I am using /server-status to monitor the Apache processes. When starting they look like this:
_____W_K__K____________C_K________C_____________W_..............
................................................................
................................................................
But after few hours of running look like this:
R_KCR___KR__RKRR_RRRKRRRRRRKRR_RRCK____R_RRRR_RRRKRRRKRRRRRRRRR_
R_RRRR_R.RR.R_R.R_R..CKRRRRW.K_RCRKRR_R_.._R._.RK_KRK_.RRR.KK_.R
..RR............................................................
There is too many "Read" (R) status which took a long time and I don't know what they do, because they even have no requests. (Mention that there are additional "." statuses which I skipped from the example above, in total I have 2000 positions available.) In the process list I have approx 40 "R" processes like this one:
Srv PID Acc M CPU SS Req Conn Child Slot Client VHost Request
15-2 21291 0/37/11158 R 0.03 7468 2 0.0 1.93 198.35 82.78.95.105
The report's header look like this:
Server Version: Apache/2.4.10 (Debian) mod_fcgid/2.3.9 OpenSSL/1.0.1t
Server MPM: prefork
Server Built: Sep 15 2016 20:44:43
Current Time: Thursday, 12-Jan-2017 08:38:46 EET
Restart Time: Wednesday, 11-Jan-2017 00:51:18 EET
Parent Server Config. Generation: 3
Parent Server MPM Generation: 2
Server uptime: 1 day 7 hours 47 minutes 27 seconds
Server load: 0.34 0.35 0.39
Total accesses: 1599556 - Total Traffic: 29.9 GB
CPU Usage: u18.87 s6.81 cu0 cs0 - .0224% CPU load
14 requests/sec - 274.0 kB/second - 19.6 kB/request
90 requests currently being processed, 27 idle workers
I have a private server with: 4X3.6GHZ Xeon processor, 2X512 GB SSD, 32 GB memory, Debian 3.16.36-1, Apache 2.4.10, PHP 5.6.29, mod_fcgid, php-fpm, php5-cgi, prefork.
Some of my apache2.conf settings:
Timeout 14400
KeepAlive On
MaxKeepAliveRequests 1000
KeepAliveTimeout 3
HostnameLookups Off
My mpm_prefork.conf settings:
<IfModule mpm_prefork_module>
StartServers 50
MinSpareServers 25
MaxSpareServers 50
ServerLimit 2000
MaxRequestWorkers 2000
MaxConnectionsPerChild 1000
</IfModule>
Some of my fcgid.conf settings:
FcgidMaxRequestLen 1073741824
FcgidOutputBufferSize 1073741824
FcgidMaxProcesses 200
FcgidMaxProcessesPerClass 100
FcgidMinProcessesPerClass 0
FcgidProcessLifeTime 30
FcgidConnectTimeout 30
FcgidIOTimeout 14400
FcgidBusyTimeout 14400
FcgidIdleTimeout 3
FcgidIdleScanInterval 1
I have some long runing cronjobs in the servers, this is why I need that big "14400" (=4 hours) timeout on Apache and PHP processes.
Questions:
Update 1:
A have modified the timeouts to 7200 (=2 hours), this is the minimum for me to can run my cronjobs. However I did not have problems with my cronjobs.
FcgidIOTimeout 7200
FcgidBusyTimeout 7200
Also for Apache:
Timeout 7200
Based on PHP and mod_fcgid: ap_pass_brigade failed in handle_request_ipc function I did this:
FcgidOutputBufferSize 0
Based on mod_fcgid: ap_pass_brigade failed in handle_request function I did this:
FcgidMaxRequestsPerProcess 500
After few hours the server stopped responding:
Service Unavailable: The server is temporarily unable to service your request due to maintanance downtime or capacity problems. Please try again later.
In the logs I found some erros like this two:
[fcgid:warn] (104)Connection reset by peer: mod_fcgid: ap_pass_brigade failed in handle_request_ipc function
[fcgid:warn] (32)Broken pipe: mod_fcgid: ap_pass_brigade failed in handle_request_ipc function
And a bunch of like this (maybe for each requests):
[fcgid:warn] mod_fcgid: too much processes, please increase FCGID_MAX_APPLICATION
Questions 2:
Problem solved.
The solution was to lower the Apache's Timeout value to a number like 15. As I realized for running a long PHP script (even for hours) do not need to this timeout to be hight, it's enought that the PHP's max_execution_time to be big enought.
Update
I have also upgraded to PHP 7.1 with FastCGI under PHP-FPM, and I have changed the Apache's MPM mode to event as esra-s suggested, and it runs like hell. Many thanks!