[rrd-developers] rrdcached use corrupting RRD files (trunk)

[Bernard Li]

Hi Thorsten:

On Thu, Oct 21, 2010 at 7:12 PM, Thorsten von Eicken <tve at voneicken.com> wrote:

> As a separate data point, we're running over 100 rrdcached servers, each
> handling >30k tree nodes and receiving about 3k updates/sec, caching data
> for ~1 hour so updating files at ~20 updates/sec. Uptime in months without
> problem, never seen corruption (knock on wood). We're running 1.4 trunk
> revision r2092 (randomly picked) on Ubuntu 8.04 (used to run on CentOS 5.2,
> I believe). We're not seeing any memory leak and running stable at 800-900MB
> virtual / 500-600MB rss. We're using TCP sockets and doing updates, fetches
> and flushes. The command line we use is:
> /usr/bin/rrdcached -w 3600 -z 3600 -f 7200 -t 2 -a 128 -b /rrds/hosts -B -j
> /rrds/journal -p /var/run/rrdcached/rrdcached.pid -l 10.x.x.x:xxxx
> I'm not writing this to contradict you, I'm just wondering what could be
> different in your set-up that causes the problems. (Oh, that reminds me that
> the -a 128 made a huge difference for us around memory allocation
> performance.)

Can you elaborate on your setup a little bit more?  You mentioned that
you have 100 rrdcached servers running, is this for load balancing?
This looks like a very interesting setup.

Thanks!

Bernard