[broker] Key_Shared dispatcher with no connected consumers should be recreated if allowOutOfOrderDelivery changes

[massakam]

Motivation

PersistentStickyKeyDispatcherMultipleConsumers has an instance variable named allowOutOfOrderDelivery, which is set by the first connected consumer and will not change unless the dispatcher is closed, such as by unloading. That is, end users have no way to change this setting.

As with keySharedMode, if a consumer with a different policy connects after all consumers have been disconnected, the dispatcher should be closed and recreated.

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentSubscription.java

Lines 272 to 280 in dac47cb

	KeySharedMeta ksm = consumer.getKeySharedMeta();
	KeySharedMode keySharedMode = ksm.getKeySharedMode();
	if (dispatcher == null || dispatcher.getType() != SubType.Key_Shared
	|| ((PersistentStickyKeyDispatcherMultipleConsumers) dispatcher).getKeySharedMode()
	!= keySharedMode) {
	previousDispatcher = dispatcher;
	dispatcher = new PersistentStickyKeyDispatcherMultipleConsumers(topic, cursor, this,
	topic.getBrokerService().getPulsar().getConfiguration(), ksm);
	}

Modifications

If a consumer with a different keySharedMode or allowOutOfOrderDelivery policy tries to connect to PersistentStickyKeyDispatcherMultipleConsumers to which no consumer is connected, close that dispatcher and create a new one.

Verifying this change

• Make sure that the change passes the CI checks.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (no)
• Anything that affects deployment: (no)

Documentation

• no-need-doc