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Posted to issues@spark.apache.org by "Stavros Kontopoulos (JIRA)" <ji...@apache.org> on 2018/02/14 22:18:00 UTC
[jira] [Comment Edited] (SPARK-23423) Application declines any
offers when killed+active executors rich
spark.dynamicAllocation.maxExecutors
[ https://issues.apache.org/jira/browse/SPARK-23423?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16364861#comment-16364861 ]
Stavros Kontopoulos edited comment on SPARK-23423 at 2/14/18 10:17 PM:
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Hi [~igor.berman]. Looking at the code again I think when there is a status update tasksIds of dead tasks are removed:
[https://github.com/apache/spark/blob/master/resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala#L732]
Slaves are not removed but task Ids are, maybe something else is not working. Do you have a log at the time of the issue to attach?
The test you have is ok but I suspect it does not trigger deletion for the tasks in the case of a failure. I will check it.
Btw the behavior for checking the upper limit of the num of the executors you are referring to was added here: spark-16944.
was (Author: skonto):
Hi [~igor.berman]. Looking at the code again I think when there is a status update tasksIds of dead tasks are removed:
[https://github.com/apache/spark/blob/master/resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala#L732]
Slaves are not removed but task Ids are, maybe something else is not working. Do you have a log at the time of the issue to attach?
The test you have is ok but I suspect it does not trigger deletion for the tasks in the case of a failure. i will check it.
Btw the behavior for checking the upper limit of the num of the executors you are referring to was added here: spark-16944.
> Application declines any offers when killed+active executors rich spark.dynamicAllocation.maxExecutors
> ------------------------------------------------------------------------------------------------------
>
> Key: SPARK-23423
> URL: https://issues.apache.org/jira/browse/SPARK-23423
> Project: Spark
> Issue Type: Bug
> Components: Mesos, Spark Core
> Affects Versions: 2.2.1
> Reporter: Igor Berman
> Priority: Major
>
> Hi
> I've noticed rather strange behavior of MesosCoarseGrainedSchedulerBackend when running on Mesos with dynamic allocation on and limiting number of max executors by spark.dynamicAllocation.maxExecutors.
> Suppose we have long running driver that has cyclic pattern of resource consumption(with some idle times in between), due to dyn.allocation it receives offers and then releases them after current chunk of work processed.
> Since at [https://github.com/apache/spark/blob/master/resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala#L573] the backend compares numExecutors < executorLimit and
> numExecutors is defined as slaves.values.map(_.taskIDs.size).sum and slaves holds all slaves ever "met", i.e. both active and killed (see comment [https://github.com/apache/spark/blob/master/resource-managers/mesos/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala#L122)]
> On the other hand, number of taskIds should be updated due to statusUpdate, but suppose this update is lost(actually I don't see logs of 'is now TASK_KILLED') so this number of executors might be wrong
>
> I've created test that "reproduces" this behavior, not sure how good it is:
> {code:java}
> //MesosCoarseGrainedSchedulerBackendSuite
> test("max executors registered stops to accept offers when dynamic allocation enabled") {
> setBackend(Map(
> "spark.dynamicAllocation.maxExecutors" -> "1",
> "spark.dynamicAllocation.enabled" -> "true",
> "spark.dynamicAllocation.testing" -> "true"))
> backend.doRequestTotalExecutors(1)
> val (mem, cpu) = (backend.executorMemory(sc), 4)
> val offer1 = createOffer("o1", "s1", mem, cpu)
> backend.resourceOffers(driver, List(offer1).asJava)
> verifyTaskLaunched(driver, "o1")
> backend.doKillExecutors(List("0"))
> verify(driver, times(1)).killTask(createTaskId("0"))
> val offer2 = createOffer("o2", "s2", mem, cpu)
> backend.resourceOffers(driver, List(offer2).asJava)
> verify(driver, times(1)).declineOffer(offer2.getId)
> }{code}
>
>
> Workaround: Don't set maxExecutors with dynamicAllocation on
>
> Please advice
> Igor
> marking you friends since you were last to touch this piece of code and probably can advice something([~vanzin], [~skonto], [~susanxhuynh])
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