[Bug][java-client] No Retry when subscribing to topic via pattern

[mgrenonville]

Search before asking

• I searched in the issues and found nothing similar.

Version

v2.9.3 is working,
v2.9.4, v2.10.x, v2.11.x aren't

Minimal reproduce step

Here is a sample main code that illustrate issue:

import org.apache.pulsar.client.api.PulsarClient;
import org.apache.pulsar.client.api.PulsarClientException;

public class Main {
    public static void main(String[] args) throws PulsarClientException {

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

        client.newConsumer().topicsPattern("public/default/.*").subscriptionName("test").subscribe();

    }
}

With client in version 2.9.3, you will see theses logs

Failed to open connection to unresolvable.service:6650 : org.apache.pulsar.shade.io.netty.resolver.dns.DnsResolveContext$SearchDomainUnknownHostException: Failed to resolve 'unresolvable.service' and search domain query for configured domains failed as well: [.]
...
[namespace: public/default] Could not get connection while getTopicsUnderNamespace -- Will try again in 1459 ms
multiple retry until timeout

With 2.9.4, you only have the first error, the future is never resolved, and the scheduled runnable is never run.

The behavior is different with non pattern subscription, that retry until address resolves.

What did you expect to see?

Same behavior as in v2.9.3

What did you see instead?

See minimal step, uncompleted future when subscribing a multiple topic consumer.

Anything else?

I've read commits between v2.9.3 and v2.9.4 and my guess is that d9211c9 may be responsible

Are you willing to submit a PR?

• I'm willing to submit a PR!

[mgrenonville]

If my guess is correct it might even be a simple class cast exception not catched nor logged by future when casting executor to scheduled executor

My PR fixes 2.9.4 however, I've not tested on master