[jdev] Re: [jadmin] Re: One million concurrent user

[Tijl Houtbeckers]

On Fri, 28 Jan 2005 10:19:09 -0500, dlb <civintel at comcast.net> wrote:

> From: jdev-bounces at jabber.org [mailto:jdev-bounces at jabber.org] On Behalf  
> Of
> Richard Dobson
>
>> Right now we have moved all jabber services to its own box ...
>>> You will need an architechture that distributes components of the  
>>> server
> over multiple physical servers.
>
> Before you commit to a server, you might want to get an idea of your  
> options
> for networking and managing this installation - this may impact your  
> server
> choice. You're not going to be able to buy a million CC installation
> off-the-shelf - ie. your not buying a million cap installation, you're
> building one.  You need to speak to someone who's familiar with this  
> scale
> of implementation. And it's going to cost a lot of money !

I quite agree with this post. Implementing a million concurrent users with  
current opensoure software shouldn't be too hard. However, as you spread  
the load over different machines the number of potential single point of  
failures increases.

What kind of service will you be running? How important is uptime for you?  
It's easy to say: "I want a million concurrent users and 99,99% uptime".  
What's less easy is getting the beancounters to cough up the money you  
need for that. Certainly the "big ones" in the consumer IM world don't  
have that kind of numbers for uptime.. MSN seems to be down or unusable a  
half a day long at least once a month here. When I used ICQ in the "old  
days" it certainly wasn't any better.

Opensource will get you quite far when it comes to the number of  
concurrent users on commodity hardware. WPJabber, a modification of the  
tried and trusted Jabber 1.4 is already used on a daily basis for over  
>100.000s. It however has no or little special techniques for redundancy  
etc, at least not as far as I know. There is the alternative of EJabberd  
though. Not only is it very feature complete, it's written in Erlang. If  
you don't know what that is do a Google search on that and you see why it  
might be a good choice for you.

But indeed, the software will only get you that far. For the rest it  
depends on you. If you pay big money to folks who have the experience and  
who've done it before it might get you there quicker.