wuYin opened a new pull request #426: URL: https://github.com/apache/pulsar-client-go/pull/426
### Issue If user provided retry topic is same with consumer topic - Currently underlayer will create 2 same topic consumers to implement retry, but it's unnecessary, client-java only initialize one consumer to implement retry, see [ConsumerBuilderImpl.java#L139](https://github.com/apache/pulsar/blob/master/pulsar-client/src/main/java/org/apache/pulsar/client/impl/ConsumerBuilderImpl.java#L139) - When user invoke `consumer.Close()`, only the 2th consumer will be closed directly, consumer 1st is still active, there are potential memory leak. ### Cause MultiTopicConsumer is using `map[topic]consumer` to manage consumers, but in the above case, only 2th consumer will be corresponded with the topic, the 1st dosen't since map overwriting, it means 1st isn't managed by multiTopicConsumer , see [consumer_multitopic.go#L66](https://github.com/apache/pulsar-client-go/blob/master/pulsar/consumer_multitopic.go#L66) ### Reproducation ```go func main() { client, _ := pulsar.NewClient(pulsar.ClientOptions{URL: "pulsar://localhost:6650"}) defer client.Close() topic := "topic-01" consumer, _ := client.Subscribe(pulsar.ConsumerOptions{ Topic: topic, SubscriptionName: "my-sub", Type: pulsar.Shared, RetryEnable: true, DLQ: &pulsar.DLQPolicy{ RetryLetterTopic: topic, MaxDeliveries: 2, }, }) consumer.Close() } ``` - issue: consumer 1 created but not close directly, it will be closed before client closing. - log ``` INFO[0000] [Connected consumer] consumerID=1 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" INFO[0000] [Created consumer] consumerID=1 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" INFO[0000] [Connected consumer] consumerID=2 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" INFO[0000] [Created consumer] consumerID=2 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" INFO[0000] Closing consumer=[2] consumerID=2 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" INFO[0000] [Closed consumer] consumerID=2 name=pzxfg subscription=my-sub topic="persistent://public/default/topic-01" ---end ``` ### Motivation - Deduplicate user topics before using them, just like client-java's `TreeSet` topics implementation, see [ConsumerConfigurationData.java#L56](https://github.com/apache/pulsar/blob/master/pulsar-client/src/main/java/org/apache/pulsar/client/impl/conf/ConsumerConfigurationData.java#L56) ### Modifications - add `distinct` utility function to deduplicate user provided topics ### Verifying this change - [ ] Make sure that the change passes the CI checks. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
