[Fix] Fix the data race of ackReq.err

[Gleiphir2769]

Master Issue: #879

Motivation

#879 shows ackReq.err has data race problem.

Read

pulsar-client-go/pulsar/consumer_partition.go

Lines 471 to 473 in 44b64aa

	return ackReq.err
	}

Write

pulsar-client-go/pulsar/consumer_partition.go

Lines 702 to 707 in 44b64aa

	err := pc.client.rpcClient.RequestOnCnxNoWait(pc._getConn(), pb.BaseCommand_ACK, cmdAck)
	if err != nil {
	pc.log.Error("Connection was closed when request ack cmd")
	req.err = err
	}
	}

After ackReq.doneCh has introduced in #777 , I think the final return value of AckId can be nil. Because ackReq.err may not necessarily be set before the AckID returns. If user need to know the result of ack, just using AckIDWithResponse will be fine.

Modifications

Modify the return value of AckID.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

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

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

[Gleiphir2769]

/pulsarbot run-failure-checks

[Gleiphir2769]

/pulsarbot run-failure-checks

[Gleiphir2769]

/pulsarbot run-failure-checks

[nodece]

@Gleiphir2769 I think we should return this error, do you have any other way to fix this?

[Gleiphir2769]

@Gleiphir2769 I think we should return this error, do you have any other way to fix this?

@nodece Hi, thanks for your opinion. I think this error doesn't matter.

This error is set in another goroutine internalAck. When AckId returns, internalAck is not necessarily executing. It means that if internalAck really fails, the ackReq.err returned by AckId may still be nil instead of actual err.

After #777 , AckId has been specified as an async method. AckIDWithResponse should be called If user really need to know the ack result,.

[Gleiphir2769]

@wolfstudy Hi, could you give a review when you r free?