Resolved intermittent 502 errors on sites

[helpchrisplz]

Hi all.

So We keep getting random 502 errors on all our sites that we host using plesk 12.5
This happens multiple times throughout the day and normally lasts for about 10 - 15 mins at a time and then just starts working again.

Please can anyone advise me on what to do about it?
This is what i have done last time it went down:

ps -efww
and this is the output:
https://www.surgemarketingsolutions.co.uk/temp/ssh_output2.txt

I then tried this to make it come back online using the following but it didn't do much but it finally did come back after 6 mins or so:

[root@surge ~]# service nginx stop
[root@surge ~]# service httpd restart [ OK ]
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
[root@surge ~]# apachectl graceful
[root@surge ~]# service nginx restart
Starting nginx: [ OK ]
[root@surge ~]# /etc/init.d/httpd status
httpd (pid 9159) is running...
[root@surge ~]# /etc/init.d/httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
[root@surge ~]#

 

[Ivo]

Hello

What do logs of websites say?

/var/www/vhosts/name_of_website/errror_log ?

 

[helpchrisplz]

ok probably found the problem:
Fail to ban was bannign apache
2016-12-12 14:11:16,058 fail2ban.actions [10960]: NOTICE [plesk-apache] Ban 88.208.205.107

Added 88.208.205.107 to the whitelist.


I expect that this has only become an issue recently now that we have a lot more sites so when there is an influx in the amount of traffic that apache needs to deal with then it must have been going over the failtoban limit.

Hopefully thats it.

 

[UFHH01]

Hi helpchrisplz,

pls. be informed, that you should ALWAYS whitelist "localhost" ( 127.0.0.1/8 ) and ALL your server - IPs, when you use Fail2Ban on your server - it has got nothing to do with a "Fail2Ban - limit", it is an essential setting. Pls. consider to read official documentations.

[DEFAULT]
...
ignoreip =
...

Pls. see as well:

=> http://www.fail2ban.org/wiki/index.php/Whitelist / => Protection Against Brute Force Attacks (Fail2Ban) ( Plesk 12.5 - online documentation - Administrator's Guide )
( or => http://lmgtfy.com/?q=%22%5BDEFAULT%5D%22+%22ignoreip+%3D%22+site%3A+fail2ban.org )​

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