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Date: Thu, 10 Feb 2005 08:24:17 -0500
To: dev@httpd.apache.org
Subject: Re: UNIX MPMs
References: <cufi2r$1to$1@sea.gmane.org>
From: "Paul A. Houle" <ph18@cornell.edu>
Organization: Cornell University Library
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On Thu, 10 Feb 2005 11:56:47 +0000, Nick Maynard  
<nick.maynard@alumni.doc.ic.ac.uk> wrote:


> UNIX MPMs that actually _work_ in Apache 2:
> 	worker
> 	prefork (old)
>

	Yeah,  but what if you want to run PHP or mod_perl?

	Sure,  PHP or mod_perl ~might~ work for you if you're lucky and you don't  
compile in the wrong third-party library,  but you'll be in a world of  
pain if you don't.

	It's very hard to bolt threading onto an existing system that links to  
legacy libraries.  Java managed to provide a thread-safe environment by  
having a painful API to link to C code,  "100% Pure Java" xenophobia --  
and it still took them 5 years to make a JVM which was reliable enough for  
government work.

	On Linux I've done some benchmarking and found that worker isn't any  
faster than prefork at serving static pages.  (Is it any different on  
other platforms,  such as Solaris?)  In principle you might save RAM by  
running prefork,  but in this day and age you can fit 16 GB in a 1U pretty  
easily and it's cheaper than hiring a programmer who doesn't know how to  
track down race conditions,  never mind one that does.