In your case, likely you are hitting the blocking store files (hbase.hstore.blockingStoreFiles default:7) and/or hbase.hregion.memstore.block.multiplier - check out http://hbase.apache.org/book/config.files.html for more details on this configurations and how they affect your insert performance.
On ganglia, also check whether you have a compaction queue spiking during these timeouts. --Suraj On Thu, Jun 21, 2012 at 4:27 AM, Martin Alig <[email protected]> wrote: > Thank you for the suggestions. > > So I changed the setup and now have: > 1 Master running Namenode, SecondaryNamenode, ZK and the HMaster > 7 Slaves running Datanode and Regionserver > 2 Clients to insert data > > > What I forgot in my first post, that sometimes the clients even get a > SocketTimeOutException when inserting the data. (of course during that time > 0 inserts are done) > By looking at the logs, (I also turned on the gc logs) I see the following: > > Multiple consecutive entries like: > 2012-06-21 11:42:13,962 INFO org.apache.hadoop.hbase.regionserver.HRegion: > Blocking updates for 'IPC Server handler 6 on 60020' on region > usertable,user600,1340200683555.a45b03dd65a62afa676488921e47dbaa.: memstore > size 1.0g is >= than blocking 1.0g size > > Shortly after those entries, many entries like: > 2012-06-21 12:43:53,028 WARN org.apache.hadoop.ipc.HBaseServer: > (responseTooSlow): > {"processingtimems":35046,"call":"multi(org.apache.hadoop.hbase.client.MultiAction@2642a14d), > rpc version=1, client version=29, methodsFingerPrint=-1508511443","client":" > 10.110.129.12:54624 > ","starttimems":1340275397981,"queuetimems":0,"class":"HRegionServer","responsesize":0,"method":"multi"} > > Looking at the gc-logs, many entries like: > 2870.329: [GC 2870.330: [ParNew: 108450K->3401K(118016K), 0.0182570 secs] > 4184711K->4079843K(12569856K), 0.0183510 secs] [Times: user=0.24 sys=0.00, > real=0.01 secs] > > But always arround 0.01 secs - 0.04secs. > > And also from the gc-log: > 2696.013: [CMS-concurrent-sweep: 8.999/10.448 secs] [Times: user=46.93 > sys=2.24, real=10.45 secs] > > Is the 10.45 secs too long? > Or what exactly should I watch out for in the gc logs? > > > I also configured ganglia to have a look at some more metrics. Looking at > io_wait (which should matter concerning my question to the disks), I can > observe values between 10 % and 25 % on the regionserver. > Should that be lower? > > Btw. I'm using HBase 0.94 and Hadoop 1.0.3. > > > Thank you again. > > > Martin > > > > On Wed, Jun 20, 2012 at 7:04 PM, Dave Wang <[email protected]> wrote: > >> I'd also remove the DN and RS from the node running ZK, NN, etc. as you >> don't want heavweight processes on that node. >> >> - Dave >> >> On Wed, Jun 20, 2012 at 9:31 AM, Elliott Clark <[email protected] >> >wrote: >> >> > Basically without metrics on what's going on it's tough to know for sure. >> > >> > I would turn on GC logging and make sure that is not playing a part, get >> > metrics on IO while this is going on, and look through the logs to see >> what >> > is happening when you notice the pause. >> > >> > On Wed, Jun 20, 2012 at 6:39 AM, Martin Alig <[email protected]> >> > wrote: >> > >> > > Hi >> > > >> > > I'm doing some evaluations with HBase. The workload I'm facing is >> mainly >> > > insert-only. >> > > Currently I'm inserting 1KB rows, where 100Bytes go into one column. >> > > >> > > I have the following cluster machines at disposal: >> > > >> > > Intel Xeon L5520 2.26 Ghz (Nehalem, with HT enabled) >> > > 24 GiB Memory >> > > 1 GigE >> > > 2x 15k RPM Sas 73 GB (RAID1) >> > > >> > > I have 10 Nodes. >> > > The first node runs: >> > > >> > > Namenode, SecondaryNamenode, Datanode, HMaster, Zookeeper, and a >> > > RegionServer >> > > >> > > The other nodes run: >> > > >> > > Datanode and RegionServer >> > > >> > > >> > > Now running my test client and inserting rows, the throughput goes up >> to >> > > 150'000 inserts/sec. But then after some time the throughput drops down >> > to >> > > 0 inserts/sec for quite some time, before it goes up again. >> > > My assumption is, that it happens when the RegionServers start to write >> > the >> > > data from memory to the disks. I know, that the recommended hardware >> for >> > > HBase should contain multiple disks using JBOD or RAID 0. >> > > But at that point I am limited right now. >> > > >> > > I am just asking if in my hardware setup, the blocking periods are >> really >> > > caused by the non-optimal disk configuration. >> > > >> > > >> > > Thank you in advance for any suggestions. >> > > >> > > >> > > Martin >> > > >> > >>
