- This thing is deprecated, please use my py-balancer, it does the samething, but much faster, and easier.
rbalancer is a simple HTTP load balancer using HTTP 302 redirect response with round-robin and weighted random support built on
rbalancer can perform health check on server in balancer list, when a server went down, rbalancer will automatic re-balance request to alive servers.
When dead one goes up, it will be added to cluster and serving request likes normal
If you have a farm servers to serve static file, and you want to load balancing between them, of course just once you have problem with LVS ldirector, (We used to have 3 LVS server to load balance our video streaming farm, when switching to rbalancer, we just need one 2 cores server with 200 MB ram usage) rbalancer will be your right choice.
Rbalancer server has original domain: img.org.domain.cdn.com, a img file on your site will have url img.org.domain.cdn.com/img/front_shadow.jpeg.
You have 2 servers behind rbalancer to serv that jpeg file which have following domain names:
- server 1 : img1.org.domain.cdn.com
- server 2 : img2.org.domain.cdn.com
Base on weigh of each server your defined in configuration file, rbalancer will balance request to server 1, or server 2 with a redirect response like this:
REQUEST (to rbalancer)
GET /img/front_shadow.jpeg HTTP/1.1 Host: img.org.domain.cdn.com
RESPONSE (from rbalancer)
HTTP/1.1 302 Found Location: img1.org.domain.cdn.com/img/front_shadow.jpeg
you can also view stats of rbalancer using URL: http://rbalancer_domain_name/stats . Stats of rbalancer shows how much request each server in cluster receive, how many requests/s it's serving, which servers was down.
rbalancer.conf is by default placed in
/etc if the package was intalled with root privileges. rbalancer itself can run as non root user which bind to high port. By default, rbalancer will run on port
[global] port = 9998 # Listening port. static_dir=/var/www/ [farms] list=stc,img ; config for ``img`` farm [img] list=srv1,srv2 domain=img.org.domain.cdn.com ;original domain [srv1] domain=http://img1.org.domain.cdn.com weight=20 enable=on [srv2] domain=http://img2.org.domain.cdn.com weight=10 enable=on ; config for ``stc`` farm [stc] list=srv3,srv4 domain=stc.org.domain.cdn.com [srv3] domain=http://img1.org.domain.cdn.com weight=10 enable=on [srv4] domain=http://img2.org.domain.cdn.com weight=10 enable=off
Server was configured with
enable=off will not receive request from rbalancer untill it is turned on.
Final note: you should put your favicon.ico in static folder configure in configuration file. Every http request made to your server will look for a favicon file.
In my test case, a 404 Not Found response costs 8ms when a 302 Redirect response just costs 0.03ms. It meant if you dont have favicon.ico file, it will take 8.03ms to serve a request. I will let you do the math.
See below for OS-specific preparations.
Install rbalancer with:
# python setup.py install
- Modify and rename /etc/rbalancer.conf.default to /etc/rbalancer.conf
- Start rbalancer
# /etc/init.d/rbalancer start