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https://issues.apache.org/jira/browse/HBASE-16287?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15397674#comment-15397674
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Hadoop QA commented on HBASE-16287:
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| (x) *{color:red}-1 overall{color}* |
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|| Vote || Subsystem || Runtime || Comment ||
| {color:red}-1{color} | {color:red} patch {color} | {color:red} 0m 3s {color}
| {color:red} HBASE-16287 does not apply to master. Rebase required? Wrong
Branch? See https://yetus.apache.org/documentation/0.2.1/precommit-patchnames
for help. {color} |
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|| Subsystem || Report/Notes ||
| JIRA Patch URL |
https://issues.apache.org/jira/secure/attachment/12820710/HBASE-16287-v2.patch |
| JIRA Issue | HBASE-16287 |
| Console output |
https://builds.apache.org/job/PreCommit-HBASE-Build/2809/console |
| Powered by | Apache Yetus 0.2.1 http://yetus.apache.org |
This message was automatically generated.
> LruBlockCache size should not exceed acceptableSize too many
> ------------------------------------------------------------
>
> Key: HBASE-16287
> URL: https://issues.apache.org/jira/browse/HBASE-16287
> Project: HBase
> Issue Type: Improvement
> Components: BlockCache
> Reporter: Yu Sun
> Assignee: Yu Sun
> Attachments: HBASE-16287-v1.patch, HBASE-16287-v2.patch
>
>
> Our regionserver has a configuation as bellow：
> -Xmn4g -Xms32g -Xmx32g -XX:SurvriorRatio=2 -XX:+UseConcMarkSweepGC
> also we only use blockcache,and set hfile.block.cache.size = 0.3 in
> hbase_site.xml,so under this configuration, the lru block cache size will
> be(32g-1g)*0.3=9.3g. but in some scenarios，some of the rs will occur
> continuous FullGC for hours and most importantly, after FullGC most of the
> object in old will not be GCed. so we dump the heap and analyse with MAT and
> we observed a obvious memory leak in LruBlockCache, which occpy about 16g
> memory, then we set set class LruBlockCache log level to TRACE and observed
> this in log:
> {quote}
> 2016-07-22 12:17:58,158 INFO [LruBlockCacheStatsExecutor]
> hfile.LruBlockCache: totalSize=15.29 GB, freeSize=-5.99 GB, max=9.30 GB,
> blockCount=628182, accesses=101799469125, hits=93517800259, hitRatio=91.86%,
> , cachingAccesses=99462650031, cachingHits=93468334621,
> cachingHitsRatio=93.97%, evictions=238199, evicted=4776350518,
> evictedPerRun=20051.93359375{quote}
> we can see blockcache size has exceeded acceptableSize too many, which will
> cause the FullGC more seriously.
> Afterfter some investigations, I found in this function:
> {code:borderStyle=solid}
> public void cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean
> inMemory,
> final boolean cacheDataInL1) {
> {code}
> No matter the blockcache size has been used, just put the block into it. but
> if the evict thread is not fast enough, blockcache size will increament
> significantly.
> So here I think we should have a check, for example, if the blockcache size >
> 1.2 * acceptableSize(), just return and dont put into it until the blockcache
> size if under watrmark. if this is reasonable, I can make a small patch for
> this.
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