Last few days i found the Free Hosting Server (AMD 2400, 512 MB RAM, 80 GB HDD) getting down with high traffic.
Last month, i have diabled the bandwidth monitoring service for free web sites because it overloaded MySQL data base.
So i have installed System Integrity Monitor (SIM) on the server. Last few days i found there is too many down times, services like httpd, ftpd, sendmail and sshd won’t work. But server is responding well for PING, that is server is not down… but all required services are down… Every time i have to open a reboot ticket with data center to get the server back online… this will take near 30 mints to get the server rebooted by data center. Anyway server reboots are fast…
I thought server is getting down with high traffic, actually there was high traffic, many times, it was above 1 MB per second, if we allow this, server will exceed its monthly bandwidth limit of 1000 GB per month. High bandwidth is caused by the fact we don’t have the facility to limit bandwidth per web site.
So i disabled all mp3 files on the srever
# locate *.mp3
will give list of mp3 files on the server, i just copied every file locations and added “chmod 000 ” to the beginning of line with regular expression, that is replace “^” with “chmod 000 “.
Now bandwidth usage is under control, still at times, services become down, no access to server other than ping.
So i have through of perventing HOT LINKING. So i added .htaccess file to prevent hotlinking of files to all users.
Now users can’t hotlink images, exe, zip or rar files from other web sites, they need to link to a web page under their BizHat.com free home page.
These changes won’t made any improvement in server problems… server get down at times.
So i start looking into SIM.
I have read there is problem in using nice command with sshd .
So i reconfigured SIM
And disabled monitoring of service sshd.
Now SIM monitors services
8 – Warn
10 – Critical
Nice services when load level is Warn.
Reboot Server when load level is Critical.
After this change (removing sshd from SIM monitoring), server seems working fine.
SIM is System Integrity Monitor, that monitor your server at predefined time using cron job. If a service found down, it will restart the service. Also if the server load is above Warn level, it can nice the processes.
nice is a linux command used to set priority for processes running linux box.