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Re: Read thruput
I was aware of that discussion which was about MAX_FILESIZE and BLOCKSIZE

My suggestion was about block cache percentage.

Cheers
On Mon, Apr 1, 2013 at 4:57 AM, Vibhav Mundra <[EMAIL PROTECTED]> wrote:

> I have used the following site:
> http://grokbase.com/t/hbase/user/11bat80x7m/row-get-very-slow
>
> to lessen the value of block cache.
>
> -Vibhav
>
>
> On Mon, Apr 1, 2013 at 4:23 PM, Ted <[EMAIL PROTECTED]> wrote:
>
> > Can you increase block cache size ?
> >
> > What version of hbase are you using ?
> >
> > Thanks
> >
> > On Apr 1, 2013, at 3:47 AM, Vibhav Mundra <[EMAIL PROTECTED]> wrote:
> >
> > > The typical size of each of my row is less than 1KB.
> > >
> > > Regarding the memory, I have used 8GB for Hbase regionservers and 4 GB
> > for
> > > datanodes and I dont see them completely used. So I ruled out the GC
> > aspect.
> > >
> > > In case u still believe that GC is an issue, I will upload the gc logs.
> > >
> > > -Vibhav
> > >
> > >
> > > On Mon, Apr 1, 2013 at 3:46 PM, ramkrishna vasudevan <
> > > [EMAIL PROTECTED]> wrote:
> > >
> > >> Hi
> > >>
> > >> How big is your row?  Are they wider rows and what would be the size
> of
> > >> every cell?
> > >> How many read threads are getting used?
> > >>
> > >>
> > >> Were you able to take a thread dump when this was happening?  Have you
> > seen
> > >> the GC log?
> > >> May be need some more info before we can think of the problem.
> > >>
> > >> Regards
> > >> Ram
> > >>
> > >>
> > >> On Mon, Apr 1, 2013 at 3:39 PM, Vibhav Mundra <[EMAIL PROTECTED]>
> wrote:
> > >>
> > >>> Hi All,
> > >>>
> > >>> I am trying to use Hbase for real-time data retrieval with a timeout
> of
> > >> 50
> > >>> ms.
> > >>>
> > >>> I am using 2 machines as datanode and regionservers,
> > >>> and one machine as a master for hadoop and Hbase.
> > >>>
> > >>> But I am able to fire only 3000 queries per sec and 10% of them are
> > >> timing
> > >>> out.
> > >>> The database has 60 million rows.
> > >>>
> > >>> Are these figure okie, or I am missing something.
> > >>> I have used the scanner caching to be equal to one, because for each
> > time
> > >>> we are fetching a single row only.
> > >>>
> > >>> Here are the various configurations:
> > >>>
> > >>> *Our schema
> > >>> *{NAME => 'mytable', FAMILIES => [{NAME => 'cf', DATA_BLOCK_ENCODING
> =>
> > >>> 'NONE', BLOOMFILTER => 'ROWCOL', REPLICATION_SCOPE => '0',
> COMPRESSION
> > =>
> > >>> 'GZ', VERSIONS => '1', TTL => '2147483647', MIN_VERSIONS => '0', KEE
> > >>> P_DELETED_CELLS => 'false', BLOCKSIZE => '8192', ENCODE_ON_DISK =>
> > >> 'true',
> > >>> IN_MEMORY => 'false', BLOCKCACHE => 'true'}]}
> > >>>
> > >>> *Configuration*
> > >>> 1 Machine having both hbase and hadoop master
> > >>> 2 machines having both region server node and datanode
> > >>> total 285 region servers
> > >>>
> > >>> *Machine Level Optimizations:*
> > >>> a)No of file descriptors is 1000000(ulimit -n gives 1000000)
> > >>> b)Increase the read-ahead value to 4096
> > >>> c)Added noatime,nodiratime to the disks
> > >>>
> > >>> *Hadoop Optimizations:*
> > >>> dfs.datanode.max.xcievers = 4096
> > >>> dfs.block.size = 33554432
> > >>> dfs.datanode.handler.count = 256
> > >>> io.file.buffer.size = 65536
> > >>> hadoop data is split on 4 directories, so that different disks are
> > being
> > >>> accessed
> > >>>
> > >>> *Hbase Optimizations*:
> > >>>
> > >>> hbase.client.scanner.caching=1  #We have specifcally added this, as
> we
> > >>> return always one row.
> > >>> hbase.regionserver.handler.count=3200
> > >>> hfile.block.cache.size=0.35
> > >>> hbase.hregion.memstore.mslab.enabled=true
> > >>> hfile.min.blocksize.size=16384
> > >>> hfile.min.blocksize.size=4
> > >>> hbase.hstore.blockingStoreFiles=200
> > >>> hbase.regionserver.optionallogflushinterval=60000
> > >>> hbase.hregion.majorcompaction=0
> > >>> hbase.hstore.compaction.max=100
> > >>> hbase.hstore.compactionThreshold=100
> > >>>
> > >>> *Hbase-GC
> > >>> *-XX:+UseConcMarkSweepGC -XX:+UseParNewGC
> -XX:+CMSParallelRemarkEnabled