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Brahma Reddy Battula updated HDFS-12332: ---------------------------------------- Target Version/s: 3.4.0 (was: 3.3.0) Bulk update: moved all 3.3.0 non-blocker issues, please move back if it is a blocker. > Logging improvement suggestion for SampleStat function MinMax.add > ----------------------------------------------------------------- > > Key: HDFS-12332 > URL: https://issues.apache.org/jira/browse/HDFS-12332 > Project: Hadoop HDFS > Issue Type: Improvement > Components: metrics > Affects Versions: 3.0.0-alpha4 > Reporter: Xu Zhao > Priority: Minor > Attachments: hdfs-12332.patch > > > In order to debug performance anomlies, it is better to see when the max and > min value get updated in metrics. > For example, in our workload we would like to see the longest latency of a > write block request on DataNode. > The following metric updating code could possibly update the min/max value in > SampleStat class: > {code:java} > datanode.getMetrics().addWriteBlockOp(elapsed()); > datanode.getMetrics().incrWritesFromClient(peer.isLocal(), size); > {code} > Here I am attaching an attempt to patch it. > The patch just adds additional DEBUG level logging in the MinMax class and > prints the new value when it gets updated. > Please let me know what you think. For example, if this patch would introduce > too much noises, what is the best way to trace the read/writeBlock that has > the minimum/maximum latency? > Any comments are appreciated! -- 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