Hi,
I am maintaining a website which is running apache with php scripting language and php sessions.Now my webserver is not able to handle the requests.I am thinking of using a loadbalancing software.Can some list all the load balancing softwares available?
I did googling and found that reverse proxying,roundrobin dns,linux virtual server and ultramonkey are some of the opensource loadbalancing softwares.But i dont know which one to use.and the main problem to handle is whether it will be albe to handle php sessions (like all the requests from a user shud be directed to the same backend server).
There are many websites on internet which handles millions of users.Which load balancing software are they using?

With Regards,
CoolGuy

personally we do out load balancing with F5 LTM's at £40,000 a pop, but apache in itself makes a good load balancing front end for additinal backend apache boxes. check something like mod_backhand for a module for apache to do this.

can you elaborate a bit?

not really... just read the documentation for mod_backhand, and you'll see everythign you need to know. also remember that you have the option of load sharing by splitting functionality between servers, e.g. keep static content on one, images on another, and php on another. that's just a dns thing.