apache.flink.runtime.taskmanager.TaskManager              - Memory usage stats: [HEAP: 2329/3072/3072 MB, NON HEAP: 154/197/-1 MB (used/committed/max)]
2018-08-08 13:19:23,341 INFO org.apache.flink.runtime.taskmanager.TaskManager              - Direct memory stats: Count: 115, Total Capacity: 38101792, Used Memory: 38101793
2018-08-08 13:19:23,341 INFO org.apache.flink.runtime.taskmanager.TaskManager              - Off-heap pool stats: [Code Cache: 52/55/240 MB (used/committed/max)], [Metaspace: 90/125/-1 MB (used/committed/max)], [Compressed Class Space: 11/17/1024 MB (used/committed/max)]
2018-08-08 13:19:23,341 INFO org.apache.flink.runtime.taskmanager.TaskManager              - Garbage collector stats: [G1 Young Generation, GC TIME (ms): 300736, GC COUNT: 6574], [G1 Old Generation, GC TIME (ms): 152, GC COUNT: 2]

So I think it rules out OOM as a cause for this crash.

Any ideas/leads to debug this would be really helpful. The cluster is running on version 1.4.2.

Thanks,
Shailesh

On Mon, Mar 26, 2018 at 4:18 PM, Alexander Smirnov <[hidden email]> wrote:
Hi Piotr,

I didn't find anything special in the logs before the failure.
Here are the logs, please take a look:

https://drive.google.com/drive/folders/1zlUDMpbO9xZjjJzf28lUX-bkn_x7QV59?usp=sharing

The configuration is:

3 task managers:
qafdsflinkw011.scl
qafdsflinkw012.scl
qafdsflinkw013.scl - lost connection

3 job managers:
qafdsflinkm011.scl - the leader
qafdsflinkm012.scl
qafdsflinkm013.scl

3 zookeepers:
qafdsflinkzk011.scl
qafdsflinkzk012.scl
qafdsflinkzk013.scl

Thank you,
Alex

On Wed, Mar 21, 2018 at 6:23 PM Piotr Nowojski <[hidden email]> wrote:
Hi,

Does the issue really happen after 48 hours?
Is there some indication of a failure in TaskManager log?

If you will be still unable to solve the problem, please provide full TaskManager and JobManager logs.

Piotrek

On 21 Mar 2018, at 16:00, Alexander Smirnov <[hidden email]> wrote:

One more question - I see a lot of line like the following in the logs

[2018-03-21 00:30:35,975] ERROR Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:35320] with UID [1500204560] irrecoverably failed. Quarantining address. (akka.remote.Remoting)
[2018-03-21 00:34:15,208] WARN Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:41068] with unknown UID is irrecoverably failed. Address cannot be quarantined without knowing the UID, gating instead for 5000 ms. (akka.remote.Remoting)
[2018-03-21 00:34:15,235] WARN Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:40677] with unknown UID is irrecoverably failed. Address cannot be quarantined without knowing the UID, gating instead for 5000 ms. (akka.remote.Remoting)
[2018-03-21 00:34:15,256] WARN Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:40382] with unknown UID is irrecoverably failed. Address cannot be quarantined without knowing the UID, gating instead for 5000 ms. (akka.remote.Remoting)
[2018-03-21 00:34:15,256] WARN Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:44744] with unknown UID is irrecoverably failed. Address cannot be quarantined without knowing the UID, gating instead for 5000 ms. (akka.remote.Remoting)
[2018-03-21 00:34:15,266] WARN Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:42413] with unknown UID is irrecoverably failed. Address cannot be quarantined without knowing the UID, gating instead for 5000 ms. (akka.remote.Remoting)

The host is available, but I don't understand where port number comes from. Task Manager uses another port (which is printed in logs on startup)
Could you please help to understand why it happens?

Thank you,
Alex

On Wed, Mar 21, 2018 at 4:19 PM Alexander Smirnov <[hidden email]> wrote:
Hello,

I've assembled a standalone cluster of 3 task managers and 3 job managers(and 3 ZK) following the instructions at

https://ci.apache.org/projects/flink/flink-docs-release-1.4/ops/deployment/cluster_setup.html and https://ci.apache.org/projects/flink/flink-docs-release-1.4/ops/jobmanager_high_availability.html

It works ok, but randomly, task managers becomes unavailable. JobManager has exception like below in logs:

[2018-03-19 00:33:10,211] WARN Association with remote system [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:42413] has failed, address is now gated for [5000] ms. Reason: [Association failed with [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:42413]] Caused by: [Connection refused: qafdsflinkw811.nn.five9lab.com/10.5.61.124:42413] (akka.remote.ReliableDeliverySupervisor)
[2018-03-21 00:30:35,975] ERROR Association to [akka.tcp://flink@qafdsflinkw811.nn.five9lab.com:35320] with UID [1500204560] irrecoverably failed. Quarantining address. (akka.remote.Remoting)
java.util.concurrent.TimeoutException: Remote system has been silent for too long. (more than 48.0 hours)
at akka.remote.ReliableDeliverySupervisor$$anonfun$idle$1.applyOrElse(Endpoint.scala:375)
at akka.actor.Actor$class.aroundReceive(Actor.scala:502)
at akka.remote.ReliableDeliverySupervisor.aroundReceive(Endpoint.scala:203)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
at akka.actor.ActorCell.invoke(ActorCell.scala:495)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
at akka.dispatch.Mailbox.run(Mailbox.scala:224)
at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

I can't find a reason for this exception, any ideas?

Thank you,
Alex