Manage Apache Download Speed And Traffic Limits With mod_cband - Page 2

3 Apache Configuration

You can find all configuration directives on mod_cband's documentation page; I will describe the most important ones here.

In this chapter I assume we have a web site on the IP address with the document root /var/www and the following vhost configuration:

ServerAdmin [email protected]
DocumentRoot /var/www

Please note: It is important that your vhost includes the ServerName directive (e.g. ServerName and that your mod_cband directives come after that directive, otherwise you will get a warning like this when you restart Apache:

Starting httpd: [Mon May 29 18:05:33 2006] [warn] Invalid command 'CBandSpeed', undefined virtualhost name

You can use the following units in the mod_cband directives:

Transfer speeds:

  • kbps: 1024 bits per second
  • Mbps: 1024*1024 bits per second
  • Gbps: 1024*1024*1024 bits per second
  • The default is kbps.

Transfer quotas:

  • K: 1000 bytes
  • M: 1000*1000 bytes
  • G: 1000*1000*1000 bytes
  • Ki: 1024 bytes
  • Mi: 1024*1024 bytes
  • Gi: 1024*1024*1024 bytes
  • The default is K.

Time periods:

  • S: seconds
  • M: minutes
  • H: hours
  • D: days
  • W: weeks
  • The default is S.

First we add the following two directives to the global Apache configuration (not to the vhost from above!). They are needed to improve mod_cband's performance.


vi /etc/apache2/apache2.conf


vi /etc/httpd/conf/httpd.conf
CBandScoreFlushPeriod 1
CBandRandomPulse On

Now we create the scoreboard directory for our vhost, /var/www/scoreboard. The directory must be writeable by the Apache user:


mkdir /var/www/scoreboard
chown www-data:www-data /var/www/scoreboard/


mkdir /var/www/scoreboard
chown apache:apache /var/www/scoreboard/

3.1 Configure Download Speed

Now let's say we want to limit the download speed. We can do it like this:

ServerAdmin [email protected]
DocumentRoot /var/www
CBandSpeed 1024 10 30
CBandRemoteSpeed 20kb/s 3 3

The CBandSpeed directive limits the overall Apache performance for the vhost to a speed of 1024kbps, max. 10 requests per second and max. 30 open connections.

The CBandRemoteSpeed is like the CBandSpeed directive, but it sets limits for any individual user (as compared to the overall settings made by CBandSpeed).

After your changes, you must restart Apache:


/etc/init.d/apache2 restart


/etc/init.d/httpd restart
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By: Wedesign Marbella


 What would be the configuration to allow a site with only 80Gb per month?

Thanks in advance,

By: Lord Readman

In response to Wedesign Marbella

#the scorebord of the virtual host
CBandScoreboard /var/www/scoreboard/site.scoreboard
#this would set the limit to 80GB
CBandLimit 80G
#this is the period of 30days (set to 31 if you wish)
CBandPeriod 30D
#if 80G is exceeded give everyone a 509 Bandwidth Exceeded Error.
CBandDefaultExceededCode 509

 Of course you can tailor your config to your custom requirements.

By: Wedesign Marbella

Many thanks

By: Anonymous

Hello, and thank you for writing this text.

How can I limit ips in downloads. ex: every ip can only download one time.

By: Anonymous

I want use mod_cband with mod_proxy(apache2 with tomcat cluster). Any one has idea?