[ https://issues.apache.org/jira/browse/HDFS-16042?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17356468#comment-17356468 ]
Jim Brennan commented on HDFS-16042: ------------------------------------ [~ahussein] I believe this was filed due to an incident where decommissions were happening during a rolling upgrade. They were taking longer and with the fixed rate, they were holding the namesystem lock frequently enough that it was impacting other operations during the upgrade. [~kihwal], [~daryn] is this correct? Seems like a reasonable change to me. I will commit if you guys are ok with it. > DatanodeAdminMonitor scan should be delay based > ----------------------------------------------- > > Key: HDFS-16042 > URL: https://issues.apache.org/jira/browse/HDFS-16042 > Project: Hadoop HDFS > Issue Type: Bug > Components: datanode > Reporter: Ahmed Hussein > Assignee: Ahmed Hussein > Priority: Major > Labels: pull-request-available > Time Spent: 20m > Remaining Estimate: 0h > > In {{DatanodeAdminManager.activate()}}, the Monitor task is scheduled with a > fixed rate, ie. the period is from start1 -> start2. > {code:java} > executor.scheduleAtFixedRate(monitor, intervalSecs, intervalSecs, > TimeUnit.SECONDS); > {code} > According to Java API docs for {{scheduleAtFixedRate}}, > {quote}If any execution of this task takes longer than its period, then > subsequent executions may start late, but will not concurrently > execute.{quote} > It should be a fixed delay so it's end1 -> start1. > -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org