Bug 683503

Summary: Include description of producer flow control in Messaging documentation.
Product: Red Hat Enterprise MRG Reporter: Ken Giusti <kgiusti>
Component: Messaging_Programming_ReferenceAssignee: Alison Young <alyoung>
Status: CLOSED CURRENTRELEASE QA Contact: ecs-bugs
Severity: medium Docs Contact:
Priority: medium    
Version: betaCC: jneedle, ppecka, sburgess, tross
Target Milestone: 2.0   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-06-24 02:52:55 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: 660526    
Bug Blocks: 660291, 660531, 703984    

Description Ken Giusti 2011-03-09 15:30:27 UTC
Description of problem:

Producer flow control is a new feature available in the 0.10 release of the C++ broker. See https://bugzilla.redhat.com/show_bug.cgi?id=660291

The upstream documentation has been updated to describe this new feature:

https://issues.apache.org/jira/browse/QPID-3128

Red Hat's documentation should be updated to match.

Version-Release number of selected component (if applicable):


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Comment 2 ppecka 2011-04-07 08:51:02 UTC
it might be also valuable to point out how default values are determined, if they are not set explicitly on queue creation.

eg
i'll set 
flow-stop-size=200 ( so stop-size < default-stop-size )
what value is flow-resume-size?

if i set following values, at the end resume-size will not be the value i've set 
flow-stop-size=200
flow-resume-size=0

flow-stop-size=0
flow-resume-size=200

Comment 3 Ken Giusti 2011-05-11 18:22:38 UTC
See the upstream documentation for details about this feature:

http://qpid.apache.org/books/0.10/AMQP-Messaging-Broker-CPP-Book/html/ch01s09.html

Comment 4 Alison Young 2011-05-12 01:07:34 UTC
Thanks Ken, that's a better source than what I'd been able to find upstream. Working on this today (Thursday May 12).

Comment 6 Ken Giusti 2011-05-13 14:18:04 UTC
This looks great!

I did find one problem - appears to originate with the original upstream text - see 3 corrections below in []'s:



Queue Threshold Example
Consider a queue with a maximum limit of 1000 on the total number of messages that may be enqueued to that queue. If a user configures flow-stop-threshold [SHOULD BE "flow_stop_count"] with the value 900, and flow_resume_threshold [SHOULD BE "flow_resume_count"] with the value 500. With these thresholds the following queue activity occurs:

    *
      When the total number of enqueued messages is greater than [SHOULD BE "less than"] or equal to 900, the queue's flow control state is OFF.
    *
      When the total number of enqueued messages is greater than 900, the queue's flow control state transitions to ON.
    *
      When the queue's flow control state is "ON", it remains "ON" until the total number of enqueued messages is less than 500. At that point, the queue's flow control state transitions to "OFF".

Comment 7 Alison Young 2011-05-15 07:05:05 UTC
Thanks Ken, your producer flow control expertise is most appreciated. Will get those fixes in this week.

Comment 11 ppecka 2011-05-24 10:11:23 UTC
--> VERIFIED