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https://issues.apache.org/jira/browse/KAFKA-3981?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Matthias J. Sax resolved KAFKA-3981.
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Resolution: Not A Problem
> Possible race condition between controller cache and ZK on topic delete
> -----------------------------------------------------------------------
>
> Key: KAFKA-3981
> URL: https://issues.apache.org/jira/browse/KAFKA-3981
> Project: Kafka
> Issue Type: Bug
> Reporter: Matthias J. Sax
> Priority: Minor
>
> In an integration test, I delete some topics and check with the following
> code if the topics got deleted:
> {noformat}
> final Set<String> expectedTopics = new HashSet<>();
> expectedTopics.add(INPUT_TOPIC);
> expectedTopics.add(INTERMEDIATE_USER_TOPIC);
> expectedTopics.add(OUTPUT_TOPIC);
> expectedTopics.add("__consumer_offsets");
> Set<String> allTopics;
> ZkUtils zkUtils = null;
> try {
> zkUtils = ZkUtils.apply(CLUSTER.zKConnectString(),
> 30000,
> 30000,
> JaasUtils.isZkSecurityEnabled());
> do {
> allTopics = new HashSet<>();
>
> alllTopics.addAll(scala.collection.JavaConversions.seqAsJavaList(zkUtils.getAllTopics()));
> } while (allTopics.size() != expectedTopics.size());
> } finally {
> if (zkUtils != null) {
> zkUtils.close();
> }
> }
> assertThat(allTopics, equalTo(expectedTopics));
> {noformat}
> However, after the loop terminates (and {{assertThat}} passes), I try to
> re-create one of the deleted topics I get:
> {noformat}
> java.lang.IllegalStateException: Partition
> [cleanup-integration-test-KSTREAM-MAP-0000000011-repartition,0] should be in
> the NonExistentPartition states before moving to NewPartition state. Instead
> it is in OnlinePartition state
> {noformat}
> After discussion with [~guozhang] I got the following answer:
> bq. I think I know the reason: the zk path of the topic is deleted by the
> background delete thread (see completeDeleteTopic in TopicDeletionManager),
> and once that is done, zkUtils.getAllTopics() will not have this topic any
> more;But the controller cache will only be clear this entry after that, by
> triggering the listener on this zk path, so there is still a window of race
> condition that the controller still have this entry in metadata.
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