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https://issues.apache.org/jira/browse/HADOOP-2731?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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stack updated HADOOP-2731:
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Status: Patch Available (was: Open)
Passes tests locally.
I think this issue a blocker but won't mark it so until Bryan Duxbury test says
this patch is an improvement over old behavior (and jimk said he'd review).
Meantime, moving it to hudson to make sure its ok w/ him in case we end up
committing.
> [hbase] Under load, regions become extremely large and eventually cause
> region servers to become unresponsive
> -------------------------------------------------------------------------------------------------------------
>
> Key: HADOOP-2731
> URL: https://issues.apache.org/jira/browse/HADOOP-2731
> Project: Hadoop Core
> Issue Type: Bug
> Components: contrib/hbase
> Reporter: Bryan Duxbury
> Attachments: split-v8.patch, split-v9.patch, split.patch
>
>
> When attempting to write to HBase as fast as possible, HBase accepts puts at
> a reasonably high rate for a while, and then the rate begins to drop off,
> ultimately culminating in exceptions reaching client code. In my testing, I
> was able to write about 370 10KB records a second to HBase until I reach
> around 1 million rows written. At that point, a moderate to large number of
> exceptions - NotServingRegionException, WrongRegionException, region offline,
> etc - begin reaching the client code. This appears to be because the
> retry-and-wait logic in HTable runs out of retries and fails.
> Looking at mapfiles for the regions from the command line shows that some of
> the mapfiles are between 1 and 2 GB in size, much more than the stated file
> size limit. Talking with Stack, one possible explanation for this is that the
> RegionServer is not choosing to compact files often enough, leading to many
> small mapfiles, which in turn leads to a few overlarge mapfiles. Then, when
> the time comes to do a split or "major" compaction, it takes an unexpectedly
> long time to complete these operations. This translates into errors for the
> client application.
> If I back off the import process and give the cluster some quiet time, some
> splits and compactions clearly do take place, because the number of regions
> go up and the number of mapfiles/region goes down. I can then begin writing
> again in earnest for a short period of time until the problem begins again.
> Both Marc Harris and myself have seen this behavior.
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