Support delete inactive topic when subscriptions caught up

[codelipenghui]

Motivation

Currently, pulsar support delete inactive topic which has no active producers and no subscriptions. This pull request is support to delete inactive topics that all subscriptions of the topic are caught up and no active producers/consumer.

Modifications

Expose inactive topic delete mode in broker.conf, future more we can support namespace level configuration for the inactive topic delete mode.

Verifying this change

New unit tests added for each inactive topic delete mode.

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (no)
• Anything that affects deployment: (no)

Documentation

• Does this pull request introduce a new feature? (no)

[codelipenghui]

run integration tests

[codelipenghui]

run java8 tests
run integration tests

[codelipenghui]

run cpp tests

[sijie]

@codelipenghui overall looks good. however we need to take care of two things:

1. the backward compatibility of the newly introduced setting.
2. what is the "inactive" behavior for subscriptions all caught up? IMO A topic should be treated as an inactive topic in delete_when_subscriptions_caught_up mode when meet all the following conditions:

a) no messages published for a while (larger than the max inactive duration).
b) no producers connected to this topic.
c) no backlog.

I don't think we need to check if there are consumers connected.

---

Also I noticed that you indicated that this pull request fixes #4824. However I don't think this pull request fixes the problem in #4824. So that would be considered to remove from the description. Otherwise when we close this pull request, it will accidentally close #4824

[codelipenghui]

@sijie I have addressed your comments, please help take a look.

[sijie]

@codelipenghui the change looks good to me.

I labeled this issue as doc-required. Can you create a follow-up issue of adding documentation for these newly introduced features?

[codelipenghui]

@sijie I have create issue #6087 to track the document for this PR and update the description of this PR.

[tuteng]

Add label release-2.5.1, due #6310 dependency

[Anonymitaet]

Doc has been added: https://pulsar.apache.org/docs/en/next/reference-configuration/#broker

[truong-hua]

@codelipenghui overall looks good. however we need to take care of two things:

1. the backward compatibility of the newly introduced setting.
2. what is the "inactive" behavior for subscriptions all caught up? IMO A topic should be treated as an inactive topic in delete_when_subscriptions_caught_up mode when meet all the following conditions:

a) no messages published for a while (larger than the max inactive duration). b) no producers connected to this topic. c) no backlog.

I don't think we need to check if there are consumers connected.

Also I noticed that you indicated that this pull request fixes #4824. However I don't think this pull request fixes the problem in #4824. So that would be considered to remove from the description. Otherwise when we close this pull request, it will accidentally close #4824

I agree that we not include the condition that consumers have to be inactive. The consumers usually be keep running to provide low latency message processing and so they are always active as much as possible, which will prevent the inactive topic to be cleaned up.