Hi Matt, this is something we haven't tested much, we were always running with about 32 regions which gave enough coverage for an even spread over all machines. I will run our tests with enough regions per server to cover all cores and get back to the ml
On Tue, Mar 20, 2012 at 1:55 AM, Matt Corgan <mcor...@hotpads.com> wrote: > I'd be curious to see what happens if you split the table into 1 region per > CPU core, so 24 cores * 11 servers = 264 regions. Each region has 1 > memstore which is a ConcurrentSkipListMap, and you're currently hitting > each CSLM with 8 cores which might be too contentious. Normally in > production you would want multiple memstores per CPU core. > > > On Mon, Mar 19, 2012 at 5:31 AM, Juhani Connolly <juha...@gmail.com> wrote: > >> Actually we did try running off two machines both running our own >> tests in parallel. Unfortunately the results were a split that results >> in the same total throughput. We also did the same thing with iperf >> running from each machine to another machine, indicating 800Mb >> additional throughput between each pair of machines. >> However we didn't try these tests very thoroughly so I will revisit >> them as soon as I get back to the office, thanks. >> >> On Mon, Mar 19, 2012 at 9:21 PM, Christian Schäfer <syrious3...@yahoo.de> >> wrote: >> > referring to my experiences I expect the client to be the bottleneck, >> too. >> > >> > So try to increase the count of client-machines (not client threads) >> each with its own unshared network interface. >> > >> > In my case I could double write throughput by doubling client machine >> count with a much smaller system than yours (5 machines, 4gigs RAM each). >> > >> > Good Luck >> > Chris >> > >> > >> > >> > ________________________________ >> > Von: Juhani Connolly <juha...@gmail.com> >> > An: user@hbase.apache.org >> > Gesendet: 13:02 Montag, 19.März 2012 >> > Betreff: Re: 0.92 and Read/writes not scaling >> > >> > I was concerned that may be the case too, which is why we ran the ycsb >> > tests in addition to our application specific and general performance >> > tests. checking profiles of the execution just showed the vast majority >> of >> > time spent waiting for responses. these were all run with 400 >> > threads(though we tried more/less just in case) >> > 2012/03/19 20:57 "Mingjian Deng" <koven2...@gmail.com>: >> > >> >> @Juhani: >> >> How many clients did you test? Maybe the bottleneck was client? >> >> >> >> 2012/3/19 Ramkrishna.S.Vasudevan <ramkrishna.vasude...@huawei.com> >> >> >> >> > Hi Juhani >> >> > >> >> > Can you tell more on how the regions are balanced? >> >> > Are you overloading only specific region server alone? >> >> > >> >> > Regards >> >> > Ram >> >> > >> >> > > -----Original Message----- >> >> > > From: Juhani Connolly [mailto:juha...@gmail.com] >> >> > > Sent: Monday, March 19, 2012 4:11 PM >> >> > > To: user@hbase.apache.org >> >> > > Subject: 0.92 and Read/writes not scaling >> >> > > >> >> > > Hi, >> >> > > >> >> > > We're running into a brick wall where our throughput numbers will >> not >> >> > > scale as we increase server counts both using custom inhouse tests >> and >> >> > > ycsb. >> >> > > >> >> > > We're using hbase 0.92 on hadoop 0.20.2(we also experience the same >> >> > > issues using 0.90 before switching our testing to this version). >> >> > > >> >> > > Our cluster consists of: >> >> > > - Namenode and hmaster on separate servers, 24 core, 64gb >> >> > > - up to 11 datanode/regionservers. 24 core, 64gb, 4 * 1tb disks(hope >> >> > > to get this changed) >> >> > > >> >> > > We have adjusted our gc settings, and mslabs: >> >> > > >> >> > > <property> >> >> > > <name>hbase.hregion.memstore.mslab.enabled</name> >> >> > > <value>true</value> >> >> > > </property> >> >> > > >> >> > > <property> >> >> > > <name>hbase.hregion.memstore.mslab.chunksize</name> >> >> > > <value>2097152</value> >> >> > > </property> >> >> > > >> >> > > <property> >> >> > > <name>hbase.hregion.memstore.mslab.max.allocation</name> >> >> > > <value>1024768</value> >> >> > > </property> >> >> > > >> >> > > hdfs xceivers is set to 8192 >> >> > > >> >> > > We've experimented with a variety of handler counts for namenode, >> >> > > datanodes and regionservers with no changes in throughput. >> >> > > >> >> > > For testing with ycsb, we do the following each time(with nothing >> else >> >> > > using the cluster): >> >> > > - truncate test table >> >> > > - add a small amount of data, then split the table into 32 regions >> and >> >> > > call balancer from the shell. >> >> > > - load 10m rows >> >> > > - do a 1:2:7 insert:update:read test with 10million rows (64k/sec) >> >> > > - do a 5:5 insert:update test with 10 million rows (23k/sec) >> >> > > - do a pure read test with 10 million rows (75k/sec) >> >> > > >> >> > > We have observed ganglia, iostat -d -x, iptraf, top, dstat and a >> >> > > variety of other diagnostic tools and network/io/cpu/memory as >> >> > > bottlenecks seem highly unlikely as none of them are ever seriously >> >> > > taxed. This leave me to assume this is some kind of locking issue? >> >> > > Delaying WAL flushes gives a small throughput bump but it doesn't >> >> > > scale. >> >> > > >> >> > > There also doesn't seem to be many figures around to compare ours >> to. >> >> > > We can get our throughput numbers higher with tricks like not >> writing >> >> > > the WAL or delaying flushes, batching requests, but nothing seems to >> >> > > scale with additional slaves. >> >> > > Could anyone provide guidance as to what may be preventing >> throughput >> >> > > figures from scaling as we increase our slave count? >> >> > >> >> > >> >> >>
