In Flink 1.1.3 on emr-5.2.0, I've experienced a particular problem twice and
I'm wondering if anyone has some insight about it.
In both cases, we deployed a job that fails very frequently (within 15s-1m of
launch). Eventually, the Flink cluster dies.
The sequence of events looks something like this:
* bad job is launched
* bad job fails & is restarted many times (I didn't have the "failure-rate"
restart strategy configuration right)
* Task manager logs: org.apache.flink.yarn.YarnTaskManagerRunner (SIGTERM
handler): RECEIVED SIGNAL 15: SIGTERM. Shutting down as requested.
* At this point, the YARN resource manager also logs the container failure
* More logs: Container
ResourceID{resourceId='container_1481658997383_0003_01_000013'} failed. Exit
status: Pmem limit exceeded (-104)
*
Diagnostics for container
ResourceID{resourceId='container_1481658997383_0003_01_000013'} in state
COMPLETE : exitStatus=Pmem limit exceeded (-104) diagnostics=Container
[pid=21246,containerID=container_1481658997383_0003_01_000013] is running
beyond physical memory limits. Current usage: 5.6 GB of 5.6 GB physical memory
used; 9.6 GB of 28.1 GB virtual memory used. Killing container.
Container killed on request. Exit code is 143
Container exited with a non-zero exit code 143
Total number of failed containers so far: 12
Stopping YARN session because the number of failed containers (12) exceeded the
maximum failed containers (11). This number is controlled by the
'yarn.maximum-failed-containers' configuration setting. By default its the
number of requested containers.
* From here onward, the logs repeatedly show that jobs fail to restart due
to "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 #68 (Source: …) @ (unassigned) -
[SCHEDULED] > with groupID < 73191c171abfff61fb5102c161274145 > in sharing
group < SlotSharingGroup [73191c171abfff61fb5102c161274145,
19596f7834805c8409c419f0edab1f1b] >. Resources available to scheduler: Number
of instances=0, total number of slots=0, available slots=0"
* Eventually, Flink stops for some reason (with another SIGTERM message),
presumably because of YARN
Does anyone have an idea why a bad job repeatedly failing would eventually
result in the Flink cluster dying?
Any idea why I'd get "Pmem limit exceeded" or "Not enough free slots available
to run the job"? The JVM heap usage and the free memory on the machines both
look reasonable in my monitoring dashboards. Could it possibly be a memory leak
due to classloading or something?
Thanks for any help or suggestions you can provide! I am hoping that the
"failure-rate" restart strategy will help avoid this issue in the future, but
I'd also like to understand what's making the cluster die so that I can prevent
it.
-Shannon
