[Solved] Sometimes Long Time to First Byte Time for the first request

[BITS]

(11-12-2013 07:24 PM)robzilla Wrote:  Could be poor disk performance. When you're testing the site and php-cgi takes roughly 28% of CPU, what's the CPU doing? Is it waiting for the disk? (%wa in top) You can use tools like hdparm (e.g. hdparm -tT /dev/vda1) or ioping to get a basic idea of disk performance, or something like fio for a more thorough analysis.

Thanks again for the answer. I did a few more tests with top again and also ioping. I also temporary deactivated the CDN.

The result was: http://www.webpagetest.org/result/131114...5129e3894/

But there was no high CPU usage and the %wa was all the time 0. The logging with top is a little bit complicated because you get the results only each second. There were also no high ms values via ioping. Sometimes about 15-20ms but that's nothing in comparison to a TTFB of about 1000 ms.

Do you have any other ideas?

Further question: Is there any possibility that this is not a server-side issue? If not, then I will probably change my provider.