[Nottingham] Load balance...Linux solution.

[Graeme Fowler]

On Mon, 2004-03-15 at 20:34, Colin Saxton wrote:
> Interesting problem here that is itching for a Linux solution.

http://www.linuxvirtualserver.org/

There's many ways to skin that specific cat, most being based on LVS -
which provides the IPVS kernel framework.

HTTP is extremely easy, seeing as it usually requires basic round-robin
or least-connections algorithms. RDP should also be fairly easy, but
will require clever use of persistence since many users leave sessions
logged in but disconnected and will probably expect to find themselves
connecting to the same machine when they come back.

> have started to look at RedHat's piranha services

...the working end of which is based on the IPVS framework anyway -
Piranha is the python-based (IIRC) GUI to drive it.

I'd also recommend that you have a look at the following sites:

http://www.keepalived.org/ (failover, VRRP, IPVS daemon)
http://www.linux-ha.org/ (failover & general HA utils)
http://www.ultramonkey.org/ (complete HA & LB package)

Of course, for web serving you could also look at Apache's mod_proxy
module, or Squid (or any of the other widely available web cache apps).
By using them in "reverse" you can achieve a certain amount of LB
functionality, albeit at the loss of the failover & HA idea.

If you need more help with IPVS, feel free to ask. One or two of the
routing concepts can be tricky, for starters; the paradigms you may be
used to are frequently turned upside-down...

Graeme
-- 
Graeme Fowler <graeme at graemef.net>