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Hadoop QA commented on HBASE-21991: ----------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m 0s{color} | {color:blue} Docker mode activated. {color} | | {color:red}-1{color} | {color:red} patch {color} | {color:red} 0m 7s{color} | {color:red} HBASE-21991 does not apply to branch-1. Rebase required? Wrong Branch? See https://yetus.apache.org/documentation/0.8.0/precommit-patchnames for help. {color} | \\ \\ || Subsystem || Report/Notes || | JIRA Issue | HBASE-21991 | | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12963047/hbase-21991.branch-1.001.patch | | Console output | https://builds.apache.org/job/PreCommit-HBASE-Build/16436/console | | Powered by | Apache Yetus 0.8.0 http://yetus.apache.org | This message was automatically generated. > Fix MetaMetrics issues - [Race condition, Faulty remove logic], few > improvements > -------------------------------------------------------------------------------- > > Key: HBASE-21991 > URL: https://issues.apache.org/jira/browse/HBASE-21991 > Project: HBase > Issue Type: Bug > Components: Coprocessors, metrics > Reporter: Sakthi > Assignee: Sakthi > Priority: Major > Attachments: hbase-21991.branch-1.001.patch, > hbase-21991.master.001.patch, hbase-21991.master.002.patch, > hbase-21991.master.003.patch, hbase-21991.master.004.patch, > hbase-21991.master.005.patch, hbase-21991.master.006.patch > > > Here is a list of the issues related to the MetaMetrics implementation: > +*Bugs*+: > # [_Lossy counting for top-k_] *Faulty remove logic of non-eligible meters*: > Under certain conditions, we might end up storing/exposing all the meters > rather than top-k-ish > # MetaMetrics can throw NPE resulting in aborting of the RS because of a > *Race Condition*. > +*Improvements*+: > # With high number of regions in the cluster, exposure of metrics for each > region blows up the JMX from ~140 Kbs to 100+ Mbs depending on the number of > regions. It's better to use *lossy counting to maintain top-k for region > metrics* as well. > # As the lossy meters do not represent actual counts, I think, it'll be > better to *rename the meters to include "lossy" in the name*. It would be > more informative while monitoring the metrics and there would be less > confusion regarding actual counts to lossy counts. -- This message was sent by Atlassian JIRA (v7.6.3#76005)