I'm working on some monitoring tools for Kafka, and I've seen a couple of clusters get into a state where ClientUtils.fetchTopicMetadata will show that not all replicas are in the ISR.
At the same time, ZkUtils.getLeaderIsrAndEpochForPartition will show that all all partitions are in the ISR, and the "kafka.server":name="UnderReplicatedPartitions",type="ReplicaManager" MBean will report 0. What's going on? Is there something wrong with my controller, or should I not be paying attention to ClientUtils.fetchTopicMetadata? Thanks, Ryan
