I Have apache2 running on Ubuntu 22. My Apache2 often getting killed by OOM. I have tried to get log and its showing something like this
> root@localhost:~# dmesg -e | grep -i kill [Mar15 03:00] shopping_cart
> invoked oom-killer:
> gfp_mask=0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0,
> oom_score_adj=0 [ +0.000004] oom_kill_process.cold+0xb/0x10 [
> +0.000001] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/system.slice/apache2.service,task=shopping_cart,pid=1676,uid=33
> [ +0.000012] Out of memory: Killed process 1676 (shopping_cart)
> total-vm:2398524kB, anon-rss:1834584kB, file-rss:0kB, shmem-rss:0kB,
> UID:33 pgtables:4044kB oom_score_adj:0 [ +4.614029] changelog.k2
> invoked oom-killer:
> gfp_mask=0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0,
> oom_score_adj=0 [ +0.000003] oom_kill_process.cold+0xb/0x10 [
> +0.000002] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/system.slice/apache2.service,task=changelog.k2,pid=6244,uid=33 [ +0.000016] Out of memory: Killed process 6244 (changelog.k2)
> total-vm:2398524kB, anon-rss:1856988kB, file-rss:0kB, shmem-rss:0kB,
> UID:33 pgtables:4048kB oom_score_adj:0
I am not getting idea with above logs.
when I check status of apache2 when its get killed I am getting something like this
root@localhost:~# sudo systemctl status apache2
× apache2.service - The Apache HTTP Server
Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
Active: failed (Result: oom-kill) since Wed 2023-03-15 03:00:07 UTC; 9min ago
Docs: https://httpd.apache.org/docs/2.4/
Process: 620 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
Process: 1746 ExecStop=/usr/sbin/apachectl graceful-stop (code=exited, status=0/SUCCESS)
Main PID: 736 (code=exited, status=0/SUCCESS)
CPU: 5min 4.064s
If I restart apache2, its start working fine but after some minutes, its again getting killed
I have tried apache2buddy and its showing me something like this
--------------------------------------------------------------------------------
### GENERAL FINDINGS & RECOMMENDATIONS ###
--------------------------------------------------------------------------------
Apache2buddy.pl report for server: localhost (45.33.10.196):
Settings considered for this report:
[ !! ] *** LOW UPTIME ***.
[ @@ ] The following recommendations may be misleading - apache has been restarted within the last 24 hours.
Your server's physical RAM: 3923 MB
Remaining Memory after other services considered: 3923 MB
Apache's MaxRequestWorkers directive: 115 <--------- Current Setting
Apache MPM Model: prefork
Largest Apache process (by memory): 40 MB
[ !! ] Your MaxRequestWorkers setting is too high.
Your recommended MaxRequestWorkers setting (based on available memory) is between 87 and 97. <-- Acceptable Range (90-100% of Remaining RAM)
Max potential memory usage: 4646 MB
Percentage of TOTAL RAM allocated to Apache: 118.43 %
Percentage of REMAINING RAM allocated to Apache: 118.43 %
--------------------------------------------------------------------------------
I have only changed mode_prefork like this
<IfModule mpm_prefork_module>
StartServers 2
MinSpareServers 5
MaxSpareServers 10
MaxRequestWorkers 115
MaxConnectionsPerChild 0
</IfModule>
I think its getting because of memory but I am not able to figure out which process of apache is consuming much memory and how I can solve it. I have tried htop and free but its not giving me any clue.
Let me know if someone here can help me for solve the puzzle.
Thanks!