ReconsumeLater cause panic

[elvizlai]

Expected behavior

should be ReconsumeLater

Actual behavior

Panic when call ReconsumeLater

With version 0.6.0 https://github.com/apache/pulsar-client-go/blob/fe3b7c4e445b3de42974ca692574229ad9099a45/pulsar/consumer_impl.go?_pjax=%23js-repo-pjax-container%2C%20div%5Bitemtype%3D%22http%3A%2F%2Fschema.org%2FSoftwareSourceCode%22%5D%20main%2C%20%5Bdata-pjax-container%5D#L481

same panic for 0.7

github.com/apache/pulsar-client-go@v0.7.0-candidate-1.0.20211108044248-fe3b7c4e445b/pulsar/consumer_impl.go:481 +0x6ca

Steps to reproduce

	client, err := pulsar.NewClient(pulsar.ClientOptions{
		URL: addr,
	})
	if err != nil {
		panic(err)
	}

	consumer, err := client.Subscribe(pulsar.ConsumerOptions{
		Topic:            "test",
		SubscriptionName: "xyz",
	})
	if err != nil {
		panic(err)
	}

        for {
	        select {
	        case cm := <-consumer.Chan():
		        fmt.Println(string(cm.Payload()))
		        cm.ReconsumeLater(cm.Message,time.Second)
	        }
        }

System configuration

Pulsar version: 0.6.0

[cckellogg]

Can you share more of the stack trace? Does this happen every time you call ReconsumeLater? If not what are the steps to reproduce?

[elvizlai]

time

For missing DQL consumer, it will cause panic.

[leizhiyuan]

yes, you should have a dql, then you can ReconsumeLater

the panic maybe not friendly

	// ReconsumeLater mark a message for redelivery after custom delay
	ReconsumeLater(msg Message, delay time.Duration)

the better way ,we need return a error for this method.

[leizhiyuan]

you can use

consumer, err := client.Subscribe(pulsar.ConsumerOptions{
		Topic:            "topic-1",
		SubscriptionName: "my-sub",
		Type:             pulsar.Exclusive,
		DLQ:              &pulsar.DLQPolicy{MaxDeliveries: 1,DeadLetterTopic: "dlq-topic"},
	})

to solve this. it is helpful