Re: hubs and load

[Kurt Roeckx <Q@xxxxxxx>]

On Wed, Mar 28, 2001 at 04:08:22PM -0500, John Saylor wrote:
> 
> > A single server can easely support a few thousand clients.
> 
> Maybe I'm misreading, or just dense, but in config.h MAXCONNECTIONS is
> 50. I bumped it up to 500, but it seemed like a dangerous move to me.
> Since it's not a production system [yet], if it falls from load it's no
> big deal; but I'd like to avoid it. Your comment leads me to believe
> MAXCONNECTIONS could be 5000.

ircd wouldn't have a problem with it.  There are servers who have
more clients than that.

> > It really depends on your hardware and OS.
> 
> 686 CPU, 256 MB RAM, Linux 2.4.1

The problem is going to be the OS.  Most big client servers run
something else then Linux.
You need to tune it if you want to handle that amount of clients.
It will run out of kernel buffer space.

Depending on the OS, you have to do it differently.  I have no
idea how you have to do it with Linux, but I know someone is
running it with more then 5K clients.

> I think the boxes will have at least 2 network interfaces, one for
> clients and a second one for the servers to talk to each other on [on
> their own ethernet].

I don't really see the need for this.  You can give 1 interface
more as one ip address if that's what you want.

> And while I have some of your attention, if load requires, I'm thinking
> of running multiple ircds on one machine [connected via UNIX sockets],
> one being a hub and the others being leafs. I have heard this is common.
> Is it needed for the load I'm anticipating?

It doesn't make much sense to run it on the same box.  If 1 ircd
can't handle it, it's very unlikely 2 will be able to handle it.

> At what point should another server be added- 500 clients, 1000, 2000,
> ...?

>From the moment you start to have a problem, I guess.


Kurt