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Hadoop QA commented on HBASE-15742: ----------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:red}-1{color} | {color:red} patch {color} | {color:red} 0m 4s {color} | {color:red} HBASE-15742 does not apply to master. Rebase required? Wrong Branch? See https://yetus.apache.org/documentation/0.2.1/precommit-patchnames for help. {color} | \\ \\ || Subsystem || Report/Notes || | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12801925/HBASE-15742-0.98-v1.patch | | JIRA Issue | HBASE-15742 | | Console output | https://builds.apache.org/job/PreCommit-HBASE-Build/1730/console | | Powered by | Apache Yetus 0.2.1 http://yetus.apache.org | This message was automatically generated. > Reduce allocation of objects in metrics > --------------------------------------- > > Key: HBASE-15742 > URL: https://issues.apache.org/jira/browse/HBASE-15742 > Project: HBase > Issue Type: Bug > Affects Versions: 1.3.0, 1.2.1, 1.0.3, 1.1.4, 0.98.19 > Reporter: Phil Yang > Assignee: Phil Yang > Fix For: 2.0.0, 1.3.0, 1.4.0, 1.2.2, 0.98.20 > > Attachments: HBASE-15742-0.98-v1.patch, > HBASE-15742-branch-1-v1.patch, HBASE-15742-branch-1.1-v1.patch, > HBASE-15742-branch-1.2-v1.patch, HBASE-15742-branch-1.2-v2.patch, > HBASE-15742-v1.patch, HBASE-15742-v2.patch, HBASE-15742-v3.patch, > HBASE-15742-v4.patch > > > We use JMX and o.a.h.metrics2 to do some metrics on regions, tables, region > servers and cluster. We use MetricsInfo to show the information of metrics, > and we use Interns to cache MetricsInfo objects because it won't be changed. > However, in Interns there are some static values to limit the max cached > objects. We can only cache 2010 metrics, but we have dozens of metrics for > one region and we have some RS-level metrics in each RS and all metrics for > all regions will be saved in master. So each server will have thousands of > metrics, and we can not cache most of them. When we collect metrics by JMX, > we will create many objects which can be avoid. It increases the pressure of > GC and JMX has some caching logic so the objects can not be removed > immediately which increases the pressure more. > Interns is in Hadoop project, and I think the implementation is not suitable > for HBase. Because we can not know how many MetricsInfo we have, it depends > on the number of regions. And we can not set it unlimited because we should > remove the objects whose region is split, moved, or dropped. I think we can > use Guava's cache with expireAfterAccess which is very simple and convenient. > So we can add a new Interns class in HBase project first, and put it to > upstream later. > Moreover, in MutableHistogram#snapshot we create same Strings each time, we > can create them only in the first time. -- This message was sent by Atlassian JIRA (v6.3.4#6332)