Friday, 26 Apr, 2013 apache Intro. The Apache Bandwidth module allows you to limit the allocated bandwidth on a per-VirtualHost basis, which is very useful on hosted scenarios (many sites on a single IP) or if you're simply hosting your own site at home. First check if you have it installed already: apachectl -M |grep mod_bw Install mod_bw. Then, on CentOS/Ubuntu, install it by doing: yum install mod_bw; apachectl -k graceful sudo apt-get install libapache2-mod-bw; sudo a2enmod bw Here's an example I successfully used to limit the available bandwidth on a named virtual host site: <VirtualHost server-ip:80> BandwidthModule On ForceBandWidthModule On Bandwidth all 20480 MinBandwidth all 500 LargeFileLimit * 1024 500 ServerName www.site.it ServerAlias site.com.au [...] </VirtualHost> mod_bw vhost config. Bandwidth all 20480 allocated 20Kb/s (20480/1024) to every user (it was a very fascist limit, but hey, I was in Italy!). Instead of "all", you may specify IP Addresses or subnets with an /XX notation and you can also declare multiple Bandwidth-entries (ie. BW localhost XX; BW 192.168.0.0/24 YY). ForceBandWidthModule On forces the module to apply to every request (the man says mod_bw by default doesn't apply to every request), but I suppose this may increase the server load - just speculating here, so bear with me. MinBandwidth all 500 allocated a minimum bandwidth of 500 bytes (0.48k!) to every user. Both the previous commands, when applied, meant the 1st user would have a total of 20Kb/s, from the 2nd client on, the total Bandwidth would've been splitted (10k each), with a MinBandwidth for every user of 0.48k. LargeFileLimit * 1024 500 is a limit on a per-file basis. Here I did limit ALL the files with an asterisk, but I coulda specified different specific extensions (i.e.: by specifying multiple LargeFileLimit-entries - ".avi", ".tbz2", ".mp3", etc.). 1024 specifies the single file size limit in Kbytes, the 500(!) specifies the maximum bandwidth available to filetypes in bytes/s. A good alternative way to use mod_bw is to declare the "MinBandwidth -1" parameter, which means each user will have a top Bandwidth specified by the "Bandwidth" directive (ie.: everybody will have the same top bandwidth) like so: Bandwidth all 20480 MinBandwidth all -1 MaxConnection all 8 In this example all woulda had a top limit of 20Kb/s, which sounds decisively less fascist! I've also added a statement to limit the maximum number of connections. Please note this can be used only if you also declared a "Bandwidth" statement AND it must also be applied only to the same Bandwidth "XXX"-users (i.e.: don't use MaxConnection if you don't use Bandwidth). BTW, this should limit the maximum number of connections per IP to 8. Some considerations. That said, mod_bw is a beautiful toy that allows you to set your bandwidth limits on a per customer-basis, and that's the best way (absolutely IMHO) to use it. You need to first identify your "resource-hog" sites, study how much bandwidth per-user they need and, depending on how much bandwidth you have available, verify how it works under different scenarios, but this is also risky since how a sites develops is (generally) not easy to predict (and good values for today usage are not always good values for tomorrow scenarios). That could represent a good intro, for more info, look at the man page: http://bwmod.sourceforge.net/files/mod_bw-0.7.txt 5/5 - (2 votes) Andrea MatesiSenior Professional Network and Computer Systems Engineer during work hours and father when home. Andrea strives to deliver outstanding customer service and heaps of love towards his family. In this Ad-sponsored space, Andrea shares his quest for "ultimate" IT knowledge, meticulously brought to you in an easy to read format. Share this:LinkedIn Related