Subscribing non persistent topic error if cluster disallow auto subscription creation

[dragonls]

Describe the bug
I am trying to use non persistent topic on pulsar 2.7.2 non persistent topic. Pulsar cluster disallow auto subscription creation, allowAutoSubscriptionCreation=false.

I tried to create subscription using pulsar admin api but receiving error Create subscription on non-persistent topic can only be done through client

To Reproduce
Steps to reproduce the behavior:

1. Delopy a Pulsar cluster with allowAutoSubscriptionCreation=false
2. Create a non persistent topic non-persistent://test/test/topic1
3. Create a consumer to subscribe the topic
4. See error

Expected behavior
The consumer can subscribe the non persistent topic correctly.

Additional context
The pulsar admin disallow creating subscription on non persistent topic:

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/v2/PersistentTopics.java

Lines 1347 to 1350 in 016fb87

	if (!topicName.isPersistent()) {
	throw new RestException(Response.Status.BAD_REQUEST, "Create subscription on non-persistent topic"
	+ "can only be done through client");
	}

The broker reject the subscription:

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/ServerCnx.java

Lines 1013 to 1022 in 016fb87

	boolean rejectSubscriptionIfDoesNotExist = isDurable
	&& !service.isAllowAutoSubscriptionCreation(topicName.toString())
	&& !topic.getSubscriptions().containsKey(subscriptionName);
	if (rejectSubscriptionIfDoesNotExist) {
	return FutureUtil
	.failedFuture(
	new SubscriptionNotFoundException(
	"Subscription does not exist"));
	}

[shibd]

Hi, Why create subscription on non persistent topic is not support by admin api? @hangc0276

[dragonls]

Hi, Why create subscription on non persistent topic is not support by admin api? @hangc0276

Relative issue: #7397

[codelipenghui]

@shibd For the non-persistent topic, the broker will not hold any messages. It looks like a message is forwarded between channels, from the producer channel to the consumer channel, so it does not make sense to create a subscription without a connected consumer