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HBase >> mail # user >> HBase scan performance decreases over time.


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Re: HBase scan performance decreases over time.
Have you looked at http://hbase.apache.org/book.html#performance ?

Thanks

On Sat, Nov 3, 2012 at 12:50 PM, David Koch <[EMAIL PROTECTED]> wrote:

> Hello Ted,
>
> We never initiate major compaction manually. I have not looked at I/O
> balance between nodes in detail. We have noticed that after running for a
> couple of weeks HBase seems to spend hours pushing blocks between nodes in
> order to optimize things. We add data daily in one ~30gb push to several
> tables. Sometimes nodes get added to the running system.
>
> Where can I get more information on how to carry out performance related
> HBase administrative tasks?
>
> Thank you,
>
> /David
>
>
> On Sat, Nov 3, 2012 at 4:42 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
>
> > Can you tell us how often you run major compaction after the import ?
> > Have you noticed imbalanced read / write requests in the cluster ?
> Meaning
> > subset of region servers receive bulk of the writes.
> >
> > We do some manual movement of regions when the above happens.
> >
> > Cheers
> >
> > On Sat, Nov 3, 2012 at 8:12 AM, David Koch <[EMAIL PROTECTED]>
> wrote:
> >
> > > Hello,
> > >
> > > Every now and then we need to flatten our cluster and re-import all
> data
> > > from log files (changes in data format, etc.) Afterwards we notice a
> > > significant increase in scan performance. As data is added and shuffled
> > > around between region servers, performance goes down again over time
> > (say a
> > > couple of weeks). Are there any routine operations that one should run
> > > manually, or settings to activate in the HBase configuration to keep
> the
> > > data well distributed? We use HBase 0.92 as part of a Cloudera4
> cluster.
> > >
> > > Thank you,
> > >
> > > /David
> > >
> >
>