Hi ,
I turn off major compaction
<property>
<name>hbase.hregion.majorcompaction</name>
<value>*0*</value>
<description>The time (in miliseconds) between 'major' compactions of
all
HStoreFiles in a region. Default: 1 day.
</description>
</property>
and run from hbase shell
hbase(main):004:0> major_compact 'MYTABLE'
0 row(s) in 0.1760 seconds
--What does the responce mean : 0 row(s) in 0.1760 seconds? Does it means
that major compaction will be scheduled and will be done asynchronously?
--What is the way to see how the major compaction process is executing (log
files or something else )
Thanks.
Oleg.
On Mon, May 16, 2011 at 9:10 PM, Stack <[email protected]> wrote:
> On Mon, May 16, 2011 at 3:42 AM, Oleg Ruchovets <[email protected]>
> wrote:
> > I want to ask about major compaction best practices:
> >
> > 1) Have we to run it automatically or manually
>
> Major compaction runs once a day by default. It has a tendency
> whereby it will start just when you do not want it to run. So, change
> the configuration or run the compaction manually yourself at request
> downtimes (Running it manually is a pretty common practise).
>
> > 2) How ofter it should run
>
> Depends (Sorry).
>
> Major compactions clean up data that has been deleted or
> aged/versioned out of consideration. This clean up can help improve
> performance if there are obsoleted versions/deletes that the Scans and
> Gets do not have to continuously skip.
>
> Study your system. See what effect a major compaction has, if any, on
> your setup.
>
> > 3) Where can I read about compaction process and does it have potential
> > problem that I should know.
> >
>
>
> What Doug said,
> St.Ack
>
