[ 
https://issues.apache.org/jira/browse/TWILL-199?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15799233#comment-15799233
 ] 

ASF GitHub Bot commented on TWILL-199:
--------------------------------------

Github user maochf commented on a diff in the pull request:

    https://github.com/apache/twill/pull/16#discussion_r94658662
  
    --- Diff: 
twill-api/src/main/java/org/apache/twill/api/ServiceAnnouncer.java ---
    @@ -32,7 +32,7 @@
       Cancellable announce(String serviceName, int port);
     
       /**
    -   * Registers an endpoint that could be discovered by external party with 
a payload
    +   * Registers an endpoint that could be discovered by external party with 
a payload.
    --- End diff --
    
    checkstyle fix


> Get next offset and handle offset error in KafkaConsumer.MessageCallback
> ------------------------------------------------------------------------
>
>                 Key: TWILL-199
>                 URL: https://issues.apache.org/jira/browse/TWILL-199
>             Project: Apache Twill
>          Issue Type: Improvement
>            Reporter: Chengfeng Mao
>
> The method {{void onReceived(Iterator<FetchedMessage> messages)}} in 
> {{KafkaConsumer.MessageCallback}} can be more flexible with the change to 
> {{Long onReceived(Iterator<FetchedMessage> messages)}} so that it can provide 
> additional functionalities:
> 1. To return the next offset to be fetched
> 2. To handle offset non-existence or offset mismatch error and take action on 
> the error
> This method will return null for backward compatibility when it doesn't need 
> to provide the next offset.
> In concrete implementation,  a class of a new interface 
> {{KafkaOffsetProvider}} can be added as a member in 
> {{KafkaConsumer.MessageCallback}} to perform the offset error handling and 
> provide the next offset. Besides, {{KafkaOffsetProvider}} also has methods to 
> provide the following functionalities:
> 1. To fetch earliest/latest offset in Kafka
> 2. To find the offset of a message with timestamp equal to the given 
> timestamp in Kafka
> For backward compatibility, if {{KafkaOffsetProvider}} instance is not 
> provided, its default value will be null and none of its methods will be 
> called.



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

Reply via email to