[
https://issues.apache.org/jira/browse/KAFKA-6092?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16211734#comment-16211734
]
Stephane Maarek commented on KAFKA-6092:
----------------------------------------
or maybe it's just a matter of enhancing the documentation
> Time passed in punctuate call is currentTime, not punctuate schedule time.
> ---------------------------------------------------------------------------
>
> Key: KAFKA-6092
> URL: https://issues.apache.org/jira/browse/KAFKA-6092
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 0.11.0.0
> Reporter: Stephane Maarek
>
> The java doc specifies that for a Transformer, calling context.schedule calls
> punctuate every 1000ms. This is not entirely accurate, as if no data is
> received for a while, punctuate won't be called.
> {code}
> * void init(ProcessorContext context) {
> * this.context = context;
> * this.state = context.getStateStore("myTransformState");
> * context.schedule(1000); // call #punctuate() each
> 1000ms
> * }
> {code}
> When you receive new data say after 20 seconds, punctuate will play catch up
> and will be called 20 times at reception of the new data.
> the signature of punctuate is
> {code}
> * KeyValue punctuate(long timestamp) {
> * // can access this.state
> * // can emit as many new KeyValue pairs as required via
> this.context#forward()
> * return null; // don't return result -- can also be
> "new KeyValue()"
> * }
> {code}
> but the timestamp being passed is currentTimestamp at the time of the call to
> punctuate, not at the time the punctuate was scheduled. It is very confusing
> and I think the timestamp should represent the one at which the punctuate
> should have been scheduled. Getting the current timestamp is not adding much
> information as it can easily obtained using System.currentTimeMillis();
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
