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https://issues.apache.org/jira/browse/HBASE-22072?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16806496#comment-16806496
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ramkrishna.s.vasudevan commented on HBASE-22072:
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bq.updateReaders and further updateReaders procedure does not consider
StoreScanner is closing or not.
Thanks [~pKirillov] for the analysis.
So you are saying that already the StoreScanner itself is getting closed and
during that time updateReaders is doing a new set of scanners as part of which
refCount increment happens.
Need to see if this is really possible - can you write a UT to see if this case
can be reproduced?
> High read/write intensive regions may cause long crash recovery
> ---------------------------------------------------------------
>
> Key: HBASE-22072
> URL: https://issues.apache.org/jira/browse/HBASE-22072
> Project: HBase
> Issue Type: Bug
> Components: Performance, Recovery
> Affects Versions: 2.1.2
> Reporter: Pavel
> Priority: Major
>
> Compaction of high read loaded region may leave compacted files undeleted
> because of existing scan references:
> INFO org.apache.hadoop.hbase.regionserver.HStore - Can't archive compacted
> file hdfs://hdfs-ha/hbase... because of either isCompactedAway=true or file
> has reference, isReferencedInReads=true, refCount=1, skipping for now
> If region is either high write loaded this happens quite often and region may
> have few storefiles and tons of undeleted compacted hdfs files.
> Region keeps all that files (in my case thousands) untill graceful region
> closing procedure, which ignores existing references and drop obsolete files.
> It works fine unless consuming some extra hdfs space, but only in case of
> normal region closing. If region server crashes than new region server,
> responsible for that overfiling region, reads hdfs folder and try to deal
> with all undeleted files, producing tons of storefiles, compaction tasks and
> consuming abnormal amount of memory, wich may lead to OutOfMemory Exception
> and further region servers crash. This stops writing to region because number
> of storefiles reach *hbase.hstore.blockingStoreFiles* limit, forces high GC
> duty and may take hours to compact all files into working set of files.
> Workaround is a periodically check hdfs folders files count and force region
> assign for ones with too many files.
> It could be nice if regionserver had a setting similar to
> hbase.hstore.blockingStoreFiles and invoke attempt to drop undeleted
> compacted files if number of files reaches this setting.
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