[Bug] `bin/pulsar-admin topics subscriptions` freeze if namespace not exists

[labuladong]

Search before asking

• I searched in the issues and found nothing similar.

Version

Master version of Pulsar.

Minimal reproduce step

1. start standalone:

bin/pulsar standalone --num-bookies 2

2. query subscriptions with a nonexistent namespace name:

bin/pulsar-admin topics subscriptions persistent://public/not-exist-namespace/my-topic

What did you expect to see?

Namespace not found error.

What did you see instead?

Freeze until timeout.

null

Reason: java.util.concurrent.TimeoutException
2022-11-16T17:30:44,445+0800 [main] WARN  org.apache.pulsar.common.util.ShutdownUtil - Triggering immediate shutdown of current process with status 1
java.lang.Exception: Stacktrace for immediate shutdown
	at org.apache.pulsar.common.util.ShutdownUtil.triggerImmediateForcefulShutdown(ShutdownUtil.java:52) ~[org.apache.pulsar-pulsar-common-2.11.0-SNAPSHOT.jar:2.11.0-SNAPSHOT]
	at org.apache.pulsar.admin.cli.PulsarAdminTool.exit(PulsarAdminTool.java:309) ~[org.apache.pulsar-pulsar-client-tools-2.11.0-SNAPSHOT.jar:2.11.0-SNAPSHOT]
	at org.apache.pulsar.admin.cli.PulsarAdminTool.main(PulsarAdminTool.java:300) ~[org.apache.pulsar-pulsar-client-tools-2.11.0-SNAPSHOT.jar:2.11.0-SNAPSHOT]

Anything else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!