Jon Bates created KAFKA-7192:
--------------------------------

             Summary: State-store can desynchronise with changelog
                 Key: KAFKA-7192
                 URL: https://issues.apache.org/jira/browse/KAFKA-7192
             Project: Kafka
          Issue Type: Bug
          Components: streams
    Affects Versions: 1.1.1
            Reporter: Jon Bates


n.b. this bug has been verified with exactly-once processing enabled

Consider the following scenario:
 * A record, N is read into a Kafka topology
 * the state store is updated
 * the topology crashes

h3. *Expected behaviour:*
 # Node is restarted
 # Offset was never updated, so record N is reprocessed
 # State-store is reset to position N-1
 # Record is reprocessed

h3. 
[|https://github.com/spadger/kafka-streams-sad-state-store#actual-behaviour]*Actual
 Behaviour*
 # Node is restarted
 # Record N is reprocessed (good)
 # The state store has the state from the previous processing

I'd consider this a corruption of the state-store, hence the critical Priority, 
although High may be more appropriate.

I wrote a proof-of-concept here, which demonstrates the problem on Linux:

https://github.com/spadger/kafka-streams-sad-state-store



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to