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HBase >> mail # user >> Storing images in Hbase


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Re: Storing images in Hbase
AFAIK, namenode would not like tracking 20 billion small files :)

-jack

On Sat, Jan 26, 2013 at 6:00 PM, S Ahmed <[EMAIL PROTECTED]> wrote:
> That's pretty amazing.
>
> What I am confused is, why did you go with hbase and not just straight into
> hdfs?
>
>
>
>
> On Fri, Jan 25, 2013 at 2:41 AM, Jack Levin <[EMAIL PROTECTED]> wrote:
>
>> Two people including myself, its fairly hands off. Took about 3 months to
>> tune it right, however we did have had multiple years of experience with
>> datanodes and hadoop in general, so that was a good boost.
>>
>> We have 4 hbase clusters today, image store being largest
>> On Jan 24, 2013 2:14 PM, "S Ahmed" <[EMAIL PROTECTED]> wrote:
>>
>> > Jack, out of curiosity, how many people manage the hbase related servers?
>> >
>> > Does it require constant monitoring or its fairly hands-off now?  (or a
>> bit
>> > of both, early days was getting things write/learning and now its purring
>> > along).
>> >
>> >
>> > On Wed, Jan 23, 2013 at 11:53 PM, Jack Levin <[EMAIL PROTECTED]> wrote:
>> >
>> > > Its best to keep some RAM for caching of the filesystem, besides we
>> > > also run datanode which takes heap as well.
>> > > Now, please keep in mind that even if you specify heap of say 5GB, if
>> > > your server opens threads to communicate with other systems via RPC
>> > > (which hbase does a lot), you will indeed use HEAP +
>> > > Nthreads*thread*kb_size.  There is a good Sun Microsystems document
>> > > about it. (I don't have the link handy).
>> > >
>> > > -Jack
>> > >
>> > >
>> > >
>> > > On Mon, Jan 21, 2013 at 5:10 PM, Varun Sharma <[EMAIL PROTECTED]>
>> > wrote:
>> > > > Thanks for the useful information. I wonder why you use only 5G heap
>> > when
>> > > > you have an 8G machine ? Is there a reason to not use all of it (the
>> > > > DataNode typically takes a 1G of RAM)
>> > > >
>> > > > On Sun, Jan 20, 2013 at 11:49 AM, Jack Levin <[EMAIL PROTECTED]>
>> > wrote:
>> > > >
>> > > >> I forgot to mention that I also have this setup:
>> > > >>
>> > > >> <property>
>> > > >>   <name>hbase.hregion.memstore.flush.size</name>
>> > > >>   <value>33554432</value>
>> > > >>   <description>Flush more often. Default: 67108864</description>
>> > > >> </property>
>> > > >>
>> > > >> This parameter works on per region amount, so this means if any of
>> my
>> > > >> 400 (currently) regions on a regionserver has 30MB+ in memstore, the
>> > > >> hbase will flush it to disk.
>> > > >>
>> > > >>
>> > > >> Here are some metrics from a regionserver:
>> > > >>
>> > > >> requests=2, regions=370, stores=370, storefiles=1390,
>> > > >> storefileIndexSize=304, memstoreSize=2233, compactionQueueSize=0,
>> > > >> flushQueueSize=0, usedHeap=3516, maxHeap=4987,
>> > > >> blockCacheSize=790656256, blockCacheFree=255245888,
>> > > >> blockCacheCount=2436, blockCacheHitCount=218015828,
>> > > >> blockCacheMissCount=13514652, blockCacheEvictedCount=2561516,
>> > > >> blockCacheHitRatio=94, blockCacheHitCachingRatio=98
>> > > >>
>> > > >> Note, that memstore is only 2G, this particular regionserver HEAP is
>> > set
>> > > >> to 5G.
>> > > >>
>> > > >> And last but not least, its very important to have good GC setup:
>> > > >>
>> > > >> export HBASE_OPTS="$HBASE_OPTS -verbose:gc -Xms5000m
>> > > >> -XX:CMSInitiatingOccupancyFraction=70 -XX:+PrintGCDetails
>> > > >> -XX:+PrintGCDateStamps
>> > > >> -XX:+HeapDumpOnOutOfMemoryError
>> -Xloggc:$HBASE_HOME/logs/gc-hbase.log
>> > \
>> > > >> -XX:MaxTenuringThreshold=15 -XX:SurvivorRatio=8 \
>> > > >> -XX:+UseParNewGC \
>> > > >> -XX:NewSize=128m -XX:MaxNewSize=128m \
>> > > >> -XX:-UseAdaptiveSizePolicy \
>> > > >> -XX:+CMSParallelRemarkEnabled \
>> > > >> -XX:-TraceClassUnloading
>> > > >> "
>> > > >>
>> > > >> -Jack
>> > > >>
>> > > >> On Thu, Jan 17, 2013 at 3:29 PM, Varun Sharma <[EMAIL PROTECTED]>
>> > > wrote:
>> > > >> > Hey Jack,
>> > > >> >
>> > > >> > Thanks for the useful information. By flush size being 15 %, do
>> you
>> > > mean
>> > > >> > the memstore flush size ? 15 % would mean close to 1G, have you