Re: many outgoing tcp sockets are slower than a few

[bert hubert <ahu@xxxxxxx>]

On Mon, Feb 21, 2005 at 06:17:16PM +0100, Christian Schmid wrote:

> Because thats the first I excluded. I changed the program by replacing 
> sendfile with a caching-routine plus syswrite. And it was really 
> interesting that the syswrite was the one which needs most of the 
> real-time, not the caching-routine. syswrite blocked 100 ms per socket.

Do you poll/select for socket readiness before doing write() with EAGAIN?
(shouldn't matter all that much, but could narrow down debugging)

100ms is a bit of an odd number - how big is your write (in bytes)?

Do you have 3500 threads or processes, or one big one?

What does 'id' say in vmstat 1 typically, both below and above 3500 sockets?

Thanks.

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