Apache2 seems busy

Question

I have an Ubuntu 14.04.4 LTS server running Apache/2.4.7 and my error.log file is frequently getting this kind of message below:

[Thu Sep 01 19:45:40.571637 2016] [mpm_prefork:info] [pid 1696] AH00162: server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers), spawning 8 children, there are 3 idle, and 17 total children
[Thu Sep 01 19:47:03.699939 2016] [mpm_prefork:info] [pid 1696] AH00162: server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers), spawning 8 children, there are 4 idle, and 17 total children
[Thu Sep 01 19:48:35.856132 2016] [mpm_prefork:info] [pid 1696] AH00162: server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers), spawning 8 children, there are 2 idle, and 20 total children

I've already changed my apache2.conf and it looks like the following:

# prefork MPM
# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# MaxRequestWorkers: maximum number of server processes allowed to start (was: MaxClients)
# MaxConnectionsPerChild: maximum number of requests a server process serves (was: MaxRequestsPerChild)
<IfModule mpm_prefork_module>
    StartServers           100
    MinSpareServers        30
    MaxSpareServers        60
    ServerLimit            400
    MaxRequestWorkers      400
    MaxConnectionsPerChild 10000
</IfModule>

After restarting apache2, errors still remains the same.

My server isn't running out of memory neither CPU usage (htop output looks pretty fine).

Also, I got those results when executing netstat and ps:

ubuntu@php-app1:~$ sudo netstat -pant | grep -c ESTABLISHED

18

ubuntu@php-app1:~$ ps -ef | grep -ic apache2

17

Any help, please? Thanks a lot for your patience and support.

score 1 · Answer 1 · answered Sep 05 '16 at 21:01

The logs and shell output are not consistent with that apache configuration being in effect. The directive

MinSpareServers 30

would mean that there were always at least 30 apache children running at a time and as long as that number is larger than the number that needs to get spawned, that error message won't appear.

Confirm that the config file being edited is in fact the one in use by the apache, try for instance

httpd -t -D DUMP_INCLUDES

or check for the use of a -f parameter, specifying a different parent configuration file.

+1 for config not matching log entries. But for the sake of accuracy, the hysteresis model (throttled forking, delayed reaping) can mean that (with *very* unusual) traffic patterns, the system can run out of idle processes. This probably isn't the case here though. — symcbean, Sep 05 '16 at 21:24

Apache2 seems busy

1 Answers1