Hi I have vanilla CDH4 setup haven't changed any config.
I don't think that regionserver is getting hotspotted, because I'm using auto-incremented and then reversed ids so it should be evenly distributed across the regionservers. Regards, Giorgi On Tue, Jun 19, 2012 at 6:22 PM, Ramkrishna.S.Vasudevan < [email protected]> wrote: > And is your regionserver getting hotspotted? Like all your requests are > targeted to one particular RegionServer or to one particular region alone? > > > > Regards > > Ram > > > > From: Giorgi Jvaridze [mailto:[email protected]] > Sent: Tuesday, June 19, 2012 7:26 PM > To: [email protected] > Subject: Re: Decreasing write speed over time > > > > Hi thanks for answer, > > > > I've attached image of the chart. > > Write performance is going down by the time. and never goes up. > > As you can see on chart there are spikes but beside that generally write > performance goes down over time. > > > > Thanks. > > Giorgi > > On Tue, Jun 19, 2012 at 3:21 PM, Anoop Sam John <[email protected]> > wrote: > > Hi > Sorry I was not able to access your chart of put perf. Is it like the > performance gradually coming down and at some point again getting better > all of a sudden? [some spikes in graph] > It may be because of HBASE-3484 > > You can check the memstore size that u have given and see whether the > spikes coming at the memstore flush time and then again perf going down > gradually... > > -Anoop- > __________ > From: Giorgi Jvaridze [[email protected]] > Sent: Monday, June 18, 2012 7:28 PM > To: [email protected] > Subject: Decreasing write speed over time > > > Hello list, > > I have Hbase (CDH4) setup of a master and 4 region servers (8 core 2.0GHz, > 6GB of RAM and 6 100GB disks per data node). All of them are virtual > machines. > > I'm writing into a table using single thread w/ auto flush off. > Ids are increased by one and then reversed. Data is a string with average > length 150 chars. > > I'm measuring time needed for writing one million rows. At first I got > quite good results, it could write about 40-50K rows in a second but after > time this speed decreased. > I have a chart showing how It has been decreased by the time and data got > bigger. At the end of chart it's about 2 billion rows inserted. > > http://i.minus.com/iRFtEoVJVsFso.png > > Is this expected behavior for this kind of setup or something could went > wrong and I should check it up? > > Thanks! > > Giorgi > > > >
