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Eno Thereska commented on KAFKA-3068: ------------------------------------- [~ijuma], [~hachikuji]: I think a proper solution would make use of a cluster identity in addition to broker id+host. The problems with using bootstrap brokers is that 1) users might not specify enough bootstrap brokers and 2) bootstrap brokers can also move to a different cluster as [~ijuma] points out. While the windows of vulnerability will be small as [~junrao] points out, it will still be a problem. One option would be to query zookeeper (which is the cluster identity in a way) and get the latest brokers from it instead of caching them in the client. > NetworkClient may connect to a different Kafka cluster than originally > configured > --------------------------------------------------------------------------------- > > Key: KAFKA-3068 > URL: https://issues.apache.org/jira/browse/KAFKA-3068 > Project: Kafka > Issue Type: Bug > Components: clients > Affects Versions: 0.9.0.0 > Reporter: Jun Rao > > In https://github.com/apache/kafka/pull/290, we added the logic to cache all > brokers (id and ip) that the client has ever seen. If we can't find an > available broker from the current Metadata, we will pick a broker that we > have ever seen (in NetworkClient.leastLoadedNode()). > One potential problem this logic can introduce is the following. Suppose that > we have a broker with id 1 in a Kafka cluster. A producer client remembers > this broker in nodesEverSeen. At some point, we bring down this broker and > use the host in a different Kafka cluster. Then, the producer client uses > this broker from nodesEverSeen to refresh metadata. It will find the metadata > in a different Kafka cluster and start producing data there. -- This message was sent by Atlassian JIRA (v6.3.4#6332)