Sites are suddenly painfully slow

[Ade]

Hi all,
I just noticed that all sites are painfully slow. The overall server load is very low:

The server still has 20GB of memory free, a reboot has fixed the issue just for a couple of minutes, top isn’t showing any specific process using most of the resources what else can I try?

Do you recommend installing zabbix et similia? Any guide for those?

Regards,
Ade

[sahsanu]

Hi @Ade,

The first thing you should do is to check access and error logs for your web server.

You can check the network load using some software like nload or bmon.

You could also check the number of connections to your server:

Note: netstat is part of package net-tools

netstat -ntu | awk '{print $5}' | cut -s -d ':' -f1 -s | sort | uniq -c | sort -n -k1 -r

Also check if your disk is performing as usual using hdparm.

hdparm -t /dev/YourDiskDevice

Check whether the iowait is high using sar command (sar is part of package sysstat):

sar 1 25

[Ade]

Hey @sahsanu thank you very much, very useful!
As it came it went away but I will test these commands next time the issue arises.

Do you use/recommend any specific monitoring system?

[sahsanu]

You are welcome.

@Ade

Do you use/recommend any specific monitoring system?

I should but I don’t

[Ade]

ahaha