[improve][pip] PIP-425: Support connecting with next available endpoint for multi-endpoint serviceUrls

[AuroraTwinkle]

Fixes https://github.com/apache/pulsar/issues/22934#issuecomment-2943690398

Main Issue: https://github.com/apache/pulsar/issues/22934#issuecomment-2943690398

Implementation: https://github.com/apache/pulsar/pull/24387

Motivation

As https://github.com/apache/pulsar/issues/22934 and https://github.com/apache/pulsar/discussions/22933 mentioned, when most of the nodes in serviceurl are down (but there is at least one available node), creating consumers and producers through PulsarClient will most likely fail. I think this is not as expected. If the code is robust enough, as long as there is one available node, it should be accessible normally. Therefore, this pip is going to optimize the logic, remove unavailable nodes through the feedback mechanism, and improve the success rate of PulsarClient requests.

By the way, https://github.com/apache/pulsar/pull/22935 removes faulty nodes through a regular health check mechanism, but this brings new problems (frequent creation of connections and increased system load), so this solution is abandoned. See https://github.com/apache/pulsar/issues/22934#issuecomment-2943690398 for more details!

Modifications

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• [ ] Dependencies (add or upgrade a dependency)
• [x] The public API
• [ ] The schema
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• [ ] The threading model
• [ ] The binary protocol
• [ ] The REST endpoints
• [ ] The admin CLI options
• [ ] The metrics
• [ ] Anything that affects deployment

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[AuroraTwinkle]

Some initial feedback

@lhotari All good suggestions, I will fix them and update later. Thanks for your help!

[AuroraTwinkle]

Some initial feedback

Updated!

[AuroraTwinkle]

good progress! added some follow up comments

@lhotari Modified and updated as suggested. Thanks!

[AuroraTwinkle]

Hi @AuroraTwinkle

The proposal looks good to me. I’ve added a few comments to help clarify the problem and the proposed solution, making it easier to understand.

Ok, I will fix them later, Thanks!

[AuroraTwinkle]

Hi @AuroraTwinkle

The proposal looks good to me. I’ve added a few comments to help clarify the problem and the proposed solution, making it easier to understand.

@codelipenghui Very interesting and detailed suggestions, I have fixed them, thank you again!

[liangyepianzhou]

@lhotari @codelipenghui @315157973 We need more votes on the mailing list to close this PIP. Could you please help vote when you have a moment? https://lists.apache.org/thread/c2zvjwf7bqp8nc2rpzbxd4kdtztk23xp