Odd. Mind thread dumping the regionserver a few times and pastebining it during a compaction so we can see where its spending time? (Your compaction numbers are bad).
St.Ack On Fri, Jan 7, 2011 at 11:07 PM, Chris Tarnas <[email protected]> wrote: > Thanks in advance for any help. I've been quite pleased with Hbase for this > current project and until this problem it has worked quite well. > > Test cluster setup is CDH3b3 on a 7 nodes: > 5 data nodes with 48GB RAM, 8 cores, 4 disks, > 2 masters with 8 cores, 2 disks 24GB RAM for master/zookeeper/namenode > > My hbase.hregion.max.filesize is set to 1GB, ulimit files to 32k and xceivers > to 4096, hbase heap is at 8GB. > > I'm testing out using GZ compression on two tables, each is currently still > only one region. My tests runs fine when compression is off so this is > definitely related to compression. When I start loading data (via thrift, > many clients) it loads great for a while then the region servers slow to > crawl. When this happens the two regionservers that are hosting the tables > use ~ 110-160% CPU and block writes. One regionserver has occasional bursts > of activity but mostly is very repetitive, here is a sample of the log: > > http://pastebin.com/WSc8aZFQ > > The other active regionserver looks to be continuously compacting: > > http://pastebin.com/3ifVKaX2 > > > The master log is quite boring with this being repeated: > > 2011-01-08 00:48:58,419 INFO org.apache.hadoop.hbase.master.BaseScanner: > RegionManager.rootScanner scanning meta region {server: 10.56.24.8:60020, > regionname: -ROOT-,,0.70236052, startKey: <>} > 2011-01-08 00:48:58,424 INFO org.apache.hadoop.hbase.master.BaseScanner: > RegionManager.rootScanner scan of 1 row(s) of meta region {server: > 10.56.24.8:60020, regionname: -ROOT-,,0.70236052, startKey: <>} complete > 2011-01-08 00:48:58,444 INFO org.apache.hadoop.hbase.master.ServerManager: 5 > region servers, 0 dead, average load 1.6 > 2011-01-08 00:49:04,810 INFO org.apache.hadoop.hbase.master.BaseScanner: > RegionManager.metaScanner scanning meta region {server: 10.56.24.7:60020, > regionname: .META.,,1.1028785192, startKey: <>} > 2011-01-08 00:49:04,820 INFO org.apache.hadoop.hbase.master.BaseScanner: > RegionManager.metaScanner scan of 6 row(s) of meta region {server: > 10.56.24.7:60020, regionname: .META.,,1.1028785192, startKey: <>} complete > 2011-01-08 00:49:04,820 INFO org.apache.hadoop.hbase.master.BaseScanner: All > 1 .META. region(s) scanned > > > At this point loading slows to a trickle (requests are 0 in the web ui), I > can see infrequent bursts of loading but very small amounts. Each table only > has one region (and there are only two other tables, each also with only one > region). > > I've compiled and tested the native GZ compression codecs on the nodes and > the nodes have plenty of CPU, IO and memory available and no swapping. Any > suggestions? Please let me know if you need any other info. > > thanks! > -chris
