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From Heath Oderman <he...@526valley.com>
Subject Re: New User: OSX vs. Debian on Cassandra 0.5.0 with Thrift
Date Thu, 15 Apr 2010 17:53:39 GMT
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 <heath@526valley.com> wrote:

> Thanks Jonathan, I'll check this out right away.
>
>
> On Thu, Apr 15, 2010 at 1:32 PM, Jonathan Ellis <jbellis@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 <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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