Bug 248157

Summary:	qdisk integration with watchdog daemon
Product:	Red Hat Enterprise Linux 5	Reporter:	Lon Hohberger <lhh>
Component:	cman	Assignee:	Marek Grac <mgrac>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	5.0	CC:	cluster-maint, krzeszut
Target Milestone:	---	Keywords:	Reopened
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-09-04 11:15:23 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Lon Hohberger 2007-07-13 14:56:25 UTC

Description of problem:

Qdisk does monitoring of external resources for a node in a cluster.  Of course,
so does the watchdog daemon.

The request is to allow qdisk to use the watchdog's internal status as the sole
heuristic for fitness for participation in the cluster - thereby reducing the
load as well as duplicate effort on the system.

Qdisk currently uses blind heuristics based on external means, which gives it
great flexibility.  The watchdog daemon uses internally-coded ones, which gives
it better operational capability in high-memory pressure or high-load situations.

Comment 1 Lon Hohberger 2007-07-24 14:07:13 UTC

This will require changes to the watchdog daemon.

Generally, what I'm after here is a way for other apps to read from the watchdog
daemon's internal state.

Comment 2 Lon Hohberger 2007-07-24 14:09:09 UTC

This functionality may already exist, however, the specifics are that it should
be a low-overhead method - like shared memory or something - so that we can be
as memory-neutral as possible (compared to a socket which allocates buffers, for
example).

Comment 3 Kiersten (Kerri) Anderson 2007-11-05 23:26:18 UTC

Moving this to 5.3 unless Marek has something ready.

Comment 6 Lon Hohberger 2008-09-04 11:15:23 UTC

This could be stabilizing to the watchdog daemon.

Comment 7 Lon Hohberger 2008-09-04 11:15:37 UTC

Er, destabilizing...