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:giorgi.jvari...@gmail.com] Sent: Tuesday, June 19, 2012 7:26 PM To: user@hbase.apache.org 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 <anoo...@huawei.com> 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 [giorgi.jvari...@gmail.com] Sent: Monday, June 18, 2012 7:28 PM To: user@hbase.apache.org 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
