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Kafka, mail # user - ways to exit the blocking iterator


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ways to exit the blocking iterator
Milind Parikh 2012-02-28, 13:29
I need to exit the blocking consumer iterator on certain conditions ; do
some other processing and then resume the blocking iterartor. All of the
work is dependent on the "other processing".

Upon looking at the code, it seems that
https://svn.apache.org/repos/asf/incubator/kafka/trunk/core/src/main/scala/kafka/consumer/ConsumerIterator.scala
can take a shutdown command that will trigger the iterator to come out of
the blocking state.

Two Questions....
(a) Is there some sample code  that will issue this shutdown command?
(b) Is there any implication to the semantics of the queue that this
iterator is blocking on ?

(for example)

Message_1
Message_2
SHUTDOWN
Message_3
Message_4

should ideally deliver a unblock message to  the iterator and then continue
delivering the messages to the queue ; and by implication; to the consumer
iterator (of course, in 0.7, also recreating the MessageStream due to the
timeout issue)

Regards
Milind