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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: New User: OSX vs. Debian on Cassandra 0.5.0 with Thrift
Date Thu, 15 Apr 2010 17:32:57 GMT
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 <heath@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.
>
>

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