Issue FCGI handler always faster than FPM?!?

[lanix343]

Dear Pleskians,

I've been puzzled by this phenomenon for quite some time and I just can't find a solution to it.

I'm running a dedicated managed Plesk server with ample resources and when the FCGI handler is selected all the websites using that handler run considerably faster than under FPM handler.

Notabily the TTFB in the front-end and the wordpress backend is twice as fast using the FCGI handler as opposed to FPM. I've tried many different nginx and php configurations to remedy this issue to no success.

What is even more puzzling is that when I switch the handler from FCGI to FPM on one specific site that paticular site will perform just as fast as FCGI until any other handler is switches for any other site on the server. The fast performing FPM site then becomes slow again TTFB from 300ms to 1s. It seems that online one of the many FPM handler sites can be fast while the performance rotates randomly when handler changes are made.

Currently about 50 WordPress Websites are hosted on the sever. There is not a whole lot of traffic on most of the sites. 200-300 Visits per day per Site. The above described behavior can be replicated across the board. Should FPM not be faster than FCGI?

Here are the server specs:

4x Intel Xeon Gold 6144
16 vCores 4,2 GHz
128 GB DDR4 RAM
3000 GB NVMe SSD
Virtuozzo 7 Hypervisor


Does anyone have an idea on how to fix this issue? What information would you need to be able to say more about the issue?

Thanks

Thomas

 

[lanix343]

Here is a visualization of the issue on one domain. TTFB doubles when switched to FPM

 

[lanix343]

Just tried the FPM nginx only option and I get the same problem. The performance seems to degrade over time (10 minutes or so).... with FCGI Serverd by Apache the performance remains stable... is it an option to switch all 50 Sites to FCGI? What are the disadvantages of this?

 

[lanix343]

Guys, this issue is really frustrating me. I am willing to pay someone to help me solve it. Please help.

 

[IgorG]

I am willing to pay someone to help me solve it. Please help.

How to get support directly from Plesk?