I imagine that you have developed some tools to help you dig through a log file. Is there tips and techniques that you can recommend to make it easier to scan through? Dave
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jean-Daniel Cryans Sent: Wednesday, May 26, 2010 4:01 PM To: [email protected] Subject: Re: Effect of turning major compactions off.. You can also post a full region server log file, we don't mind digging. Put it on a web server. J-D On Wed, May 26, 2010 at 12:03 PM, Vidhyashankar Venkataraman <[email protected]> wrote: > These are my current configs: > hbase.regionserver.handler.count 100 (Default was a much smaller number > like 25 or something) > hbase.hregion.memstore.block.multiplier 4 > hbase.hstore.blockingStoreFiles 16 (default was 4.. Could this be the > reason? But I don't see any IOExceptions in my log) > hbase.hregion.majorcompaction 691200000 (major compactions off) > hfile.block.cache.size 0.5 (default was 0.2) > > As for the logs, I do see a lot of > 2010-05-26 05:46:05,938 DEBUG > org.apache.hadoop.hbase.regionserver.CompactSplitThread: Compaction requested > for region DocData,32016328,1274284525421/910285966 because: Region has too > many store files > > But no IOExceptions.. And these compaction requests were turned off since > they hadnt crossed the ttl.. > > I will post the more relevant pieces of the log.. > Vidhya > > > On 5/26/10 10:19 AM, "Jonathan Gray" <[email protected]> wrote: > > If you can post the logs somewhere that would be very helpful. > > At 2000 regions/node you probably need to continue to increase the ulimit. > You might also need more handlers in the RS and DN. > >> -----Original Message----- >> From: Vidhyashankar Venkataraman [mailto:[email protected]] >> Sent: Wednesday, May 26, 2010 10:09 AM >> To: [email protected] >> Subject: Re: Effect of turning major compactions off.. >> >> No OOME or HDFS errors that I can see in the logs.. >> I turned major compaction on and restarted Hbase : now the RS's arent >> shutting down: Compactions are happening.. >> >> I had set the ulimit to 8000 a while back.. Should I increase it more >> then? (With the current setting, each region can have a max of around 4 >> open files if there are 2000 regions per node)... >> >> Let me also check the logs a little more carefully and get back to the >> forum.. >> >> Thank you >> Vidhya >> >> >> On 5/26/10 9:38 AM, "Jean-Daniel Cryans" <[email protected]> wrote: >> >> I'm pretty sure something else is going on. >> >> 1) What does it log when it shuts down? Zookeeper session timeout? >> OOME? HDFS errors? >> >> 2) Is your cluster meeting all the requirements? Especially the last >> bullet point? See >> http://*hadoop.apache.org/hbase/docs/r0.20.4/api/overview- >> summary.html#requirements >> >> J-D >> >> On Wed, May 26, 2010 at 9:07 AM, Vidhyashankar Venkataraman >> <[email protected]> wrote: >> > Are there any side effects to turning major compactions off, other >> than just a hit in the read performance? >> > >> > I was trying to merge a 120 Gig update (modify/insert/delete >> operations) into a 2 TB fully compacted Hbase table with 5 region >> servers using a map reduce job.. Each RS was serving around 2000 >> regions (256 MB max size)... Major compactions were turned off before >> the job started (by setting the compaction period very high to around 4 >> or 5 days).. >> > >> > As the job was going on, the region servers just shut down after the >> table reached near-100% fragmentation (as shown in the web interface).. >> On looking at the RS logs, I saw that there were compaction checks for >> each region which obviously didn't clear, and the RS's shut down soon >> after the checks.. I tried restarting the database after killing the >> map reduce job (still, with major compactions turned off).. The RS's >> shut down soon after booting up.. >> > >> > Is this expected? Even if the update files (the additional >> StoreFiles) per region get huge, won't the region get split on its own? >> > >> > Thank you >> > Vidhya >> > > > >
