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From "Emmanuel Lecharny" <elecha...@gmail.com>
Subject Re: [PERFORMANCE] Disabling Nagle Algorithm improves performance
Date Mon, 19 Jun 2006 17:09:45 GMT
Whaouh !!!

Thanks a lot guys ! I gonna test that as soon as possible, and will
keep you informed of the results.

Thanks again !



On 6/19/06, Timothy Bennett <timothy.eugene.bennett@gmail.com> wrote:
> Alex Karasulu is on his way to the Caribbean for a well-deserved vacation...
>  Meanwhile, he asked me to post this message to the dev lists at directory
> and mina:
> ===========================
>
> The current problem where Directory is exhibiting an upper limit of 25
> requests/sec on an individual client connection is due to a 40 msec delay
> imposed by Nagle's algorithm (
> http://en.wikipedia.org/wiki/Nagle%27s_algorithm).
>
> The server's actual upper limit is currently measured at approximately 1,300
> to 1,500 requests/sec requires, which requires multiple connected clients to
> reach this limit.
>
> From the Wikipedia entry:
>
> "This algorithm interacts badly with TCP delayed acknowledgements, a feature
> introduced into TCP at roughly the same time in the early 1980s, but by a
> different group. With both algorithms enabled, applications which do two
> successive writes to a TCP connection, followed by a read, experience a
> constant delay of up to 500 milliseconds, the "ACK delay". For this reason,
> TCP implementations usually provide applications with an interface to
> disable the Nagle algorithm."
>
> MINA has a way to disable Nagle's algorithm by configuring the socket option
> to TCP_NODELAY.  Perhaps some others can pick up the discussion and carry
> on...
>
> --
> timothy


-- 
Cordialement,
Emmanuel L├ęcharny

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