I've never tried it, HBASE worked out nicely for this task, caching and all is a bonus for files.
-jack On Mon, Jan 28, 2013 at 2:01 AM, Adrien Mogenet <[email protected]> wrote: > Could HCatalog be an option ? > Le 26 janv. 2013 21:56, "Jack Levin" <[email protected]> a écrit : >> >> 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 >> >> seen >> >> > > any >> >> > > >> > issues with flushes taking too long ? >> >> > > >> > >> >> > > >> > Thanks >> >> > > >> > Varun >> >> > > >> > >> >> > > >> > On Sun, Jan 13, 2013 at 8:17 AM, Jack Levin <[email protected] >> >> >> > > wrote: >> >> > > >> > >> >> > > >> >> That's right, Memstore size , not flush size is increased. >> >> > Filesize >> >> > > is >> >> > > >> >> 10G. Overall write cache is 60% of heap and read cache is > 20%. >> >> > Flush >> >> > > >> size >> >> > > >> >> is 15%. 64 maxlogs at 128MB. One namenode server, one > secondary >> >> > that >> >> > > >> can >> >> > > >> >> be promoted. On the way to hbase images are written to a > queue, >> >> so >> >> > > >> that we >> >> > > >> >> can take Hbase down for maintenance and still do inserts > later. >> >> > > >> ImageShack >> >> > > >> >> has ‘perma cache’ servers that allows writes and serving of > data >> >> > even >> >> > > >> when >> >> > > >> >> hbase is down for hours, consider it 4th replica 😉 outside > of >> >> > hadoop >> >> > > >> >> >> >> > > >> >> Jack >> >> > > >> >> >> >> > > >> >> *From:* Mohit Anchlia <[email protected]> >> >> > > >> >> *Sent:* January 13, 2013 7:48 AM >> >> > > >> >> *To:* [email protected] >> >> > > >> >> *Subject:* Re: Storing images in Hbase >> >> > > >> >> >> >> > > >> >> Thanks Jack for sharing this information. This definitely > makes >> >> > sense >> >> > > >> when >> >> > > >> >> using the type of caching layer. You mentioned about > increasing >> >> > write >> >> > > >> >> cache, I am assuming you had to increase the following > parameters >> >> > in >> >> > > >> >> addition to increase the memstore size: >> >> > > >> >> >> >> > > >> >> hbase.hregion.max.filesize >> >> > > >> >> hbase.hregion.memstore.flush.size >> >> > > >> >> >> >> > > >> >> On Fri, Jan 11, 2013 at 9:47 AM, Jack Levin < > [email protected]> >> >> > > wrote: >> >> > > >> >> >> >> > > >> >> > We buffer all accesses to HBASE with Varnish SSD based > caching >> >> > > layer. >> >> > > >> >> > So the impact for reads is negligible. We have 70 node >> >> cluster, >> >> > 8 >> >> > > GB >> >> > > >> >> > of RAM per node, relatively weak nodes (intel core 2 duo), > with >> >> > > >> >> > 10-12TB per server of disks. Inserting 600,000 images per > day. >> >> > We >> >> > > >> >> > have relatively little of compaction activity as we made > our >> >> > write >> >> > > >> >> > cache much larger than read cache - so we don't experience >> >> region >> >> > > file >> >> > > >> >> > fragmentation as much. >> >> > > >> >> > >> >> > > >> >> > -Jack >> >> > > >> >> > >> >> > > >> >> > On Fri, Jan 11, 2013 at 9:40 AM, Mohit Anchlia < >> >> > > >> [email protected]> >> >> > > >> >> > wrote: >> >> > > >> >> > > I think it really depends on volume of the traffic, data >> >> > > >> distribution >> >> > > >> >> per >> >> > > >> >> > > region, how and when files compaction occurs, number of > nodes >> >> > in >> >> > > the >> >> > > >> >> > > cluster. In my experience when it comes to blob data > where >> >> you >> >> > > are >> >> > > >> >> > serving >> >> > > >> >> > > 10s of thousand+ requests/sec writes and reads then it's > very >> >> > > >> difficult >> >> > > >> >> > to >> >> > > >> >> > > manage HBase without very hard operations and > maintenance in >> >> > > play. >> >> > > >> Jack >> >> > > >> >> > > earlier mentioned they have 1 billion images, It would be >> >> > > >> interesting >> >> > > >> >> to >> >> > > >> >> > > know what they see in terms of compaction, no of > requests per >> >> > > sec. >> >> > > >> I'd >> >> > > >> >> be >> >> > > >> >> > > surprised that in high volume site it can be done > without any >> >> > > >> Caching >> >> > > >> >> > layer >> >> > > >> >> > > on the top to alleviate IO spikes that occurs because of > GC >> >> and >> >> > > >> >> > compactions. >> >> > > >> >> > > >> >> > > >> >> > > On Fri, Jan 11, 2013 at 7:27 AM, Mohammad Tariq < >> >> > > [email protected] >> >> > > >> > >> >> > > >> >> > wrote: >> >> > > >> >> > > >> >> > > >> >> > >> IMHO, if the image files are not too huge, Hbase can >> >> > efficiently >> >> > > >> serve >> >> > > >> >> > the >> >> > > >> >> > >> purpose. You can store some additional info along with > the >> >> > file >> >> > > >> >> > depending >> >> > > >> >> > >> upon your search criteria to make the search faster. > Say if >> >> > you >> >> > > >> want >> >> > > >> >> to >> >> > > >> >> > >> fetch images by the type, you can store images in one > column >> >> > and >> >> > > >> its >> >> > > >> >> > >> extension in another column(jpg, tiff etc). >> >> > > >> >> > >> >> >> > > >> >> > >> BTW, what exactly is the problem which you are facing. > You >> >> > have >> >> > > >> >> written >> >> > > >> >> > >> "But I still cant do it"? >> >> > > >> >> > >> >> >> > > >> >> > >> Warm Regards, >> >> > > >> >> > >> Tariq >> >> > > >> >> > >> https://mtariq.jux.com/ >> >> > > >> >> > >> >> >> > > >> >> > >> >> >> > > >> >> > >> On Fri, Jan 11, 2013 at 8:30 PM, Michael Segel < >> >> > > >> >> > [email protected] >> >> > > >> >> > >> >wrote: >> >> > > >> >> > >> >> >> > > >> >> > >> > That's a viable option. >> >> > > >> >> > >> > HDFS reads are faster than HBase, but it would require >> >> first >> >> > > >> hitting >> >> > > >> >> > the >> >> > > >> >> > >> > index in HBase which points to the file and then > fetching >> >> > the >> >> > > >> file. >> >> > > >> >> > >> > It could be faster... we found storing binary data in > a >> >> > > sequence >> >> > > >> >> file >> >> > > >> >> > and >> >> > > >> >> > >> > indexed on HBase to be faster than HBase, however, > YMMV >> >> and >> >> > > HBase >> >> > > >> >> has >> >> > > >> >> > >> been >> >> > > >> >> > >> > improved since we did that project.... >> >> > > >> >> > >> > >> >> > > >> >> > >> > >> >> > > >> >> > >> > On Jan 10, 2013, at 10:56 PM, shashwat shriparv < >> >> > > >> >> > >> [email protected]> >> >> > > >> >> > >> > wrote: >> >> > > >> >> > >> > >> >> > > >> >> > >> > > Hi Kavish, >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > i have a better idea for you copy your image files > to a >> >> > > single >> >> > > >> >> file >> >> > > >> >> > on >> >> > > >> >> > >> > > hdfs, and if new image comes append it to the > existing >> >> > > image, >> >> > > >> and >> >> > > >> >> > keep >> >> > > >> >> > >> > and >> >> > > >> >> > >> > > update the metadata and the offset to the HBase. > Because >> >> > if >> >> > > you >> >> > > >> >> put >> >> > > >> >> > >> > bigger >> >> > > >> >> > >> > > image in hbase it wil lead to some issue. >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > ∞ >> >> > > >> >> > >> > > Shashwat Shriparv >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > >> >> > > >> >> > >> > > On Fri, Jan 11, 2013 at 9:21 AM, lars hofhansl < >> >> > > >> [email protected]> >> >> > > >> >> > >> wrote: >> >> > > >> >> > >> > > >> >> > > >> >> > >> > >> Interesting. That's close to a PB if my math is >> >> correct. >> >> > > >> >> > >> > >> Is there a write up about this somewhere? Something >> >> that >> >> > we >> >> > > >> could >> >> > > >> >> > link >> >> > > >> >> > >> > >> from the HBase homepage? >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> -- Lars >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> ----- Original Message ----- >> >> > > >> >> > >> > >> From: Jack Levin <[email protected]> >> >> > > >> >> > >> > >> To: [email protected] >> >> > > >> >> > >> > >> Cc: Andrew Purtell <[email protected]> >> >> > > >> >> > >> > >> Sent: Thursday, January 10, 2013 9:24 AM >> >> > > >> >> > >> > >> Subject: Re: Storing images in Hbase >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> We stored about 1 billion images into hbase with > file >> >> > size >> >> > > up >> >> > > >> to >> >> > > >> >> > 10MB. >> >> > > >> >> > >> > >> Its been running for close to 2 years without > issues >> >> and >> >> > > >> serves >> >> > > >> >> > >> > >> delivery of images for Yfrog and ImageShack. If > you >> >> have >> >> > > any >> >> > > >> >> > >> > >> questions about the setup, I would be glad to > answer >> >> > them. >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> -Jack >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> On Sun, Jan 6, 2013 at 1:09 PM, Mohit Anchlia < >> >> > > >> >> > [email protected] >> >> > > >> >> > >> > >> >> > > >> >> > >> > >> wrote: >> >> > > >> >> > >> > >>> I have done extensive testing and have found that >> >> blobs >> >> > > don't >> >> > > >> >> > belong >> >> > > >> >> > >> in >> >> > > >> >> > >> > >> the >> >> > > >> >> > >> > >>> databases but are rather best left out on the file >> >> > system. >> >> > > >> >> Andrew >> >> > > >> >> > >> > >> outlined >> >> > > >> >> > >> > >>> issues that you'll face and not to mention IO > issues >> >> > when >> >> > > >> >> > compaction >> >> > > >> >> > >> > >> occurs >> >> > > >> >> > >> > >>> over large files. >> >> > > >> >> > >> > >>> >> >> > > >> >> > >> > >>> On Sun, Jan 6, 2013 at 12:52 PM, Andrew Purtell < >> >> > > >> >> > [email protected] >> >> > > >> >> > >> > >> >> > > >> >> > >> > >> wrote: >> >> > > >> >> > >> > >>> >> >> > > >> >> > >> > >>>> I meant this to say "a few really large values" >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> On Sun, Jan 6, 2013 at 12:49 PM, Andrew Purtell < >> >> > > >> >> > >> [email protected]> >> >> > > >> >> > >> > >>>> wrote: >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>>> Consider if the split threshold is 2 GB but > your one >> >> > row >> >> > > >> >> > contains >> >> > > >> >> > >> 10 >> >> > > >> >> > >> > >> GB >> >> > > >> >> > >> > >>>> as >> >> > > >> >> > >> > >>>>> really large value. >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> -- >> >> > > >> >> > >> > >>>> Best regards, >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> - Andy >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >>>> Problems worthy of attack prove their worth by >> >> hitting >> >> > > >> back. - >> >> > > >> >> > Piet >> >> > > >> >> > >> > Hein >> >> > > >> >> > >> > >>>> (via Tom White) >> >> > > >> >> > >> > >>>> >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> >> >> > > >> >> > >> > >> >> > > >> >> > >> > >> >> > > >> >> > >> >> >> > > >> >> > >> >> > > >> >> >> >> > > >> >> >> > > >> >> > >> >>
