So checking it out quickly: vmstat -
Never swaps. si and so stay at 0 during the load. iostat -x the %util never climbs above 0.00, but the avgrg-sz jumps bewteen samples from 0 - 30 - 90 - 0 (5 second intervals) top shows the cpu barely working and mem utilization is below 20%. Still slow. :( Thanks for the suggestions. In your article on your blog it'd be awesome to include some implications, like "avgrg-sz over 250 may mean XXX" Even if it's utterly hardware and system dependent it'd give a guy like me an idea if what I was seeing was bad or good. :D Thanks again, Heath On Thu, Apr 15, 2010 at 1:34 PM, Heath Oderman <he...@526valley.com> wrote: > Thanks Jonathan, I'll check this out right away. > > > On Thu, Apr 15, 2010 at 1:32 PM, Jonathan Ellis <jbel...@gmail.com> wrote: > >> You're right, to get those numbers on debian something is very wrong. >> >> Have you looked at >> http://spyced.blogspot.com/2010/01/linux-performance-basics.html ? >> What is the bottleneck on the linux machines? >> >> With the kind of speed you are seeing I wouldn't be surprised if it is >> swapping. >> >> -Jonathan >> >> On Tue, Apr 13, 2010 at 11:38 PM, Heath Oderman <he...@526valley.com> >> wrote: >> > Hi, >> > I wrote a few days ago and got a few good suggestions. I'm still seeing >> > dramatic differences between Cassandra 0.5.0 on OSX vs. Debian Linux. >> > I've tried on Debian with the Sun JRE and the Open JDK with nearly >> identical >> > results. I've tried a mix of hardware. >> > Attached are some graphs I've produced of my results which show that in >> OSX, >> > Cassandra takes longer with a greater load but is wicked fast >> (expected). >> > In the SunJDK or Open JDK on Debian I get amazingly consistent time >> taken to >> > do the writes, regardless of the load and the times are always >> ridiculously >> > high. It's insanely slow. >> > I genuinely believe that I must be doing something very wrong in my >> Debian >> > setups, but they are all vanilla installs, both 64 bit and 32 bit >> machines, >> > 64bit and 32 bit installs. Cassandra packs taken from >> > http://www.apache.org/dist/cassandra/debian. >> > I am using Thrift, and I'm using a c# client because that's how I intend >> to >> > actually use Cassandra and it seems pretty sensible. >> > An example of what I'm seeing is: >> > 5 Threads Each writing 100,000 Simple Entries >> > OSX: 1 min 16 seconds ~ 6515 Entries / second >> > Debian: 1 hour 15 seconds ~ 138 Records / second >> > 15 Threads Each writing 100,000 Simple Entries >> > OSX: 2min 30 seconds seconds writing ~10,000 Entries / second >> > Debian: 1 hour 1.5 minutes ~406 Entries / second >> > 20 Threads Each Writing 100,000 Simple Entries >> > OSX: 3min 19 seconds ~ 10,050 Entries / second >> > Debian: 1 hour 20 seconds ~ 492 Entries / second >> > If anyone has any suggestions or pointers I'd be glad to hear them. >> > Thanks, >> > Stu >> > Attached: >> > 1. CassLoadTesting.ods (all my results and graphs in OpenOffice format >> > downloaded from Google Docs) >> > 2. OSX Records per Second - a graph of how many entries get written per >> > second for 10,000 & 100,000 entries as thread count is increased in OSX. >> > 3. Open JDK Records per Second - the same graph but of Open JDK on >> Debian >> > 4. Open JDK Total Time By Thread - the total time taken from test start >> to >> > finish (all threads completed) to write 10,000 & 100,000 entries as >> thread >> > count is increased in Debian with Open JDK >> > 5. OSX Total time by Thread - same as 4, but for OSX. >> > >> > >> > >
