So you have large RS and you have large regions. Your regions are huge relative to your RS memory heap. (Not ideal.)
You have slow drives (5400rpm) and you have 1GbE network. Do didn’t say how many drives per server. Under load, you will saturate your network with just 4 drives. (Give or take. Never tried 5400 RPM drives) So you hit one bandwidth bottleneck there. The other is the ratio of spindles to CPU. So if you have 4 drives and 8 cores… again under load, you’ll start to see an I/O bottleneck … On average, how many regions do you have per table per server? I’d consider shrinking your regions. Sometimes you need to dial back from 11 do a more reasonable listening level… ;-) HTH -Mike On Sep 8, 2014, at 8:23 AM, kiran <kiran.sarvabho...@gmail.com> wrote: > Hi Lars, > > Ours is a problem of I/O wait and network bandwidth increase around the > same time.... > > Lars, > > Sorry to say this... our's is a production cluster and we ideally should > never want a downtime... Also lars, we had very miserable experience while > upgrading from 0.92 to 0.94... There was a never a mention of change in > split policy in the release notes... and the policy was not ideal for our > cluster and it took us atleast a week to figure out that.... > > Our cluster runs on commodity hardware with big regions (5-10gb)... Region > sever mem is 10gb... > 2TB SATA Hard disks (5400 - 7200 rpm)... Internal network bandwidth is 1 gig > > So please suggest us any work around with 0.94.1.... > > > On Sun, Sep 7, 2014 at 8:42 AM, lars hofhansl <la...@apache.org> wrote: > >> Thinking about it again, if you ran into a HBASE-7336 you'd see high CPU >> load, but *not* IOWAIT. >> 0.94 is at 0.94.23, you should upgrade. A lot of fixes, improvements, and >> performance enhancements went in since 0.94.4. >> You can do a rolling upgrade straight to 0.94.23. >> >> With that out of the way, can you post a jstack of the processes that >> experience high wait times? >> >> -- Lars >> >> ------------------------------ >> *From:* kiran <kiran.sarvabho...@gmail.com> >> *To:* user@hbase.apache.org; lars hofhansl <la...@apache.org> >> *Sent:* Saturday, September 6, 2014 11:30 AM >> *Subject:* Re: HBase - Performance issue >> >> Lars, >> >> We are facing a similar situation on the similar cluster configuration... >> We are having high I/O wait percentages on some machines in our cluster... >> We have short circuit reads enabled but still we are facing the similar >> problem.. the cpu wait goes upto 50% also in some case while issuing scan >> commands with multiple threads.. Is there a work around other than applying >> the patch for 0.94.4 ?? >> >> Thanks >> Kiran >> >> >> On Thu, Apr 25, 2013 at 12:12 AM, lars hofhansl <la...@apache.org> wrote: >> >> You may have run into https://issues.apache.org/jira/browse/HBASE-7336 >> (which is in 0.94.4) >> (Although I had not observed this effect as much when short circuit reads >> are enabled) >> >> >> >> ----- Original Message ----- >> From: kzurek <kzu...@proximetry.pl> >> To: user@hbase.apache.org >> Cc: >> Sent: Wednesday, April 24, 2013 3:12 AM >> Subject: HBase - Performance issue >> >> The problem is that when I'm putting my data (multithreaded client, ~30MB/s >> traffic outgoing) into the cluster the load is equally spread over all >> RegionServer with 3.5% average CPU wait time (average CPU user: 51%). When >> I've added similar, mutlithreaded client that Scans for, let say, 100 last >> samples of randomly generated key from chosen time range, I'm getting high >> CPU wait time (20% and up) on two (or more if there is higher number of >> threads, default 10) random RegionServers. Therefore, machines that held >> those RS are getting very hot - one of the consequences is that number of >> store file is constantly increasing, up to the maximum limit. Rest of the >> RS >> are having 10-12% CPU wait time and everything seems to be OK (number of >> store files varies so they are being compacted and not increasing over >> time). Any ideas? Maybe I could prioritize writes over reads somehow? Is >> it >> possible? If so what would be the best way to that and where it should be >> placed - on the client or cluster side)? >> >> Cluster specification: >> HBase Version 0.94.2-cdh4.2.0 >> Hadoop Version 2.0.0-cdh4.2.0 >> There are 6xDataNodes (5xHDD for storing data), 1xMasterNodes >> Other settings: >> - Bloom filters (ROWCOL) set >> - Short circuit turned on >> - HDFS Block Size: 128MB >> - Java Heap Size of Namenode/Secondary Namenode in Bytes: 8 GiB >> - Java Heap Size of HBase RegionServer in Bytes: 12 GiB >> - Java Heap Size of HBase Master in Bytes: 4 GiB >> - Java Heap Size of DataNode in Bytes: 1 GiB (default) >> Number of regions per RegionServer: 19 (total 114 regions on 6 RS) >> Key design: <UUID><TIMESTAMP> -> UUID: 1-10M, TIMESTAMP: 1-N >> Table design: 1 column family with 20 columns of 8 bytes >> >> Get client: >> Multiple threads >> Each thread have its own tables instance with their Scanner. >> Each thread have its own range of UUIDs and randomly draws beginning of >> time >> range to build rowkey properly (see above). >> Each time Scan requests same amount of rows, but with random rowkey. >> >> >> >> >> >> -- >> View this message in context: >> http://apache-hbase.679495.n3.nabble.com/HBase-Performance-issue-tp4042836.html >> Sent from the HBase User mailing list archive at Nabble.com. >> >> >> >> >> -- >> Thank you >> Kiran Sarvabhotla >> >> -----Even a correct decision is wrong when it is taken late >> >> >> >> > > > -- > Thank you > Kiran Sarvabhotla > > -----Even a correct decision is wrong when it is taken late
