incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
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 17:57:57 GMT
What kind of numbers do you get from contrib/py_stress?

(that's located somewhere else in 0.5, but you should really be using
0.6 anyway.)

On Thu, Apr 15, 2010 at 12:53 PM, Heath Oderman <heath@526valley.com> wrote:
> 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.
>>> >
>>> >
>>
>
>

Mime
View raw message