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Matthias J. Sax commented on KAFKA-6687: ---------------------------------------- One side remark about this ticket: if we allow to read a topic multiple times, we need to make sure that the provided config does not contradict each other. For example, users could set two different auto-offset-reset policies. We need to detect those cases and raise an exception. > Allow to read a topic multiple times > ------------------------------------ > > Key: KAFKA-6687 > URL: https://issues.apache.org/jira/browse/KAFKA-6687 > Project: Kafka > Issue Type: Improvement > Components: streams > Reporter: Matthias J. Sax > Priority: Major > > Users often want to read topic multiple times. However, this is not possible > because there is a single consumer and thus a topic can only be consumed once. > Users get an exception > {quote}Exception in thread “main” > org.apache.kafka.streams.errors.TopologyException: Invalid topology: Topic > source has already been registered by another source. > {quote} > If they use a topic name in multiple `stream()`, `table()`, `globalTable()` > calls. > However, with KAFKA-6034 in place, we could allow adding a topic multiple > times and rewrite the topology internally to only read the topic once. This > would simplify application code as users don't need to put workaround in > place to get the same behavior. -- This message was sent by Atlassian JIRA (v7.6.3#76005)