[jira] [Created] (FLINK-6316) Kinesis connector docs should mention that FlinkKinesisConsumer does not provide strong ordering guarantees on resharding

[Shang Yuanchun (Jira)]

Tzu-Li (Gordon) Tai created FLINK-6316:
------------------------------------------

             Summary: Kinesis connector docs should mention that FlinkKinesisConsumer does not provide strong ordering guarantees on resharding
                 Key: FLINK-6316
                 URL: https://issues.apache.org/jira/browse/FLINK-6316
             Project: Flink
          Issue Type: Improvement
          Components: Documentation, Kinesis Connector
            Reporter: Tzu-Li (Gordon) Tai


Since the {{FlinkKinesisConsumer}} depends only on local information to determine whether or not a new shard due to resharding should be subscribed by a subtask, there is no coordination wrt parent-child shard relationship across subtasks.

Therefore, {{FlinkKinesisConsumer}} does not provide any strong processing ordering guarantees.

Take for example, if initially the assignment is:
Subtask #1 --> Shard A
Subtask #2 --> Shard B

Assume A & B is merged to create shard C, and subtask #1 locally determines that it should be assigned shard C.

Since Flink generally does not provide coordinating facilities between subtask instances, there is no means of coordinating that shard C is consumed only after shard B is also fully consumed.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)