rbalancer

• 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 tornado. 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

Example usage

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.

Usage

rbalancer.conf

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 9998.

[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.

Installation

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

License

GPL