This change is 

pkg/ccl/changefeedccl/sink_kafka.go line 211 at r1 (raw file):

	// where our call to Flush() would block forever.
	if (c.Flush.Bytes > 0 || c.Flush.Messages > 1) && c.Flush.Frequency == 0 {
		return errors.New("Flush.Frequency must be > 0 when Flush.Bytes > 0 or Flush.Messages > 1")

Sarama does the check for this here - it checks for c.Flush.Messages > 0 rather than c.Flush.Messages > 1 which I thought makes more sense.

https://github.com/IBM/sarama/blob/25c9c1a880e385781e1a39b49f8e7239e3d5e729/config.go#L593-L595

pkg/ccl/changefeedccl/sink_kafka.go line 211 at r1 (raw file):

I just realized that sarama doesn't return an error in this case but just outputs a warning https://github.com/IBM/sarama/blob/25c9c1a880e385781e1a39b49f8e7239e3d5e729/config.go#L594. I will the validation back. It does return error for improper client id though. I will add a test for this in the other PR.

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

pkg/ccl/changefeedccl/sink_kafka.go line 211 at r1 (raw file):

Done.

TFTRs!!

bors r=rharding6373

Build succeeded:

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