KAFKA-12989: MockClient should respect the request matcher passed to prepareUnsupportedVersionResponse

[kirktrue]

Handle the case where matches returns false and throw the InvalidStateException as stated by the JavaDoc.

We need to guard against this unexpected runtime error in the KafkaAdminClient's sendEligibleCalls method with a try/catch. Not 100% sure if that's kosher or not.

Included a targeted unit test for this case. The remaining tests in KafkaAdminTestClient continue to pass.

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[kirktrue]

@hachikuji - would you be willing to assign a reviewer for this PR?

The failing tests look like they're related to KRaft tests, so I don't think they're related.

[kirktrue]

@cmccabe - could you take a look at this and/or assign a reviewer for this? Thanks!

[cmccabe]

Why is NetworkClient#send throwing an exception? It shouldn't be doing that, right? Can you explain more about the problem that this PR fixes?

[kirktrue]

Why is NetworkClient#send throwing an exception? It shouldn't be doing that, right? Can you explain more about the problem that this PR fixes?

Per the original issue the MockClient used for testing allows for fault injection via the RequestMatcher. If the test sets up the condition where the request doesn't match some condition, the MockClient.send method is supposed to throw an IllegalStateException.

That change seemed straightforward except that this now caused problems in KafkaAdminClient. Because it's not expecting any errors, this exception causes the thread in KafkaAdminClient.sendEligibleCalls that is servicing requests to die, hence my addition of the try/catch wrapper.

That said, I'm not 100% confident that this change is the right way to handle things. Please advise.

Thanks!