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ASF subversion and git services commented on SOLR-6631: ------------------------------------------------------- Commit 1635576 from [~thelabdude] in branch 'dev/branches/branch_5x' [ https://svn.apache.org/r1635576 ] SOLR-6631: Part deux - refactor LatchChildWatcher to LatchWatcher that takes an optional EventType during construction to only release the latch when a specific event type is received. > DistributedQueue spinning on calling zookeeper getChildren() > ------------------------------------------------------------ > > Key: SOLR-6631 > URL: https://issues.apache.org/jira/browse/SOLR-6631 > Project: Solr > Issue Type: Bug > Components: SolrCloud > Reporter: Jessica Cheng Mallet > Assignee: Timothy Potter > Labels: solrcloud > Attachments: SOLR-6631.patch, SOLR-6631.patch > > > The change from SOLR-6336 introduced a bug where now I'm stuck in a loop > making getChildren() request to zookeeper with this thread dump: > {quote} > Thread-51 [WAITING] CPU time: 1d 15h 0m 57s > java.lang.Object.wait() > org.apache.zookeeper.ClientCnxn.submitRequest(RequestHeader, Record, Record, > ZooKeeper$WatchRegistration) > org.apache.zookeeper.ZooKeeper.getChildren(String, Watcher) > org.apache.solr.common.cloud.SolrZkClient$6.execute()<2 recursive calls> > org.apache.solr.common.cloud.ZkCmdExecutor.retryOperation(ZkOperation) > org.apache.solr.common.cloud.SolrZkClient.getChildren(String, Watcher, > boolean) > org.apache.solr.cloud.DistributedQueue.orderedChildren(Watcher) > org.apache.solr.cloud.DistributedQueue.getChildren(long) > org.apache.solr.cloud.DistributedQueue.peek(long) > org.apache.solr.cloud.DistributedQueue.peek(boolean) > org.apache.solr.cloud.Overseer$ClusterStateUpdater.run() > java.lang.Thread.run() > {quote} > Looking at the code, I think the issue is that LatchChildWatcher#process > always sets the event to its member variable event, regardless of its type, > but the problem is that once the member event is set, the await no longer > waits. In this state, the while loop in getChildren(long), when called with > wait being Integer.MAX_VALUE will loop back, NOT wait at await because event > != null, but then it still will not get any children. > {quote} > while (true) \{ > if (!children.isEmpty()) break; > watcher.await(wait == Long.MAX_VALUE ? DEFAULT_TIMEOUT : wait); > if (watcher.getWatchedEvent() != null) > \{ children = orderedChildren(null); \} > if (wait != Long.MAX_VALUE) break; > \} > {quote} > I think the fix would be to only set the event in the watcher if the type is > not None. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org