[JIRA] (JENKINS-59793) Possible thread leak 'QueueSubTaskMetrics' in metrics

[manuelramonleonjime...@gmail.com (JIRA)]

Title: Message Title

Ramon Leon created an issue   Jenkins / JENKINS-59793 Possible thread leak 'QueueSubTaskMetrics' in metrics Issue Type: Bug Assignee: Unassigned Components: metrics-plugin Created: 2019-10-15 16:41 Environment: Metrics 4.0.2.5 Labels: plugin Priority: Major Reporter: Ramon Leon In one large instance we can see 3000 threads with this shape:   "QueueSubTaskMetrics [#11342]" #5508106 daemon prio=5 os_prio=0 tid=0x00007efcf085a800 nid=0x52c7 in Object.wait() [0x00007efbccb32000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) at java.lang.Object.wait(Object.java:502) at hudson.remoting.AsyncFutureImpl.get(AsyncFutureImpl.java:75) - locked <0x0000000512c01d10> (a hudson.model.queue.FutureImpl) at jenkins.metrics.impl.JenkinsMetricProviderImpl.lambda$asSupplier$3(JenkinsMetricProviderImpl.java:1142) at jenkins.metrics.impl.JenkinsMetricProviderImpl$$Lambda$388/1851215464.get(Unknown Source) at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Locked ownable synchronizers: - <0x00000004dc401fb0> (a java.util.concurrent.ThreadPoolExecutor$Worker)   There is way less number of jobs running or waiting (130) and the number of these threads never decreases. After investigating the code: Metrics listens to the queue with a QueueListener creating threads with the name QueueSubTaskMetrics The 3000 threads shown are all waiting for a future to be completed. This future is waiting for the task to start and complete: https://github.com/jenkinsci/metrics-plugin/commit/e803bc3b82b54bfe27e66a6393dedf53bdf1896e#diff-b02885f3ba6b4982b5322b73e664c0b6R907, which never happens. It’s hung on hudson.remoting.AsyncFutureImpl.get: while(!completed) wait(); I think it could be avoided calling the get method with a timeout instead of getting blocked there: https://github.com/jenkinsci/metrics-plugin/commit/e803bc3b82b54bfe27e66a6393dedf53bdf1896e#diff-b02885f3ba6b4982b5322b73e664c0b6R1049     Add Comment   This message was sent by Atlassian Jira (v7.13.6#713006-sha1:cc4451f) -- You received this message because you are subscribed to the Google Groups "Jenkins Issues" group. To unsubscribe from this group and stop receiving emails from it, send an email to jenkinsci-issues+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jenkinsci-issues/JIRA.202523.1571157685000.8269.1571157720181%40Atlassian.JIRA.