Github user srdo commented on a diff in the pull request: https://github.com/apache/storm/pull/2593#discussion_r178562679 --- Diff: external/storm-kafka-client/src/main/java/org/apache/storm/kafka/spout/KafkaSpout.java --- @@ -570,20 +572,25 @@ public void ack(Object messageId) { // Only need to keep track of acked tuples if commits to Kafka are controlled by // tuple acks, which happens only for at-least-once processing semantics final KafkaSpoutMessageId msgId = (KafkaSpoutMessageId) messageId; - if (!emitted.contains(msgId)) { - if (msgId.isEmitted()) { + if (!msgId.isNullTuple()) { --- End diff -- Great, that sounds good.
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