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HaiyuanZhao resolved KAFKA-12789. --------------------------------- Resolution: Fixed > Remove Stale comments for meta response handling logic > ------------------------------------------------------ > > Key: KAFKA-12789 > URL: https://issues.apache.org/jira/browse/KAFKA-12789 > Project: Kafka > Issue Type: Improvement > Reporter: HaiyuanZhao > Assignee: HaiyuanZhao > Priority: Minor > > According to my understanding, the following paragraph looks like a stale > comments. > {code:java} > public void handleSuccessfulResponse(RequestHeader requestHeader, long now, > MetadataResponse response) { > ... > // Don't update the cluster if there are no valid nodes...the > topic we want may still be in the process of being > // created which means we will get errors and no nodes until it > exists > if (response.brokers().isEmpty()) { > log.trace("Ignoring empty metadata response with correlation > id {}.", requestHeader.correlationId()); > this.metadata.failedUpdate(now); > } else { > this.metadata.update(inProgress.requestVersion, response, > inProgress.isPartialUpdate, now); > } > ... > {code} > The comments above mean we will may get errors and no nodes if the topic we > want may still be in the process of being created. > However, every meta request will return all brokers from the logic of the > server side, just as followed > {code:java} > def handleTopicMetadataRequest(request: RequestChannel.Request): Unit = { > ... > val brokers = metadataCache.getAliveBrokers > ... > } > {code} > I studied the related git commit history and figured out why. > # This comments was first introduced in KAFKA-642 (e11447650a). which means > meta request only need brokers related to the topics we want. > # KAFKA-1535 (commitId: 4ebcdfd51f) changed the server side logic. which has > the metadata response contain all alive brokers rather than just the ones > needed for the given topics. > # However, this comments are retained till now. > So According to my understanding, this comments looks like a stale one and > can be removed. -- This message was sent by Atlassian Jira (v8.3.4#803005)