20,000 network connections per tcp server + max nodes

Joel Reymont <>
Mon Aug 29 01:03:26 CEST 2005

On Aug 28, 2005, at 9:14 PM, Daniel Schutte wrote:

> connected nodes
>  The maximum number of simultaneously connected nodes is limited by  
> either the
> maximum number of simultaneously known remote nodes, the maximum  
> number of
> (Erlang) ports available, or the maximum number of sockets available.

That's music to my ears!

>  The maximum number of simultaneously open Erlang ports is by  
> default 1024.
> This limit can be raised up to 262144 at startup (see environment  
> variable
> ERL_MAX_PORTS in erlang(3)).

I wonder how Erlang can manage to monitor 262,144 open file  
descriptors on one node. Any ideas?

> The question I would like to ask however is why would you like to  
> have 500k
> simulatenous players in a "single cluster" :)

A cluster could be a rack of 1U boxes, about 40 or 50 would fit.

Someone just asked the question of how I would support 500k players  
at the same time. I figured 10k players per node, one node per box,  
would require 50 boxes. I got my math wrong which got me worried :-).

> the max poker table size = 10?

I'm not sure what you mean by that.

> My reasoning being that have the connections as seperate tcp/ip  
> connections
> (to various machines that handle X tcp connections per machine),   
> and then
> just allocate each "player" to a table - that can work in a "casino  
> cluster"
> of about 5000 tables per server (if that is how you want to do it).

That's how I do it, I believe. I already have the server developed.

> Benchmarking on physical memory on the box and processor speed will  
> determine
> the required hardware or rather the number of supported clients per  
> box.



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