jesus at omniti
Oct 10, 2003, 5:49 AM
Post #2 of 3
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On Friday, Oct 10, 2003, at 08:11 US/Eastern, Rob Clews wrote:
> I wish to use a load balancer which then forwards to other nodes in a
> network. Previously I've been using other software on the load
> balancer,
> but when the requests hit the load balancer which are then forwarded on
> they stay on the load balancer. The result is that the load balancer
> gets filled up with TCP_TIME_WAITs and after x amount of requests will
> not handle any more.
>
> Is there a way of using mod_backhand so that the clients do not leave a
> connection on the load balancer?
> <snip>
> Obviously the load balancer is the single point of failure currently,
> that will change later. We will be receiving a large amount of requests
> and the focus is on speed other than availability.
This has little to do with mod_backhand. It is a TCP/IP stack tuning
issue. You should be able to reduce the amount of time TCP/IP
connections are kept in TIME_WAIT. This could be due to improperly
shutting down the TCP/IP connection from the load balancer.
mod_bakchand doesn't do anything to exacerbate the problem, but it is
still a kernel tuning issue (on Linux, Solaris and FreeBSD).
On Linux and FreeBSD you can use sysctl to modify the appropriate tcp
timeouts in the kernel's TCP/IP stack.
On Solaris, you can use ndd.
// Theo Schlossnagle
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