[ 
https://issues.apache.org/jira/browse/KAFKA-2217?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jason Gustafson updated KAFKA-2217:
-----------------------------------
    Attachment: KAFKA-2217_2015-05-26_09:37:29.patch

> Refactor Client Selectable Interface for Better Concurrency Options
> -------------------------------------------------------------------
>
>                 Key: KAFKA-2217
>                 URL: https://issues.apache.org/jira/browse/KAFKA-2217
>             Project: Kafka
>          Issue Type: Improvement
>            Reporter: Jason Gustafson
>            Assignee: Jason Gustafson
>         Attachments: KAFKA-2217.patch, KAFKA-2217_2015-05-25_10:45:30.patch, 
> KAFKA-2217_2015-05-26_09:37:29.patch
>
>
> The current Selectable interface makes thread-safe usage without external 
> locking unlikely. In particular, the interface requires implementations to 
> store internal lists containing the results from an invocation of poll. This 
> makes dealing with issues such as KAFKA-2168 more difficult since it adds 
> state which must be synchronized. Here are the offending methods:
> {code:java}
> interface Selectable {
>   void poll(long timeout);
>   List<NetworkSend> completedSends();
>   List<NetworkReceive> completedReceives();
>   List<Integer> disconnected();
>   List<Integer> connected();
>   // rest excluded
> }
> {code}
> The user is required to invoke poll, then extract the results from the 
> corresponding methods. In order to avoid missing events, the caller must hold 
> an external lock while they access the results of the poll. 
> Instead, we can return the results directly from poll call using a container 
> class. For example:
> {code:java}
> class PollResult {
>   List<NetworkSend> completedSends;
>   List<NetworkReceive> completedReceives;
>   List<Integer> disconnected;
>   List<Integer> connected;
> }
> interface Selectable {
>   PollResult poll(long timeout);
> }
> {code}
> This should get us closer to a thread-safe NetworkClient, which would enable 
> a more granular approach to synchronizing the KafkaConsumer.



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

Reply via email to