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From Jean-Marc Spaggiari <jean-m...@spaggiari.org>
Subject Re: Disabled automated compaction - table still compacting
Date Tue, 09 Jul 2013 14:41:34 GMT
Hi David,

Minor compactions can be promoted to Major compactions when all the
files are selected for compaction. And the property below will not
avoid that to occur.

Section there: http://hbase.apache.org/book/regions.arch.html


2013/7/9 David Koch <ogdude@googlemail.com>:
> Hello,
> We disabled automated major compactions by setting
> hbase.hregion.majorcompaction=0.
> This was to avoid issues during buik import of data since compactions
> seemed to cause the running imports to crash. However, even after
> disabling, region server logs still show compactions going on, as well as
> aborted compactions. We also get compaction queue size warnings in Cloudera
> Manager.
> Why is this the case?
> To be fair, we only disabled automated compactions AFTER the import failed
> for the first time (yes, HBase was restarted) so maybe there are some
> trailing compactions, but the queue size keeps increasing which I guess
> should not be the case. Then again, I don't know how aborted compactions
> are counted - i.e not sure whether or not to trust the metrics on this.
> A bit more about what I am trying to accomplish:
> I am bulk loading about 100 indexed .lzo files with 20 * 10^6 Key-Value
> (0.5kb) each into an HBase table. Each file is loaded by a separate Mapper
> job, several of these jobs run in parallel to make sure all task trackers
> are used. Key distribution is the same in each file so even region growth
> is to be expected. We did not pre-split the table as it does not seem to
> have been a limiting factor earlier.
> On a related note. What if any experience do other HBase/Cloudera users
> have with the Snapshotting feature detailed below?
> http://www.cloudera.com/content/cloudera-content/cloudera-
> docs/CDH4/4.2.0/CDH4-Installation-Guide/cdh4ig_topic_20_12.html
> We need of a robust way to do inter-cluster cloning/back-up of tables,
> preferably without taking the source table offline or impacting performance
> of the source cluster. We only use HDFS files for importing because the
> CopyTable job needs to run on the source cluster and cannot be resumed once
> it fails.
> Thanks,
> /David

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