Mailing-List: contact dev-help@httpd.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@httpd.apache.org
Received-SPF: neutral (asf.osuosl.org: local policy)
Message-ID: <445754DF.8060208@pearsoncmg.com>
Date: Tue, 02 May 2006 08:47:27 -0400
From: Chris Darroch <chrisd@pearsoncmg.com>
Organization: Pearson CTG/CMG
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060423
MIME-Version: 1.0
To: dev@httpd.apache.org
Subject: Re: [PATCH] #39275 MaxClients on startup [Was: Bug in 2.0.56-dev]
References: <20060408221021.GA10072@none.at>
	 <cc67648e0604100652q367cfdc6l4e62da81acd6868d@mail.gmail.com>
	 <443C16B1.1090706@pearsoncmg.com>
	 <cc67648e0604201533mc957795q7a571ba4b75781f1@mail.gmail.com>
	 <44567774.9070809@apache.org>
 <cc67648e0605020330q7fb6d0b7r7234f7dcb2245430@mail.gmail.com>
In-Reply-To: <cc67648e0605020330q7fb6d0b7r7234f7dcb2245430@mail.gmail.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Jeff Trawick wrote:

> On 5/1/06, Greg Ames <gregames@apache.org> wrote:
>
>> after more thought, there is a simpler patch that should do the job.  the key to both of
>> these is how threads in SERVER_DEAD state with a pid in the scoreboard are treated.  this
>> means that p_i_s_m forked on a previous timer pop but some thread never made it into
>> SERVER_STARTING state.
>>
>> the difference:  this patch just counts those potential threads as idle, and allows
>> MinSpareThreads worth of processes to be forked before putting on the brakes.  the
>> previous patch pauses the forking immediately when the strange situation is detected but
>> requires more code and a new variable.
> 
> new patch is fine with me; I think we've lost our other interested
> parties on this thread anyway ;)

   I'm still here!  I had to be away from the keyboard most of last
week, so have only returned to this thread (pun intended, alas) recently.
I also found myself fixing a variety of other things that turned up
in the vicinity of this issue; patches forthcoming on those subjects.

   This is indeed a very straightforward fix; I've been trying to
ponder its consequences overnight.  The questions I've got (no
answers yet, just thought I'd ping so you know I'm here) would be
(a) whether you want to allow for SERVER_GRACEFUL as well to be
counted as idle, and (b) whether there's any reason to want to
not proceed through the if (any_dead_threads && ...) logic that
follows in p_i_s_m().

   If you can bear with me for a day or two more, I should have
a collection of patches ready.  These tackle the issue by
tracking the start and listener threads in a nice new spot in
the scoreboard, and also clean up various issues and bugs relating
to fork(), ThreadLimit, ServerLimit, MaxClients, etc.  They also
tackle some issues raised in various XXX comments and clean up
some stale cruft in scoreboard.h.

Chris.

-- 
GPG Key ID: 366A375B
GPG Key Fingerprint: 485E 5041 17E1 E2BB C263  E4DE C8E3 FA36 366A 375B