[ 
https://issues.apache.org/jira/browse/FLINK-4027?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15333500#comment-15333500
 ] 

ASF GitHub Bot commented on FLINK-4027:
---------------------------------------

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

    https://github.com/apache/flink/pull/2108#discussion_r67318738
  
    --- Diff: 
flink-streaming-connectors/flink-connector-kafka-base/src/main/java/org/apache/flink/streaming/connectors/kafka/FlinkKafkaProducerBase.java
 ---
    @@ -261,7 +298,9 @@ public void invoke(IN next) throws Exception {
                } else {
                        record = new ProducerRecord<>(targetTopic, 
partitioner.partition(next, serializedKey, serializedValue, partitions.length), 
serializedKey, serializedValue);
                }
    -
    +           if(flushOnCheckpoint) {
    --- End diff --
    
    missing space after if


> FlinkKafkaProducer09 sink can lose messages
> -------------------------------------------
>
>                 Key: FLINK-4027
>                 URL: https://issues.apache.org/jira/browse/FLINK-4027
>             Project: Flink
>          Issue Type: Bug
>          Components: Kafka Connector
>    Affects Versions: 1.0.3
>            Reporter: Elias Levy
>            Assignee: Robert Metzger
>            Priority: Critical
>
> The FlinkKafkaProducer09 sink appears to not offer at-least-once guarantees.
> The producer is publishing messages asynchronously.  A callback can record 
> publishing errors, which will be raised when detected.  But as far as I can 
> tell, there is no barrier to wait for async errors from the sink when 
> checkpointing or to track the event time of acked messages to inform the 
> checkpointing process.
> If a checkpoint occurs while there are pending publish requests, and the 
> requests return a failure after the checkpoint occurred, those message will 
> be lost as the checkpoint will consider them processed by the sink.



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

Reply via email to