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Xiaoqiao He commented on HDFS-14997: ------------------------------------ Thanks [~weichiu], {quote}Question: I can imagine DNA_INVALIDATE taking a long time to process. Do we already have metrics or log messages when the block invalidation command taking too long? {quote} It looks no metrics or log to trace performance of IO operation (include some very long lock waiting times) in trunk according to my observation. I add them in my internal version. I also suggest to add them and next JIRA will work it if necessary. Thanks. > BPServiceActor process command from NameNode asynchronously > ----------------------------------------------------------- > > Key: HDFS-14997 > URL: https://issues.apache.org/jira/browse/HDFS-14997 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode > Reporter: Xiaoqiao He > Assignee: Xiaoqiao He > Priority: Major > Attachments: HDFS-14997.001.patch, HDFS-14997.002.patch, > HDFS-14997.003.patch, HDFS-14997.004.patch, HDFS-14997.005.patch > > > There are two core functions, report(#sendHeartbeat, #blockReport, > #cacheReport) and #processCommand in #BPServiceActor main process flow. If > processCommand cost long time it will block send report flow. Meanwhile > processCommand could cost long time(over 1000s the worst case I meet) when IO > load of DataNode is very high. Since some IO operations are under > #datasetLock, So it has to wait to acquire #datasetLock long time when > process some of commands(such as #DNA_INVALIDATE). In such case, #heartbeat > will not send to NameNode in-time, and trigger other disasters. > I propose to improve #processCommand asynchronously and not block > #BPServiceActor to send heartbeat back to NameNode when meet high IO load. > Notes: > 1. Lifeline could be one effective solution, however some old branches are > not support this feature. > 2. IO operations under #datasetLock is another issue, I think we should solve > it at another JIRA. -- 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