One region server has 0 hits and the UI shows requests=0. What can I do to up the hit ratio here?
2010-09-04 03:35:22,355 DEBUG org.apache.hadoop.hbase.io.hfile.LruBlockCache: Cache Stats: Sizes: Total=19.647781MB (20602192), Free=2375.365MB (2490750640), Max=2395.0127MB (2511352832), Counts: Blocks=0, Access=0, Hit=0, Miss=0, Evictions=0, Evicted=0, Ratios: Hit Ratio=NaN%, Miss Ratio=NaN%, Evicted/Run=NaN The other two show: 2010-09-04 03:36:32,287 INFO org.apache.hadoop.hbase.regionserver.Store: Started compaction of 3 file(s) in info of .META.,,1 into /hbase/.META./compaction.dir/1028785192, seqid=164345389 2010-09-04 03:36:34,528 INFO org.apache.hadoop.hbase.regionserver.Store: Completed compaction of 3 file(s) in info of .META.,,1; new storefile is hdfs://tnsardev01.vip.ebay.com:8020/hbase/.META./1028785192/info/7893004816035348521; store size is 15.5m 2010-09-04 03:36:34,540 INFO org.apache.hadoop.hbase.regionserver.HRegion: compaction completed on region .META.,,1 in 2sec 2010-09-04 03:37:22,264 DEBUG org.apache.hadoop.hbase.io.hfile.LruBlockCache: Cache Stats: Sizes: Total=1488.8961MB (1561220736), Free=906.1166MB (950132096), Max=2395.0127MB (2511352832), Counts: Blocks=23374, Access=587213, Hit=559712, Miss=27501, Evictions=0, Evicted=0, Ratios: Hit Ratio=95.31669020652771%, Miss Ratio=4.68330904841423%, Evicted/Run=NaN 2010-09-04 03:37:35,936 DEBUG org.apache.hadoop.hbase.regionserver.HRegion: Flush requested on .META.,,1 2010-09-04 03:37:35,936 DEBUG org.apache.hadoop.hbase.regionserver.HRegion: Started memstore flush for region .META.,,1. Current region memstore size 16.4k 2010-09-04 03:37:35,936 DEBUG org.apache.hadoop.hbase.regionserver.HRegion: Finished snapshotting, commencing flushing stores 2010-09-04 03:37:36,031 INFO org.apache.hadoop.hbase.regionserver.Store: Added hdfs://tnsardev01.vip.ebay.com:8020/hbase/.META./1028785192/info/3977367354689552666, entries=78, sequenceid=164345468, memsize=16.4k, filesize=6.7k to .META.,,1 2010-09-04 03:37:36,032 DEBUG org.apache.hadoop.hbase.regionserver.HRegion: Caches flushed, doing commit now (which includes update scanners) 2010-09-04 03:37:36,064 INFO org.apache.hadoop.hbase.regionserver.HRegion: Finished memstore flush of ~16.4k for region .META.,,1 in 128ms, sequence id=164345468, compaction requested=false And 2010-09-04 03:36:20,864 DEBUG org.apache.hadoop.hbase.io.hfile.LruBlockCache: Cache Stats: Sizes: Total=516.6745MB (541772472), Free=1878.3383MB (1969580360), Max=2395.0127MB (2511352832), Counts: Blocks=7909, Access=134626, Hit=126717, Miss=7909, Evictions=0, Evicted=0, Ratios: Hit Ratio=94.1252052783966%, Miss Ratio=5.874793976545334%, Evicted/Run=NaN 2010-09-04 03:36:31,150 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: MSG_REGION_OPEN: table1,,1282609302542 2010-09-04 03:36:31,150 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Worker: MSG_REGION_OPEN: table1,,1282609302542 2010-09-04 03:36:32,170 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: MSG_REGION_OPEN: table2,,1282610731451 2010-09-04 03:36:32,170 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Worker: MSG_REGION_OPEN: DMSCORE,,1282610731451 ... Goes on to this again and again How can I interpret these logs? Are these expected log outputs? Each regionserver has 4G heap, 75 regionserver handler counts and 0.6 block cache. The performance of random reads is very low. -Avani -----Original Message----- From: Ted Yu [mailto:[email protected]] Sent: Saturday, August 28, 2010 7:22 AM To: [email protected] Subject: Re: regionserver skew For #1, you can check HBase master UI at the bottom of which is a table listing number of regions hosted on each RS and heap consumption information. On Fri, Aug 27, 2010 at 6:28 PM, Sharma, Avani <[email protected]> wrote: > I have a few questions related to reading from hbase - > > > > 1. How can I detect a regionserver skew. In other words, one > regionserver is being hit more than the others ? > > When I look at the master log, it states > "org.apache.hadoop.hbase.master.ServerManager: 3 region servers, 0 dead, > average load 23.666666666666668" > > Does that mean that the load is balanced? And in case it is not, do I need > to redesign or reload my Hbase table ? any other options ? > > > 2. Is it okay to have stargate running on more than one node in the > cluster? I am using stargate and libcurl to read from Hbase and to speed > this up, may be hitting different stargate servers could help ? Any cons to > this? > > > > 3. Is there a way I can get more than one version of a row via > stargate ? I tried the url with "?v=2" in the end, but it did not work. > > Thanks, > Avani Sharma > > >
