Consumer cannot consume messages when key_shared mode and subscriptionKeySharedUseConsistentHashing

[sourcelliu]

Describe the bug
Key_shared mode is configured as ConsistentHashingStickyKeyConsumerSelector, When I use three consumers with the same consumerName, if one consumer is closed, the other two consumers will no longer be able to consume messages.

To Reproduce
Steps to reproduce the behavior:

1. config the 'conf/standalone.conf'

    subscriptionKeySharedUseConsistentHashing=true
   

2. ./bin/pulsar standalone
3. Start 3 consumers with the same cosumerName.

        PulsarClient client = PulsarClient.builder()
                .serviceUrl("pulsar://localhost:6650")
                .build();

        org.apache.pulsar.client.api.Consumer consumer = client.newConsumer()
                .topic("my-topic")
                .subscriptionName("my-subscription")
                .consumerName("one")
                .subscriptionType(SubscriptionType.Key_Shared)
                .subscribe();

4. Start a producer send messages.
5. All 3 consumers can consume messages.
6. Close one consumer, and the producer send messages again.
7. The other two consumers cannot consume new messages

Expected behavior
The other two consumers can continue to consume new messages(Refer to step 7 above).

Additional context

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/ConsistentHashingStickyKeyConsumerSelector.java

Line 93 in e19f647

v.removeIf(c -> c.consumerName().equals(consumer.consumerName()));

I think the problem is due to the above code, which removes all consumers with the same name.

[lhotari]

Perhaps this is related to #13965 ?

[merlimat]

@sourcelliu @lhotari

Perhaps this is related to #13965 ?

No, it's not related to that (and #13965 is just a test issue, not a code issue).

The consumer name is expected to be unique (eg: if you don't pass one, it will be auto-generated).

Having said that, the check here is wrong, as we should compare the consumer instance and not just the name.