X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:message-id:content-type
	:content-transfer-encoding:mime-version; q=dns; s=default; b=Hi7
	0TQ9nC0XbnIoZ+ekLv2gYCjdY/0W2/4amOVqercjwzEgMAQDuy/0wSm8k66QCTti
	gmxhEa9gdz32R2EsUhGZWsbV4KLNxgWos3jxtTeATMjqF6YRwFF+jIP0lGB6JtM0
	EaknoPLVmNxVIkBDXXxpUpXSSCy1o0HKGqO97oJ0=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:message-id:content-type
	:content-transfer-encoding:mime-version; s=default; bh=ZDh4F5l5r
	KdcrM6AbglEVvVOeAg=; b=YCgy3IsqTMjLFJTld9S2qOO/K41cbqsmo4E6ztEvP
	VM5sulXLJUjg2ltVjyMuBmbb54iKEuosGJ6W0xVSgmbRN3LKGo1zMu2uLHiudGSK
	s1SopmC/0pPmVUbQnSL7JCO+01TiPiwK77kdl9szXVjViKKhr4iaohpjpmjrZBfg
	Is=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-0.4 required=5.0 tests=BAYES_50,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 spammy=H*r:sk:TLS_RSA, accidental, balancing, HX-CFilter-Loop:Reflected
X-HELO:	amcrelay1.faa.gov
X-IronPort-Anti-Spam-Filtered:	true
X-IronPort-Anti-Spam-Result:	A2GKAQBFrKNXfY8jOqJdgxh2DYEDpwGLKYI8hDiBfYYdAoFIOBQBAQEBAQEBAw8BARYrL4RfAQQBOlEBCA0VFEImAQQbiCEIAQSfA59tDAEkineEQAJKgmCCLwWZNAeMAoR7h2mFVUiLaYN3HoJIHIFMhxp/AQEB
From:	<Dominic DOT R DOT Jones AT faa DOT gov>
To:	<cygwin AT cygwin DOT com>
Subject:	Re: httpd-2.4.23 notice "No slotmem from mod_heartmonitor"
Date:	Thu, 4 Aug 2016 21:02:14 +0000
Message-ID:	<9820E0FA51BA9E488013F2BC442C0A6D640D2A@006FCH1MPN2-072.006f.mgd2.msft.net>
MIME-Version:	1.0
X-CFilter-Loop:	Reflected
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id u74L2Yko026817

>> Activating mod_slotmem_shm (as a shared module) resolved this issue and
>> allowed httpd to start.  However, httpd now produces the following notice
>> on (successful) startup:
>> 
>>     [Mon Jul 25 09:27:40.718810 2016] [lbmethod_heartbeat:notice] [pid2345] 
>> AH02282: No slotmem from mod_heartmonitor
>> 
>> I'm wondering if there changes to the static modules included in the new
>> version's package.  The changelog for httpd itself didn't suggest any changes
>> between these two versions that would cause configuration differences.

I was able to eliminate the notice by adding --disable-lbmethod-heartbeat to CYGCONF_ARGS in the .cygport file.  Looking up the notice in the package's source code, it appears that the lbmethod_heartbeat module is attempting to use shared memory (slotmem) created by the heartmonitor module (using the slotmem_shm module) and failing, thus producing the notice.  While this notice appears to be nonfatal, I wonder if it would pose a problem if actually using proxy load balancing; the lbmethod_heartbeat module provides one of four algorithms available for proxy load balancing and may not work properly.

Interestingly, this issue does not appear under the previous version, 2.4.20, of the httpd package.  Comparing the .cygport files for 2.4.20 and 2.4.23 shows that the only difference is the value of VERSION.  Also, 2.4.23 now requires the slotmem_shm module (either static or shared) whereas 2.4.20 did not.  It appears that there may have been an upstream change resulting in this issue.  However, reviewing the changelog for httpd itself (versions 2.4.21 through 2.4.23) didn't reveal any apparently relevant changes.

Experimenting with my previous thought that other modules may need to be compiled as static, instead of shared, modules didn't resolve the issue.

As noted above, disabling the lbmethod_heartbeat module removes the notice.  This action doesn't address the root problem for someone who wants to use this proxy load balancing algorithm, but it should prevent accidental use of an algorithm that may be functioning improperly.


-----

Dominic R. Jones, Ph.D.

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -