[
https://issues.apache.org/jira/browse/FLINK-8516?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16347001#comment-16347001
]
ASF GitHub Bot commented on FLINK-8516:
---------------------------------------
Github user tzulitai commented on a diff in the pull request:
https://github.com/apache/flink/pull/5393#discussion_r165083343
--- Diff:
flink-connectors/flink-connector-kinesis/src/main/java/org/apache/flink/streaming/connectors/kinesis/internals/KinesisDataFetcher.java
---
@@ -584,17 +594,34 @@ private static ShardMetricsReporter
registerShardMetrics(MetricGroup metricGroup
// Miscellaneous utility functions
//
------------------------------------------------------------------------
+ /**
+ * Function to map a Kinesis shard to a Flink subtask index.
+ */
+ public interface ShardToSubtaskIndexFn {
+ /**
+ * Function to map a Kinesis shard to a Flink subtask index.
+ *
+ * @param shard the shard to determine
+ * @param totalNumberOfSubtasks total number of subtasks
+ * @return index or hash code
+ */
+ // TODO: extra parameter can be eliminated by creating hash
function after runtime context is present
+ int getSubTaskIndex(StreamShardHandle shard, int
totalNumberOfSubtasks);
--- End diff --
I actually prefer passing the `totalNumberOfSubtasks` value independently,
instead of passing in `runtimeContext`. IMO, it provides more context on the
nature of the assignment.
Moreover, IMO, having a factory as the API is much more complicating for
the user.
> FlinkKinesisConsumer does not balance shards over subtasks
> ----------------------------------------------------------
>
> Key: FLINK-8516
> URL: https://issues.apache.org/jira/browse/FLINK-8516
> Project: Flink
> Issue Type: Bug
> Components: Kinesis Connector
> Affects Versions: 1.4.0, 1.3.2, 1.5.0
> Reporter: Thomas Weise
> Assignee: Thomas Weise
> Priority: Major
>
> The hash code of the shard is used to distribute discovered shards over
> subtasks round robin. This works as long as shard identifiers are sequential.
> After shards are rebalanced in Kinesis, that may no longer be the case and
> the distribution become skewed.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
