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From Greg Ames <>
Subject Re: are we ready to roll?
Date Fri, 10 Aug 2001 05:17:38 GMT

> Known issues with 2.0.23:
> 1) Win9x, WinME, and Netware do not yet work.
> 2) Unix: The threaded MPM might take longer than expected to perform
>    a graceful restart if an insufficient number of incoming requests
>    are being received at the time of the restart.  

Sorry I missed it when you first wrote this, but the sentence above
isn't stricly true, and I believe it may be causing some folks to be
overly alarmed about threaded. 

Graceful restarts happen just as quickly in threaded as with prefork, as
far as parsing the config file, serving new http requests with the new
config, and finishing old requests are concerned.  The one and only
thing that may take longer under low load conditions is cleaning up idle
threads and their processes from the old generation.  I don't consider
that much of a concern, especially since any new requests help resolve
the situation.

As you know from personal experience, you can do several graceful
restarts per second with threaded in 2.0.23, without problems.    

>                                                    This is due to the
>    accept model for connections used by the threaded MPM and the fact that
>    workers cannot be awakened to receive the shutdown signal until they
>    receive an incoming connection.  A new MPM (temporarily called "worker")
>    is being developed to correct this problem using a different accept
>    model, though it is not ready yet.  For now, the prefork MPM is
>    considered the most stable (and is therefore currently the default),
>    though threaded has made quite a bit of progress since 2.0.22.  We are
>    very interested in real-world performance comparisons between
>    prefork and threaded, particularly on heavily-loaded servers.
>    Any feedback along those lines would be greatly appreciated.

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