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Posted to issues@hbase.apache.org by "liang xie (JIRA)" <ji...@apache.org> on 2012/12/03 09:37:59 UTC
[jira] [Commented] (HBASE-1648) heap usage and limit reporting
doesn't work as expected when using G1 GC
[ https://issues.apache.org/jira/browse/HBASE-1648?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13508579#comment-13508579 ]
liang xie commented on HBASE-1648:
----------------------------------
[~saint.ack@gmail.com] yes, it should be safe. we should not use G1 before JDK7u4
And also, i tried in a hbase0.94.0 + jdk6u22 + G1GC test env(not a good choice, aha):
hbase(main):003:0> status 'simple'
2 live servers
ha3:60020 1354522267193
requestsPerSecond=0, numberOfOnlineRegions=1, usedHeapMB=38, maxHeapMB=200
ha2:60020 1354551060862
requestsPerSecond=0, numberOfOnlineRegions=6, usedHeapMB=88, maxHeapMB=200
0 dead servers
Aggregate load: 0, regions: 7
the output is fine
And, i tried with jdk7u9 + G1GC as well:
hbase(main):002:0> status 'simple'
2 live servers
ha2:60020 1354552532489
requestsPerSecond=0, numberOfOnlineRegions=5, usedHeapMB=46, maxHeapMB=200
ha3:60020 1354523738930
requestsPerSecond=0, numberOfOnlineRegions=2, usedHeapMB=44, maxHeapMB=200
0 dead servers
Aggregate load: 0, regions: 7
still good
> heap usage and limit reporting doesn't work as expected when using G1 GC
> ------------------------------------------------------------------------
>
> Key: HBASE-1648
> URL: https://issues.apache.org/jira/browse/HBASE-1648
> Project: HBase
> Issue Type: Bug
> Environment: Linux Centos x86_64 5.3, Sun JDK 1.6.0_14 (HotSpot 64-Bit Server VM build 14.0-b16)
> Reporter: Andrew Purtell
> Priority: Minor
>
> Getting some early experience with the G1 GC.
> Running with -Xmx1000m and HBASE_OPTS set to "-XX:+UnlockExperimentalVMOpts -XX:+UseG1GC". Regionserver heap use reports are not of much use:
> {noformat}
> hbase(main):001:0> status 'simple'
> 3 live servers
> test3:60020 1247389283042
> requests=0, regions=1, usedHeap=0, maxHeap=41
> test2:60020 1247389219994
> requests=0, regions=1, usedHeap=0, maxHeap=41
> test4:60020 1247389324563
> requests=0, regions=2, usedHeap=0, maxHeap=41
> 0 dead servers
> {noformat}
> top is about right:
> {noformat}
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> 23988 hadoop 24 0 1492m 98m 10m S 0.0 2.5 0:02.65 java
> {noformat}
> Incidentally, don't try -XX:+UseG1GC and -XX:+DoEscapeAnalysis together or the JVM will rapidly segfault.
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