[AMQ-3607] Setting OptimiseAcknowledge on a queue with a prefetch limit causes normal/fast consumers to miss messages when a slow consumer is blocking

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 5.5.0
• Fix Version/s: 5.6.0
• Component/s: Broker

Environment

Java: 1.6.0_26-b03-383.jdk

• Assignee: Gary Tully
• Reporter: James Furness
• Created: 23/Nov/11 18:17
• Updated: 22/Jan/12 23:25
• Resolved: 29/Nov/11 19:58

Description

The attached test case tests slow consumer handling with a variety of topic policies and SessionFactory/ConnectionFactory settings. The expectation is that a normal (i.e. fast) consumer will continue to receive messages whilst a slow consumer is blocking.

Without a prefetch limit, the expected behaviour is seen with setOptimizeAcknowledge both true and false.

If a prefetch limit is set, setOptimizeAcknowledge(true) causes the normal/fast consumer to miss messages whilst the slow consumer is blocking.

Would be nice to be able to turn on OptimiseAcknowledge for performance reasons, however it is also necessary to set the prefetch limit in order to trigger SlowConsumerStrategy/MessageEvictionStrategySupport logic.

testDefaultSettings

Publisher: Send 0
SlowConsumer: Receive 0
FastConsumer: Receive 0
testDefaultSettings: Publisher Sent: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testDefaultSettings: Whilst slow consumer blocked:
		- SlowConsumer Received: 1 [0]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testDefaultSettings: After slow consumer unblocked:
		- SlowConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]

testDefaultSettingsWithOptimiseAcknowledge

testDefaultSettingsWithOptimiseAcknowledge: Publisher Sent: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testDefaultSettingsWithOptimiseAcknowledge: Whilst slow consumer blocked:
		- SlowConsumer Received: 1 [0]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testDefaultSettingsWithOptimiseAcknowledge: After slow consumer unblocked:
		- SlowConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]

testBounded

testBounded: Publisher Sent: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testBounded: Whilst slow consumer blocked:
		- SlowConsumer Received: 1 [0]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testBounded: After slow consumer unblocked:
		- SlowConsumer Received: 10 [0, 1, 2, 3, 4, 25, 26, 27, 28, 29]
		- FastConsumer Received: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]

testBoundedWithOptimiseAcknowledge

testBoundedWithOptimiseAcknowledge: Publisher Sent: 30 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
testBoundedWithOptimiseAcknowledge: Whilst slow consumer blocked:
		- SlowConsumer Received: 1 [0]
		- FastConsumer Received: 5 [0, 1, 2, 3, 4]
testBoundedWithOptimiseAcknowledge: After slow consumer unblocked:
		- SlowConsumer Received: 5 [0, 1, 2, 3, 4]
		- FastConsumer Received: 5 [0, 1, 2, 3, 4]

java.lang.AssertionError: Fast consumer missed messages whilst slow consumer was blocking expected:<[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]> but was:<[0, 1, 2, 3, 4]>

Issue Links

• relates to: AMQ-3676 Setting OptimizeAcknowledge on a consumer with a small prefetch size appears to prevent messages from being acknowledged