[ 
https://issues.apache.org/jira/browse/KAFKA-4322?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15708790#comment-15708790
 ] 

Eno Thereska commented on KAFKA-4322:
-------------------------------------

[~markshelton] We tend not to have such callbacks in streams. Would a listener 
word, e.g., you can register a listener and it's called upon restore completion 
(with number of records restored). That way we can get rid of the start restore 
callback. We have a PR open that adds listeners for monitoring the state an 
instance is at (https://github.com/apache/kafka/pull/2135). You can see how the 
listeners work there. 

> StateRestoreCallback begin and end indication
> ---------------------------------------------
>
>                 Key: KAFKA-4322
>                 URL: https://issues.apache.org/jira/browse/KAFKA-4322
>             Project: Kafka
>          Issue Type: Improvement
>          Components: streams
>    Affects Versions: 0.10.1.0
>            Reporter: Mark Shelton
>            Assignee: Mark Shelton
>            Priority: Minor
>
> In Kafka Streams, the StateRestoreCallback interface provides only a single 
> method "restore(byte[] key, byte[] value)" that is called for every key-value 
> pair to be restored. 
> It would be nice to have "beginRestore" and "endRestore" methods as part of 
> StateRestoreCallback.
> Kafka Streams would call "beginRestore" before restoring any keys, and would 
> call "endRestore" when it determines that it is done. This allows an 
> implementation, for example, to report on the number of keys restored and 
> perform a commit after the last key was restored. Other uses are conceivable.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to