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Posted to yarn-issues@hadoop.apache.org by "Wangda Tan (Jira)" <ji...@apache.org> on 2020/10/20 05:33:00 UTC
[jira] [Commented] (YARN-10178) Global Scheduler asycthread crash
caused by 'Comparison method violates its general contract'
[ https://issues.apache.org/jira/browse/YARN-10178?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17217285#comment-17217285 ]
Wangda Tan commented on YARN-10178:
-----------------------------------
Since recently we have a customer has the same issue, I spent some time to look at this, thanks [~tuyu] for the detailed analysis.
Apart from issues mentioned by [~tuyu], which is async-scheduling related, I think it can also happen when async-scheduling is disabled.
A possible place is completedContainer, it doesn't hold scheduler's lock, so it can happen even though async-scheduling is disabled. (I checked the problematic log, there's a container release event happened at the exact same timestamp (within the same milli-second) when the RM crash happens.
One possible way to fix the problem is, inside PriorityUtilizationQueueOrderingPolicy, take a snapshot of queue capacities (which includes
AbsoluteUsedCapacity
UsedCapacity
ConfiguredMinResource
AbsoluteCapacity
)
Create a new internal class (like PriorityQueueResourcesForSorting) to include the 4 fields, instead of sorting the CSQueue directly, we will sort the new structure.
There're additional costs to copy the resources field, but it should be minimum for most cases (unless you have thousands of queues). cc: [~bteke]
> Global Scheduler asycthread crash caused by 'Comparison method violates its general contract'
> ---------------------------------------------------------------------------------------------
>
> Key: YARN-10178
> URL: https://issues.apache.org/jira/browse/YARN-10178
> Project: Hadoop YARN
> Issue Type: Bug
> Components: capacity scheduler
> Affects Versions: 3.2.1
> Reporter: tuyu
> Priority: Major
>
> Global Scheduler Async Thread crash stack
> {code:java}
> ERROR org.apache.hadoop.yarn.server.resourcemanager.ResourceManager: Received RMFatalEvent of type CRITICAL_THREAD_CRASH, caused by a critical thread, Thread-6066574, that exited unexpectedly: java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.util.TimSort.mergeHi(TimSort.java:899)
> at java.util.TimSort.mergeAt(TimSort.java:516)
> at java.util.TimSort.mergeForceCollapse(TimSort.java:457)
> at java.util.TimSort.sort(TimSort.java:254)
> at java.util.Arrays.sort(Arrays.java:1512)
> at java.util.ArrayList.sort(ArrayList.java:1462)
> at java.util.Collections.sort(Collections.java:177)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.policy.PriorityUtilizationQueueOrderingPolicy.getAssignmentIterator(PriorityUtilizationQueueOrderingPolicy.java:221)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.ParentQueue.sortAndGetChildrenAllocationIterator(ParentQueue.java:777)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.ParentQueue.assignContainersToChildQueues(ParentQueue.java:791)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.ParentQueue.assignContainers(ParentQueue.java:623)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.allocateOrReserveNewContainers(CapacityScheduler.java:1635)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.allocateContainerOnSingleNode(CapacityScheduler.java:1629)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.allocateContainersToNode(CapacityScheduler.java:1732)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.allocateContainersToNode(CapacityScheduler.java:1481)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.schedule(CapacityScheduler.java:569)
> at org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler$AsyncScheduleThread.run(CapacityScheduler.java:616)
> {code}
> JAVA 8 Arrays.sort default use timsort algo, and timsort has few require
> {code:java}
> 1.x.compareTo(y) != y.compareTo(x)
> 2.x>y,y>z --> x > z
> 3.x=y, x.compareTo(z) == y.compareTo(z)
> {code}
> if not Arrays paramters not satify this require,TimSort will throw 'java.lang.IllegalArgumentException'
> look at PriorityUtilizationQueueOrderingPolicy.compare function,we will know Capacity Scheduler use this these queue resource usage to compare
> {code:java}
> AbsoluteUsedCapacity
> UsedCapacity
> ConfiguredMinResource
> AbsoluteCapacity
> {code}
> In Capacity Scheduler Global Scheduler AsyncThread use PriorityUtilizationQueueOrderingPolicy function to choose queue to assign container,and construct a CSAssignment struct, and use submitResourceCommitRequest function add CSAssignment to backlogs
> ResourceCommitterService will tryCommit this CSAssignment,look tryCommit function,there will update queue resource usage
> {code:java}
> public boolean tryCommit(Resource cluster, ResourceCommitRequest r,
> boolean updatePending) {
> long commitStart = System.nanoTime();
> ResourceCommitRequest<FiCaSchedulerApp, FiCaSchedulerNode> request =
> (ResourceCommitRequest<FiCaSchedulerApp, FiCaSchedulerNode>) r;
>
> ...
> boolean isSuccess = false;
> if (attemptId != null) {
> FiCaSchedulerApp app = getApplicationAttempt(attemptId);
> // Required sanity check for attemptId - when async-scheduling enabled,
> // proposal might be outdated if AM failover just finished
> // and proposal queue was not be consumed in time
> if (app != null && attemptId.equals(app.getApplicationAttemptId())) {
> if (app.accept(cluster, request, updatePending)
> && app.apply(cluster, request, updatePending)) { // apply this resource
> ...
> }
> }
> }
> return isSuccess;
> }
> }
> {code}
> {code:java}
> public boolean apply(Resource cluster, ResourceCommitRequest<FiCaSchedulerApp,
> FiCaSchedulerNode> request, boolean updatePending) {
> ...
> if (!reReservation) {
> getCSLeafQueue().apply(cluster, request);
> }
> ...
> }
> {code}
> LeafQueue.apply invok allocateResource
> {code:java}
> void allocateResource(Resource clusterResource,
> Resource resource, String nodePartition) {
> try {
> writeLock.lock(); // only lock leaf queue lock
> queueUsage.incUsed(nodePartition, resource);
>
> ++numContainers;
>
> CSQueueUtils.updateQueueStatistics(resourceCalculator, clusterResource,
> this, labelManager, nodePartition); // there will update queue statistics
> } finally {
> writeLock.unlock();
> }
> }
> {code}
> we found ResourceCommitterService will only lock leaf queue to update queue statistics, but AsyncThread use sortAndGetChildrenAllocationIterator only lock queue root queue lock
> {code:java}
> ParentQueue.java
> private Iterator<CSQueue> sortAndGetChildrenAllocationIterator(
> String partition) {
> try {
> readLock.lock();
> return queueOrderingPolicy.getAssignmentIterator(partition);
> } finally {
> readLock.unlock();
> }
> }
> {code}
> so if multi async thread compare queue usage statistics and ResourceCommitterService apply leaf queue change statistics concurrent, will break TimSort algo required, and cause thread crash
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