WebPagetest Forums
impact of queue-size/server-load on results? - Printable Version

+- WebPagetest Forums (https://www.webpagetest.org/forums)
+-- Forum: WebPagetest (/forumdisplay.php?fid=7)
+--- Forum: Private Instances (/forumdisplay.php?fid=12)
+--- Thread: impact of queue-size/server-load on results? (/showthread.php?tid=11598)



impact of queue-size/server-load on results? - nilskuhn - 08-27-2012 08:42 PM

Hi Pat,

I've some agents which queues spilled over for some days. There were two reasons: Too much jobs and a very high i/o-load on the server so results were written back to wpt-server slowly. In browsers on agents sometimes I saw periods without any action for more than 10 secs (connected through vnc so these observations should be treated with caution...).

Now I have a changed page-loading-behaviour for some jobs running on these agents. The change occurred around the same time the queues spilled over. I am actually investigating whether I observe an effect of meaqsured pages or of my measurement-environment.

I don't think the queues or i/o-problem on server could have an impact on measurements on the agents. But you definately have a deeper knowledge of the codebase of agent-components: Can you rule out an impact of server i/o-load or queue-size on measurement results?

Regards Nils


RE: impact of queue-size/server-load on results? - pmeenan - 08-27-2012 10:46 PM

No, nothing on the server will impact any of the measurements on the client. It will impact how quickly the clients can process work since it will take longer to fetch a job and post the results but it will not impact the measurements themselves.

That is, as long as the server isn't also serving as a gateway router or DNS server for the test machines.


RE: impact of queue-size/server-load on results? - nilskuhn - 08-28-2012 02:14 AM

Thanks for your quick answer. That's what I expected.