Ok found the cause, does seem FETCH support was added rrdcached in 1.5
and Nagle wasn't being disabled on the network socket so every request
was seeing a 0.1 second delay in completion.
PR to fix can be found here: https://github.com/oetiker/rrdtool-1.x/pull/706
Testing here showed this dropped our test of 862 fetches from 91.338
seconds to 0.335 seconds :)
Regards
Steve
On 10/04/2016 01:43, Steven Hartland wrote:
We updated to rrdtool 1.5.5 from 1.4 the other day and since then have
noticed dramatic slow down.
I just did some benchmarks and talking to rrdcached over a network
socket (same host) to do 862 fetches took 91.388106 seconds e.g.
FETCH 351918.rrd AVERAGE 1460244557 1460244917
The same over local unix socket took 0.097147 seconds so it looks like
there's been a major performance regression in 1.5 from 1.4?
When we initially updated the client before our rrdcached server we
did see errors with:
rrdcached: Unknown command: FETCH
So I'm wondering if rrdcached FETCH is new 1.5 hence the issue.
Previously we were running: rrdtool 1.4.8
Anyone got any ideas?
Regards
Steve
_______________________________________________
rrd-users mailing list
rrd-users@lists.oetiker.ch
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
