[improve] change RoutingMode default from UseSinglePartition to RoundRobinDistribution

[TakaHiR07]

Motivation

It is more reasonable to set routingMode default RoundRobinDistribution, just as the java client.

Otherwise, user may ignore this config, and producer can not produce msg to all partitions

Modifications

change default routingMode config

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial rework / code cleanup without any test coverage.

Documentation

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[eolivelli]

I agree that we should align the default with the Java client

can you please add a test case ?

This is breaking behaviour change, we should discuss it on the mailing list and we should also take care of not cherry-pick it on maintenance branches, such kind of changes is allowed only on major versions

[BewareMyPower]

I agree with @eolivelli. It would be good to fix the inconsistency with the Java client, but it would also bring breaking changes. We should discuss it on the mailing list.

[TakaHiR07]

I agree that we should align the default with the Java client

can you please add a test case ?

This is breaking behaviour change, we should discuss it on the mailing list and we should also take care of not cherry-pick it on maintenance branches, such kind of changes is allowed only on major versions

Have modified the configuration test to verify default config change. It seems not necessary to add additional test because testRoundRobinRoutingPolicy() is included.

[BewareMyPower]

Hi, @TakaHiR07 is there any chance to resolve the conflicts?

[TakaHiR07]

Hi, @TakaHiR07 is there any chance to resolve the conflicts?

@BewareMyPower done.

[BewareMyPower]

It seems that there are some existing tests that failed due to this change.

Unit tests failed

[TakaHiR07]

I revert the pr change and this test "testHasMessageAvailableAfterSeekToEnd" still fail. It seems this pr is not the reason