Bug 1157769

Summary:	JWS: VirtualHosts share pointer to mod_proxy configuration, results in: CreateBalancers behave the same with option 0 or 2
Product:	[Retired] JBoss Web Server 3	Reporter:	Michal Karm Babacek <mbabacek>
Component:	mod_cluster	Assignee:	Jean-frederic Clere <jclere>
Status:	CLOSED DEFERRED	QA Contact:	Michal Karm Babacek <mbabacek>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	3.0.0	CC:	jclere, jdoyle, lcosti, mbabacek, pslavice, rmarwaha, rsvoboda, smumford
Target Milestone:	DR02
Target Release:	3.0.0
Hardware:	All
OS:	All
Whiteboard:
Fixed In Version:		Doc Type:	Known Issue
Doc Text:	The directive `CreateBalancers` with the option `0` or `2` creates the balancers on all Apache HTTP Server virtual hosts. When using option `2`, it is expected that the balancers should be created on the main server only, and not on the virtual hosts. The cause of this issue is under investigation, and is expected to be resolved in a future release.	Story Points:	---
Clone Of:	1157766	Environment:
Last Closed:	2015-08-20 06:37:08 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1157766
Bug Blocks:

Description Michal Karm Babacek 2014-10-27 16:31:37 UTC

+++ This bug was initially created as a clone of Bug #1157766 +++

Please, read this description [1] and follow https://issues.jboss.org/browse/MODCLUSTER-430
for details.

This bug is deeply tricky and it has been around for quite some time. It's actually linked to Apache HTTP Server mod_proxy code integration.
We may even speculate whether it might be the root cause of some other mod_proxy integration issues, such as MODCLUSTER-391.


[1] https://github.com/modcluster/mod_cluster/pull/119#issue-45463288

Comment 1 Jean-frederic Clere 2015-01-20 16:40:01 UTC

Actually JWS3 upgrade to httpd-2.4.x so the BZ should be gone there.

Comment 2 Michal Karm Babacek 2015-01-26 17:06:39 UTC

The issue is httpd 2.4/2.2 agnostic, so it will not be gone in JWS3.

I shall revisit the approach outlined in https://github.com/modcluster/mod_cluster/pull/119#issuecomment-58634743 in the beginning of February; I agree that the current PR is too much "mod_proxy dependent".

Comment 4 Jean-frederic Clere 2015-02-26 16:41:01 UTC

Make it a known issue... It seems there isn't a good fix :-(
http://httpd.apache.org/docs/current/mod/mod_proxy.html#balancerinherit might be used instead.

Comment 5 Jean-frederic Clere 2015-02-26 16:43:02 UTC

Michal could test if BalancerInherit does something with mod_cluster?

Comment 7 Michal Karm Babacek 2015-03-17 10:27:41 UTC

Ad comment 5: I remember I tried that back in the day (BalancerInherit). It didn't affect the error, because servers share the same pointer, i.e. the configuration is not merely copied through.

IMHO, There is a good solution: One needs to call the mod_proxy config function in mod_cluster config phase (instead the current implementation-fragile mimicking that function) See my question regarding the improvement in: https://github.com/modcluster/mod_cluster/pull/119#issuecomment-58634743

Comment 8 Michal Karm Babacek 2015-04-23 07:14:21 UTC

Resetting devel_ack flag, because it had been based on comment 3 that was obsoleted by comment 7.

Comment 9 Michal Karm Babacek 2015-08-20 06:37:08 UTC

Moved: https://issues.jboss.org/browse/JWS-87