there an
inherent reason why the high CPU bound on continuous bulk writes can't be
improved?
Thanks for all the help,
Rishi
From: Jonathan Ellis
To: user@cassandra.apache.org
Sent: Fri, June 11, 2010 12:22:39 PM
Subject: Re: Cassandra Write Performance, CPU
, June 11, 2010 9:20:06 AM
> Subject: Re: Cassandra Write Performance, CPU usage
>
> Jonathan, while I agree with you re: this being an unusual load for the
> system, it is interesting that he's found at least one use-case where
> Cassandra is CPU-bound, not IO-bound. I
path.
Thanks,
Rishi
From: Mike Malone
To: user@cassandra.apache.org
Sent: Fri, June 11, 2010 9:20:06 AM
Subject: Re: Cassandra Write Performance, CPU usage
Jonathan, while I agree with you re: this being an unusual load for the system,
it is interesting that
Jonathan, while I agree with you re: this being an unusual load for the
system, it is interesting that he's found at least one use-case where
Cassandra is CPU-bound, not IO-bound. I'd definitely be interested in
learning what his critical path is and seeing if there's some low-hanging
fruit that ma
ntinuous
> bulk writes?
> Thanks for all the help,
> Rishi
>
> From: Jonathan Shook
> To: user@cassandra.apache.org
> Sent: Thu, June 10, 2010 7:39:24 PM
> Subject: Re: Cassandra Write Performance, CPU usage
>
> You are testing Cassandra in a way
To: user@cassandra.apache.org
Sent: Thu, June 10, 2010 7:39:24 PM
Subject: Re: Cassandra Write Performance, CPU usage
You are testing Cassandra in a way that it was not designed to be used.
Bandwidth to disk is not a meaningful example for nearly anything
except for filesystem benchmarking and things very nearl
You are testing Cassandra in a way that it was not designed to be used.
Bandwidth to disk is not a meaningful example for nearly anything
except for filesystem benchmarking and things very nearly the same as
filesystem benchmarking.
Unless the usage patterns of your application match your test data
Hi Rishi
The writes in Cassandra are not directly written to the Disk, they are
stored in memory and later on flushed to the disk. May be thats why you are
not getting much out of iostat. Cant say about high cpu usage.
___
Vineet Daniel
_
Hi
I am investigating Cassandra write performance and see very heavy CPU usage
from Cassandra. I have a single node Cassandra instance running on a dual core
(2.66 Ghz Intel ) Ubuntu 9.10 server. The writes to Cassandra are being
generated from the same server using BatchMutate(). The client ma
