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. > >
