Bug 441700

Summary:	Add a 'ring' queue
Product:	Red Hat Enterprise MRG	Reporter:	Gordon Sim <gsim>
Component:	qpid-cpp	Assignee:	Gordon Sim <gsim>
Status:	CLOSED ERRATA	QA Contact:	Kim van der Riet <kim.vdriet>
Severity:	low	Docs Contact:
Priority:	high
Version:	1.0	CC:	davids
Target Milestone:	1.1
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-02-04 15:36:07 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:
Bug Depends On:
Bug Blocks:	471300

Description Gordon Sim 2008-04-09 15:31:48 UTC

The core feature would be to have a fixed size queue (fixed in the number of
unacked messages). Once this limit was reached, new publications would result in
the oldest message being dropped.

In addition a further option would prevent the replacement of oldest by newest
message when a client was processing the messages. Publication would fail in
this state.

Comment 1 Gordon Sim 2008-04-09 15:33:21 UTC

The objective of the second option above is to prevent 'gaps' appearing in the
sequence seen by the consuming client.

Comment 2 Sergei Vorobiev 2008-06-19 14:28:45 UTC

otherwise the ring queue is expected to have the same basic features as a
regular queue (such as acquire modes, transactional delivery, ability to
cluster, transient vs durable, etc)

Comment 3 Gordon Sim 2008-09-30 14:44:16 UTC

There are two 'policy types' through which these features are delivered, these and the desired limits, are passed as name-value pairs in the arguments parameter to the queue.declare command used to create the queue.

qpid.policy_type=ring will cause the queue to delete the oldest message when an enqueue would otherwise breach the configured queue limit.

qpid.policy_type=ring_strict does the same, but if the oldest message has been delivered to a client but not yet acknowledged, it will not be removed to make way for new messages and the attempted enqueue will result in a failure.

The limit is set through either qpid.max_size (the total size of all messages on the queue) or qpid.max_count (the number of messages on the queue).

The functionality is covered by the QueuePolicyTests suite in Qpid, particularly the testRingPolicy and testStrictRingPolicy test cases.

Test strategy:

Case 1:
1.1. configure a queue with qpid.policy_type=ring, qpid.count=5
1.2. publish 10 distinct messages
1.3. read the messages from the queue and verify that only the last five were delivered

Case 2:

As for case 1, but using qpid.policy_type=ring_strict in step 1

Case 3:

1. configure a queue with qpid.policy_type=ring_strict, qpid.count=5
2. publish 5 messages
3. subscribe to queue and receive but do not ack all 5 messages
4. attempt to publish a further message which should fail

Case 4:

Comment 5 David Sommerseth 2008-12-16 12:53:33 UTC

Wrote test program in Python (cvs:/cvs/dist/tests/distribution/MRG_Messaging/qpid_test_ring_queue_bz441700/)

Test result show that ring queues are implemented according to expectations comment#3 ... One remark regarding test case 4 (D), the description is wrong - the policy type should be 'ring' and not 'ring_strict'.  This is checked with Gordon.

Test result:

$ ./bz441700.py
----> TEST-A - Policy: ring  -  Ring size: 5  - Using queue name: ringq_testA_ring_5
        Sending: ring test A ... message 1/10
        Sending: ring test A ... message 2/10
        Sending: ring test A ... message 3/10
        Sending: ring test A ... message 4/10
        Sending: ring test A ... message 5/10
        Sending: ring test A ... message 6/10
        Sending: ring test A ... message 7/10
        Sending: ring test A ... message 8/10
        Sending: ring test A ... message 9/10
        Sending: ring test A ... message 10/10
        Received: ring test A ... message 6/10
        Received: ring test A ... message 7/10
        Received: ring test A ... message 8/10
        Received: ring test A ... message 9/10
        Received: ring test A ... message 10/10
        Message queue is empty
        Got the expected number of messages
====> TEST-A - PASS

----> TEST-B - Policy: ring_strict  -  Ring size: 5  - Using queue name: ringq_testB_ring_strict_5
        Sending: ring test B ... message 1/10
        Sending: ring test B ... message 2/10
        Sending: ring test B ... message 3/10
        Sending: ring test B ... message 4/10
        Sending: ring test B ... message 5/10
        Sending: ring test B ... message 6/10
        Sending: ring test B ... message 7/10
        Sending: ring test B ... message 8/10
        Sending: ring test B ... message 9/10
        Sending: ring test B ... message 10/10
        Received: ring test B ... message 6/10
        Received: ring test B ... message 7/10
        Received: ring test B ... message 8/10
        Received: ring test B ... message 9/10
        Received: ring test B ... message 10/10
        Message queue is empty
        Got the expected number of messages
====> TEST-B - PASS

----> TEST-C - Policy: ring_strict  -  Ring size: 5  - Using queue name: ringq_testC_ring_strict_5
        Sending: ring test C.1 ... message 1/5
        Sending: ring test C.1 ... message 2/5
        Sending: ring test C.1 ... message 3/5
        Sending: ring test C.1 ... message 4/5
        Sending: ring test C.1 ... message 5/5
----> Receiving 5 messages, acking 2
        Received: ring test C.1 ... message 1/5
        ** Message acked
        Received: ring test C.1 ... message 2/5
        ** Message acked
        Received: ring test C.1 ... message 3/5
        Received: ring test C.1 ... message 4/5
        Received: ring test C.1 ... message 5/5
        Message queue is empty
        Got the expected number of messages
----> Sending 5 new messages
        Sending: ring test C.2 ... message 1/5
        Sending: ring test C.2 ... message 2/5
        Sending: ring test C.2 ... message 3/5
ERROR:  Could not send messages
====> Sending 5 new messages, failed as expected -- TEST-C PASS

----> TEST-D - Policy: ring  -  Ring size: 5  - Using queue name: ringq_testD_ring_5
        Sending: ring test D.1 ... message 1/5
        Sending: ring test D.1 ... message 2/5
        Sending: ring test D.1 ... message 3/5
        Sending: ring test D.1 ... message 4/5
        Sending: ring test D.1 ... message 5/5
----> Receiving 5 messages, acking 2
        Received: ring test D.1 ... message 1/5
        ** Message acked
        Received: ring test D.1 ... message 2/5
        ** Message acked
        Received: ring test D.1 ... message 3/5
        Received: ring test D.1 ... message 4/5
        Received: ring test D.1 ... message 5/5
        Message queue is empty
        Got the expected number of messages
----> Sending 5 new messages
        Sending: ring test D.2 ... message 1/5
        Sending: ring test D.2 ... message 2/5
        Sending: ring test D.2 ... message 3/5
        Sending: ring test D.2 ... message 4/5
        Sending: ring test D.2 ... message 5/5
====> Sent 5 messages - TEST-D PASS


SUMMARY:
        Score: 0 (0 = no errors)
        Overall result: PASS

Comment 7 errata-xmlrpc 2009-02-04 15:36:07 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHEA-2009-0035.html