Issues with mysqld, httpd, io r/w, cpu usage on CentOS 6.4
Hey all,
I'm having load times issues with a few sites I'm hosting on a dedicated server. I'll try to be as detailed as I can. I'm hosting a few sites (phpbb forum and some other simple sites) on a Centos 6.4, with 8GB of ram and a Quad Core processor. Two hard disks in software raid1. A few days ago I had to move the machine from one DC to another (the new one is better :) and since then the issues occurred. Currently I'm having slow loading times on almost all sites, mainly on the phpbb forum (forum is quite big - ~10.000 registered, 250.000 posts). My php version is 5.4.16, mysql is 5.5.32 and apache is 2.4.0. I've been researching almost everything on the machine and I found a few... lets say symptoms that might be causing this issue, but I don't know how to proceed in investigating them. I started monitoring memory usage, but there are no issues there. I started recieving the following reports: Code:
Time: Sat Sep 21 20:12:53 2013 +0300 I also monitored iotop and this caught my attention, although i have no idea what it means: Code:
958 be/3 root 0.00 B/s 31.26 K/s 0.00 % 99.99 % [jbd2/dm-2-8] Code:
<IfModule prefork.c> Code:
#Mysql Tunning Code:
::1 - - [21/Sep/2013:21:55:28 +0300] "OPTIONS * HTTP/1.0" 200 - "-" "Apache/2.2.15 (CentOS) (internal dummy connection)" Code:
tcp 0 0 my.ip:40100 my.ip:80 TIME_WAIT Code:
netstat -an|awk '/tcp/ {print $6}'|sort|uniq -c So I've been banging my head with this issue for the last 4-5 days and I'm at a dead end. No idea what to do or what is causing this, since no other changes were made except the migration. |
Do a netstat -nap and find out what process is having your server connect to itself and kill itself.
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A lot of these:
Code:
tcp 0 0 my.ip:41412 my.ip:http TIME_WAIT - Edit: Ok. So I could officially rule out an issue with the mysql database. I moved the most loaded DB on another server, loading times for the DB went from 7s to 0.36s, but the site (forum in my case) still loads extremely slow. |
Just to update.
A failing hard drive was the reason. Removed the old HDD's in raid1 and put a SSD. Now everything's perfect. |
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