[
https://issues.apache.org/jira/browse/FLINK-6006?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15904712#comment-15904712
]
ASF GitHub Bot commented on FLINK-6006:
---------------------------------------
GitHub user tzulitai opened a pull request:
https://github.com/apache/flink/pull/3507
[FLINK-6006] [kafka] Always use complete restored state in
FlinkKafkaConsumer
(This PR is the fix of FLINK-6006 for Flink 1.1)
Previously, the Kafka Consumer performs partition list querying on
restore, and then uses it to filter out restored state of partitions
that doesn't exist in the list.
If in any case the returned partitions list is incomplete (i.e. missing
partitions that existed before perhaps due to temporary ZK / broker
downtimes), then the state of the missing partitions is dropped and
cannot be recovered anymore.
This PR fixes this by always restoring the complete state, without
any sort of filtering. We simply let the consumer fail if assigned
partitions to the consuming threads / Kafka clients are unreachable when
the consumer starts running.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/tzulitai/flink FLINK-6006-1.1
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/3507.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #3507
----
commit a57524bfb0158363be9a5bd4a6f18e053d96a030
Author: Tzu-Li (Gordon) Tai <[email protected]>
Date: 2017-03-10T06:47:57Z
[FLINK-6006] [kafka] Always use complete restored state in
FlinkKafkaConsumer
Previously, the Kafka Consumer performs partition list querying on
restore, and then uses it to filter out restored state of partitions
that doesn't exist in the list.
If in any case the returned partitions list is incomplete (i.e. missing
partitions that existed before perhaps due to temporary ZK / broker
downtimes), then the state of the missing partitions is dropped and
cannot be recovered anymore.
This commit fixes this by always restoring the complete state, without
any sort of filtering. We simply let the consumer fail if assigned
partitions to the consuming threads / Kafka clients are unreachable when
the consumer starts running.
----
> Kafka Consumer can lose state if queried partition list is incomplete on
> restore
> --------------------------------------------------------------------------------
>
> Key: FLINK-6006
> URL: https://issues.apache.org/jira/browse/FLINK-6006
> Project: Flink
> Issue Type: Bug
> Components: Kafka Connector, Streaming Connectors
> Reporter: Tzu-Li (Gordon) Tai
> Assignee: Tzu-Li (Gordon) Tai
> Priority: Blocker
> Fix For: 1.1.5, 1.2.1
>
>
> In 1.1.x and 1.2.x, the FlinkKafkaConsumer performs partition list querying
> on restore. Then, only restored state of partitions that exists in the
> queried list is used to initialize the fetcher's state holders.
> If in any case the returned partition list is incomplete (i.e. missing
> partitions that existed before, perhaps due to temporary ZK / broker
> downtime), then the state of the missing partitions is dropped and cannot be
> recovered anymore.
> In 1.3-SNAPSHOT, this is fixed by changes in FLINK-4280, so only 1.1 and 1.2
> is affected.
> We can backport some of the behavioural changes there to 1.1 and 1.2.
> Generally, we should not depend on the current partition list in Kafka when
> restoring, but just restore all previous state into the fetcher's state
> holders.
> This would therefore also require some checking on how the consumer threads /
> Kafka clients behave when its assigned partitions cannot be reached.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
