[
https://issues.apache.org/jira/browse/KAFKA-3068?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15084507#comment-15084507
]
Jun Rao commented on KAFKA-3068:
--------------------------------
Yes, without this caching, in theory, this is still possible. However, the
window won't be long since the migrated broker will be removed on the next
metadata refresh, which will either happen periodically, or when one of the
existing connections is lost.
> 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)
