Beginners performance problem

Sean Cribbs sean at basho.com
Fri Feb 22 10:28:32 EST 2013


Given iostat says ~10% utilization, I would suggest increasing the
concurrency of your writes. It's obviously not using up the capacity
of the disk, your bottleneck is elsewhere. 2MB/sec is low for any
commodity hardware.

On Fri, Feb 22, 2013 at 9:21 AM, Lars J. Nilsson
<lars.j.nilsson at cubeia.com> wrote:
> Hi all,
>
> I'm micro-testing a simple update pattern (key + short json document) on my
> local workstation (8 core intel CPU, 8 gig of RAM, 10K disk) to get baseline
> before moving to cluster on AWS. With Riak I get about 60 mods/s before
> maxing out (as compared to approx 3000 mods/s on a vanilla MySQL using
> exactly the same code).
>
> It feels like I must be doing something hideously wrong. (For the record,
> I'm a decent Java programmer but a riak/erlang n00b).
>
> Riak is installed via a vanilla Ununtu 12.04 package as described in the
> docs. The test ran on the same disk as the mentioned MySQL test. The same
> Java code was doing both tests (just a DAO swapped).
>
> The bucket was using n_val = 1.
>
> The problem seems to be in high disk-writing, despite the low load. Here's
> what iostat says during the run:
>
> [...]
> wrqm/s : 434.50
> w/s: 182.90
> wkB/s: 2618.00
> avgrq-sz: 28.63
> [...]
> %util: 10.60
>
> Which seems to be too much considering the small load (the stored JSON blobs
> are roughly 1K each).
>
> I'm using the official PB Java client.
>
> This is an evaluation for a customer. Any hint of what I'm missing or what
> the problem could be would be appreciated.
>
> Cheers
> /Lars J. Nilsson
> Executive VP, Cubeia Ltd
> +46 (0) 704 / 10 69 53
>
> _______________________________________________
> riak-users mailing list
> riak-users at lists.basho.com
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>



-- 
Sean Cribbs <sean at basho.com>
Software Engineer
Basho Technologies, Inc.
http://basho.com/




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