Hi Enrico Olivelli
> It is good to help users to not fall into bad situations but on the other
case we cannot deal with many silly configurations that you could set up,
like creating a pipeline of functions that in the end create a cycle.
Sorry, this test just helps to reproduce the problem quickly. The reality
is that there is only one consumer, but every restart triggers this issue
and ends up with a topic like this:
"persistent://public/default/tp1-sub1-RETRY-sub1-RETRY-sub1-RETRY...."
> I wonder if we could simply document this fact instead of adding code
```java
Consumer<> consumer = pulsarClient.newConsumer()
.topicsPattern("my-property/my-ns/.*").subscriptionName("sub1")
.enableRetry(true)
```
With the client restarted, the code above will reproduce the problem.
On Sun, Feb 12, 2023 at 3:31 AM Enrico Olivelli <[email protected]> wrote:
> Yubiao,
>
> Il Sab 11 Feb 2023, 19:06 Yubiao Feng <[email protected]
> .invalid>
> ha scritto:
>
> > Hi community
> >
> > I am starting a DISCUSS for "Retry topic should not create for a retry
> > topic."
> >
> > If we use regex-topic consumer and enable retry, it is possible to create
> > such a topic
> > "persistent://public/default/tp1-sub1-RETRY-sub2-RETRY-sub3-RETRY....".
> You
> > can reproduce this by using the test below.
> >
> > It probably doesn't make sense to create a RETRY/DLQ topic on RETRY/DLQ.
> We
> > should avoid this scenario if users use the default configuration (users
> > can enable it if they need it).
> >
>
> I agree that this is a bad case.
> But should we really care?
>
> You must do it very intentionally.
> It is good to help users to not fall into bad situations but on the other
> case we cannot deal with many silly configurations that you could set up,
> like creating a pipeline of functions that in the end create a cycle.
>
>
> I wonder if we could simply document this fact instead of adding code
>
>
> Enrico
>
>
>
>
> > ```java
> > @Test
> > public void testRetryTopicWillNotCreatedForRetryTopic() throws
> > Exception {
> > final String topic = "persistent://my-property/my-ns/tp1";
> > Producer<byte[]> producer =
> pulsarClient.newProducer(Schema.BYTES)
> > .topic(topic)
> > .create();
> > for (int i = 0; i < 100; i++) {
> > producer.send(String.format("Hello Pulsar [%d]",
> > i).getBytes());
> > }
> > producer.close();
> >
> > for (int i =0; i< 10; i++) {
> > Consumer<byte[]> consumer =
> > pulsarClient.newConsumer(Schema.BYTES)
> > .topicsPattern("my-property/my-ns/.*")
> > .subscriptionName("sub" + i)
> > .enableRetry(true)
> >
> >
> .deadLetterPolicy(DeadLetterPolicy.builder().maxRedeliverCount(2).build())
> >
> > .subscriptionInitialPosition(SubscriptionInitialPosition.Earliest)
> > .subscribe();
> > Message<byte[]> message = consumer.receive();
> > log.info("consumer received message : {} {}",
> > message.getMessageId(), new String(message.getData()));
> > consumer.reconsumeLater(message, 1, TimeUnit.SECONDS);
> > consumer.close();
> > }
> >
> > Set<String> tps =
> >
> >
> pulsar.getBrokerService().getTopics().keys().stream().collect(Collectors.toSet());
> > try {
> > for (String tp : tps) {
> > assertTrue(howManyKeyWordRetryInTopicName(tp,
> > RETRY_GROUP_TOPIC_SUFFIX) <= 1, tp);
> > assertTrue(howManyKeyWordRetryInTopicName(tp,
> > DLQ_GROUP_TOPIC_SUFFIX) <= 1, tp);
> > }
> > } finally {
> > // cleanup.
> > for (String tp : tps){
> > if (tp.startsWith(topic)) {
> > admin.topics().delete(tp ,true);
> > }
> > }
> > }
> > }
> >
> > private int howManyKeyWordRetryInTopicName(String topicName, String
> > keyWord) {
> > int retryCountInTopicName = 0;
> > String tpCp = topicName;
> > while (true) {
> > int index = tpCp.indexOf(keyWord);
> > if (index < 0) {
> > break;
> > }
> > tpCp = tpCp.substring(index + keyWord.length());
> > retryCountInTopicName++;
> > }
> > return retryCountInTopicName;
> > }
> > ```
> >
> > Thanks
> > Yubiao Feng
> >
>
