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https://issues.apache.org/jira/browse/KAFKA-3727?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15301027#comment-15301027
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Edoardo Comar commented on KAFKA-3727:
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Thanks [~ijuma] those issues are related.
However [KAFKA-3177|https://issues.apache.org/jira/browse/KAFKA-3177] does not
mention poll() which is the most basic api call for a consumer.
And [KAFKA-2391|https://issues.apache.org/jira/browse/KAFKA-2391] mentions
adding timeouts as arguments in the API,
and such an argument is already present in KafkaConsumer.poll (timeout) .
This issue is that poll (timeout) will block FOREVER, when a consumer is
assigned a non non-existent TopicPartition.
> Consumer.poll() stuck in loop on non-existent topic manually assigned
> ---------------------------------------------------------------------
>
> Key: KAFKA-3727
> URL: https://issues.apache.org/jira/browse/KAFKA-3727
> Project: Kafka
> Issue Type: Bug
> Components: clients
> Reporter: Edoardo Comar
> Priority: Critical
>
> The behavior of a consumer on poll() for a non-existing topic is surprisingly
> different/inconsistent
> between a consumer that subscribed to the topic and one that had the
> topic-partition manually assigned.
> The "subscribed" consumer will return an empty collection
> The "assigned" consumer will *loop forever* - this feels a bug to me.
> sample snippet to reproduce:
> {quote}
> KafkaConsumer<String, String> assignKc = new KafkaConsumer<>(props1);
> KafkaConsumer<String, String> subsKc = new KafkaConsumer<>(props2);
> List<TopicPartition> tps = new ArrayList<>();
> tps.add(new TopicPartition("topic-not-exists", 0));
> assignKc.assign(tps);
> subsKc.subscribe(Arrays.asList("topic-not-exists"));
> System.out.println("********* subscribe k consumer ");
> ConsumerRecords<String, String> crs2 = subsKc.poll(1000L);
> print("subscribeKc", crs2); // returns empty
> System.out.println("********* assign k consumer ");
> ConsumerRecords<String, String> crs1 = assignKc.poll(1000L);
> // will loop forever !
> print("assignKc", crs1);
> {quote}
> the logs for the "assigned" consumer show:
> [2016-05-18 17:33:09,907] DEBUG Updated cluster metadata version 8 to
> Cluster(nodes = [192.168.10.18:9093 (id: 0 rack: null)], partitions = [])
> (org.apache.kafka.clients.Metadata)
> [2016-05-18 17:33:09,908] DEBUG Partition topic-not-exists-0 is unknown for
> fetching offset, wait for metadata refresh
> (org.apache.kafka.clients.consumer.internals.Fetcher)
> [2016-05-18 17:33:10,010] DEBUG Sending metadata request
> {topics=[topic-not-exists]} to node 0 (org.apache.kafka.clients.NetworkClient)
> [2016-05-18 17:33:10,011] WARN Error while fetching metadata with correlation
> id 9 : {topic-not-exists=UNKNOWN_TOPIC_OR_PARTITION}
> (org.apache.kafka.clients.NetworkClient)
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