Random Server Selection

zeke · Idler Joined: 04 Oct 2003 Posts: 325

Hey, I'm trying to figure out how to set up a random-server select, but I can't find anything on search engines that is of any use. Is anyone able to help me please?!?

Thank you!
zEkE

U · Eleet Joined: 18 Jun 2003 Posts: 521 Location: IRC

If you're talking about making a random server pool, it has to be done at the DNS server itself, and the DNS server must support 'round robin' so that it constantly rotates it.

If you don't host your own DNS, you should speak to your DNS provider about if the capability exists.

anifinder · none Joined: 14 Oct 2003 Posts: 28

In a DNS round-robin, what basically happens is that multiple A, or primary, records are added to your DNS zone file. What this does is cause irc.yourdomain.net to resolve to a different IP every time someone tries to connect, usually helping keep load balancing even. I don't know how the DNS server picks which record to answer with; it's probably buried in documentation somewhere.
I know there are a few sites out there that demonstrate how to do a round-robin. It's best to try searching Google for "DNS round robin records" or something similiar.
True DNS load balancing involves the DNS server polling every linked server and seeing which one is most capable of handling more users. This is very complex and beyond the scope of my knowledge. It's probably not worth it for more networks anyway; I don't know of any of the big nets that use it, offhand.
Overall, it's best just to go with a round robin.

U · Eleet Joined: 18 Jun 2003 Posts: 521 Location: IRC

You're correct, but your DNS also has to support moving the records, ie:

You have 3 servers in your dns:

server1
server2
server3

Now when the first request for the round robin is recieved, it will send back:

server1
server2
server3

If its standard DNS, it will keep doing that, so everyone will get dropped onto server 1 all the time first.

However, if the DNS supports round robin, it will rotate the records, so first request you will get:

server1
server2
server3

Second request you will get:

server3
server1
server2

in that order, and it will continue to cycle through. Thus it becomes a true random. Your DNS has to support this though, or it will always give the records as they are listed, in order, on your DNS config file. If the DNS host you use supports multiple A records and will rotate them, then you're set Smile

If not, it will work, but not as a true random-you'll always get the same servers in the same order, and mIRC will try the first IP it gets first, only falling to the second if that first connection fails.

You can do it the other way, but server1 will be always alot more full, and if it dies, then you drop alot more people Smile