Bug 752491

Summary: Document optimal heartbeat timeouts
Product: Red Hat Enterprise MRG Reporter: Justin Ross <jross>
Component: Messaging_Programming_ReferenceAssignee: Cheryn Tan <chetan>
Status: CLOSED CURRENTRELEASE QA Contact: Frantisek Reznicek <freznice>
Severity: medium Docs Contact:
Priority: medium    
Version: 2.0CC: esammons, freznice, iboverma, lbrindle, pmoravec, rlandman
Target Milestone: 2.1.2   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 752510 (view as bug list) Environment:
Last Closed: 2012-05-02 05:31:42 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 706388, 752510    

Comment 1 Gordon Sim 2011-11-09 17:22:06 UTC
As Pavel notes in https://issues.apache.org/jira/browse/QPID-3264, you want to ensure that heartbeats are "at most 1/2 of TCP retransmission overall-time (that by default around 15 minutes on Linux and 12 seconds on Windows)". This prevents the situation where the client gives up on the connection and yet the broker assumes it is still established.

A footnote to that effect could be added to the documentation in the appropriate places (e.g. table 2.4 in Programming Guide and section 7.3 in User Guide).

Comment 2 Gordon Sim 2011-11-09 17:22:52 UTC
Should this not be assigned to a documentation component now?

Comment 3 Lana Brindley 2011-12-05 21:41:11 UTC
*** Bug 752510 has been marked as a duplicate of this bug. ***

Comment 4 Tim Hildred 2011-12-16 06:02:23 UTC
Committed revision 76539.

"Requests that heartbeats be sent every N seconds. If two successive heartbeats are missed the connection is considered to be lost. Heartbeats should be defined to, at most, 1/2 of TCP retransmission overall-time. By default, TCP retransmission time is around 15 minutes on Linux and 12 seconds on Windows."

Comment 5 Tim Hildred 2011-12-16 07:02:47 UTC
Red_Hat_Enterprise_MRG-Programming_in_Apache_Qpid-2-web-en-US-2-1.el6eng

Comment 6 Frantisek Reznicek 2012-02-01 09:18:43 UTC
Neither of following documents contain cited paragraph
  Red_Hat_Enterprise_MRG-Messaging_User_Guide-2-web-en-US-2-15.el6eng
  Red_Hat_Enterprise_MRG-Programming_in_Apache_Qpid-2-web-en-US-2-5.el6eng
doc.stage:
  Red Hat Enterprise MRG 2 - Programming in Apache Qpid
  Red Hat Enterprise MRG 2 - Messaging_User_Guide


Unfortunately Red_Hat_Enterprise_MRG-Programming_in_Apache_Qpid-2-web-en-US-2-1.el6eng is deleted already, but it seems the above mentioned commit was omitted or just not merged to package. Package changes-log proves that, no comment about heartbeat doc update neither in 
  Red_Hat_Enterprise_MRG-Programming_in_Apache_Qpid-2-web-en-US-2-5.el6eng
nor in
  Red_Hat_Enterprise_MRG-Programming_in_Apache_Qpid-2-web-en-US-2-2.el6eng

Tim,
could you possibly doublecheck whether I look at correct packages, please?


-> ASSIGNED with NEEDINFO

Comment 9 Frantisek Reznicek 2012-02-24 10:28:41 UTC
As far as I checked neither documentation stage nor package in Brew contains patch which would allow me to put this defect to VERI.

Hi Cheryn,
could you possibly apply above patch and let me know where I can check it, please? (either rpm or doc. stage)

Comment 11 Frantisek Reznicek 2012-02-28 08:38:37 UTC
Above cited paragraph (comment 4) was added to Programming_in_Apache_Qpid docs.

-> VERIFIED

Comment 12 Cheryn Tan 2012-05-02 05:31:42 UTC
Documents have been published on http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/index.html as part of the MRG-M 2.1.2 update.