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How many connections can Unreal hold?

Posted: Sun Jun 05, 2005 6:28 am
by Castalia
I really think ircd is faster than any other online chat system, but how many connections can Unreal hold? 10,000 ? 100,000 ? or only 1,000?
If i want to setup an online chat system may be have over 100,000 connections, is Unreal the best selection?

Posted: Sun Jun 05, 2005 8:59 am
by Dukat
It's possible to have that many clients, of course you have to use more than one server and link them together.

I really hope you aren't asking if Unreal is the best selection for your botnet...

Posted: Sun Jun 05, 2005 10:14 am
by Suchiara
mhm.. yeah, such stats would be interesting :)
I saw in some ircd's documentation writtnen: max 1024 servers linked and max 2 million users per server (don't remember what it was) :) It would be interesting to know this about Unreal IRCd 8)

Posted: Sun Jun 05, 2005 10:39 am
by w00t
I'm sorry, but 2 million per server simply won't happen ;).
As for servers, I doubt you'd get a (useful) network bigger than say, 60 to 70 servers. Look at the problems the current ones have with splits and lag, and you'll understand why. Theoretically though, from memory the maximum number of servers on an Unreal network is limited to the number of numerics used, so 1-255 - ie 255 :).

The most users you'll EVER get (any ircd) is around 80,000 from memory - and only that with a heavily tweaked kernel/OS.

As for actual amounts of clients/performance, it varies. I've been stress-testing some services I'm working on, and with 270 clients hitting it with everything from MOTD/INFO, privmsg, nickchanges etc, Unreal has been using roughly 50% CPU on a p4 3ghz machine. That said, they are hitting it very heavily. (to give you some idea, the load average ended up over 250). Most of the CPU usage can probably be attributed to spamfilter.

A production IRCd I run (with roughly 40 clients):
ircd 2956 0.0 0.5 3592 2720 ? S May18 0:43 /home/ircd/ircd
Unreal has been up for 17 days, 17:30:03.

Posted: Sun Jun 05, 2005 2:38 pm
by JessieJames
running FreeBSD 5.3 os say 3348 connection allowed and have ircd.conf set at 3300 but with less the 1000 connection iam getting this = *** Notice -- All connections in use. is this os problem?

Posted: Sun Jun 05, 2005 4:22 pm
by Syzop
The message is generated if the # of connections exceeds MAXCONNECTIONS ('grep MAXCON include/setup.h').

If you think unreal is wrong, for example if your MAXCONNECTIONS is set at 3000 and it already has this problem at 1000.. then I suggest doing an 'lsof -n -p <pidofunreal> >lsof.txt' and check lsof.txt to see if it is leaking any fds. And then submit this information to bugs.unrealircd.org.

--

Just for reference, I've done clonetests with 10K clients on both Linux and Windows (for some reason I always have a fight with freebsd, but just ignore that ;p), It isn't exactly going smoothly on lowspec machines (say, a p450 w/384M) -- it can especially require a lot of memory for (socket) buffers etc. And indeed, CPU becomes quite an issue, especially if you use spamfilter. Therefore it's usually better to spread it over several servers.
Speaking network-wise, Unreal has quite some insane limits ;p... max 255 servers, not really a global client limit (well, 2 billion users), channels are limited to 65535 users atm though ;p.

Posted: Sun Jun 05, 2005 7:03 pm
by Suchiara
cool 8) powerful thing :twisted:

Posted: Mon Jun 06, 2005 5:57 am
by w00t
Syzop, how in the HECK can I get up to 10k when I'm having trouble getting past 300 :P Can I ask you what your configuration/setup is?

Posted: Tue Jun 07, 2005 8:44 am
by Castalia
max 1024 servers linked and max 2 million users PER server :o
woooo.....then there's 2*1024=2048 million users totall?!!

in fact, i really havn't seen a irc server that has over 10 thousand users online :P But this is a problem worth to discus,isn't it? :wink: