[ 
https://issues.apache.org/jira/browse/FLUME-2173?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15390761#comment-15390761
 ] 

Chris Horrocks commented on FLUME-2173:
---------------------------------------

I would have assumed that the writing to the sink would be conditional on 
having successfully incremented the offset. Obviously not ideal as is 
eitherway, an upstream source receiving events from multiple sinks would need 
to indepedently track the state of each offset, presenting scalability and 
persistence challenges.

> Exactly once semantics for Flume
> --------------------------------
>
>                 Key: FLUME-2173
>                 URL: https://issues.apache.org/jira/browse/FLUME-2173
>             Project: Flume
>          Issue Type: Bug
>            Reporter: Hari Shreedharan
>            Assignee: Hari Shreedharan
>             Fix For: v2.0.0
>
>
> Currently Flume guarantees only at least once semantics. This jira is meant 
> to track exactly once semantics for Flume. My initial idea is to include uuid 
> event ids on events at the original source (use a config to mark a source an 
> original source) and identify destination sinks. At the destination sinks, 
> use a unique ZK Znode to track the events. If once seen (and configured), 
> pull the duplicate out.
> This might need some refactoring, but my belief is we can do this in a 
> backward compatible way.



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

Reply via email to