[rrd-developers] [PATCH] rrdcached multiple writer threads

kevin brintnall kbrint at rufus.net
Mon Nov 10 15:15:34 CET 2008

On Mon, Nov 10, 2008 at 08:44:13AM -0000, Daniel.Pocock at barclayscapital.com wrote:
> > Now, rrdcached can have more simultaneous I/O requests into 
> > the kernel.
> > This may allow the kernel to re-order disk writes, resulting 
> > in better disk throughput.  In practice, throughput is 
> > increased by 2-3x.
> Before I integrate this with my own code, could you propose some tests
> that I should run with and without this code to measure the difference?

Let your rrdcached fill up with updates for at least "-w".  Then, issue a
FLUSHALL and see how long it takes the queue to get back to 0.

For best results, use "-z 0" and let the daemon fill for slightly less
than "-w"...  then the jitter shouldn't affect your value size per rrd.

 kevin brintnall =~ /kbrint at rufus.net/

> Regards,
> Daniel
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