You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@flink.apache.org by tillrohrmann <gi...@git.apache.org> on 2017/05/18 12:08:33 UTC
[GitHub] flink pull request #3940: [backport 1.3] [FLINK-6612] Allow ZooKeeperStateHa...
GitHub user tillrohrmann opened a pull request:
https://github.com/apache/flink/pull/3940
[backport 1.3] [FLINK-6612] Allow ZooKeeperStateHandleStore to lock created ZNodes
Backport of #3939 onto the `release-1.3` branch.
In order to guard against deletions of ZooKeeper nodes which are still being used
by a different ZooKeeperStateHandleStore, we have to introduce a locking mechanism.
Only after all ZooKeeperStateHandleStores have released their lock, the ZNode is
allowed to be deleted.
THe locking mechanism is implemented via ephemeral child nodes of the respective
ZooKeeper node. Whenever a ZooKeeperStateHandleStore wants to lock a ZNode, thus,
protecting it from being deleted, it creates an ephemeral child node. The node's
name is unique to the ZooKeeperStateHandleStore instance. The delete operations
will then only delete the node if it does not have any children associated.
In order to guard against oprhaned lock nodes, they are created as ephemeral nodes.
This means that they will be deleted by ZooKeeper once the connection of the
ZooKeeper client which created the node timed out.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/tillrohrmann/flink addZooKeeperRefCountingBackport
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/3940.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 #3940
----
commit ccb3ac8f2b64a357275d2967fcd440947becd272
Author: Till Rohrmann <tr...@apache.org>
Date: 2017-05-17T12:52:04Z
[FLINK-6612] Allow ZooKeeperStateHandleStore to lock created ZNodes
In order to guard against deletions of ZooKeeper nodes which are still being used
by a different ZooKeeperStateHandleStore, we have to introduce a locking mechanism.
Only after all ZooKeeperStateHandleStores have released their lock, the ZNode is
allowed to be deleted.
THe locking mechanism is implemented via ephemeral child nodes of the respective
ZooKeeper node. Whenever a ZooKeeperStateHandleStore wants to lock a ZNode, thus,
protecting it from being deleted, it creates an ephemeral child node. The node's
name is unique to the ZooKeeperStateHandleStore instance. The delete operations
will then only delete the node if it does not have any children associated.
In order to guard against oprhaned lock nodes, they are created as ephemeral nodes.
This means that they will be deleted by ZooKeeper once the connection of the
ZooKeeper client which created the node timed out.
----
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---
[GitHub] flink issue #3940: [backport 1.3] [FLINK-6612] Allow ZooKeeperStateHandleSto...
Posted by tillrohrmann <gi...@git.apache.org>.
Github user tillrohrmann commented on the issue:
https://github.com/apache/flink/pull/3940
Merged in f58fec70fef12056bd58b6cc2985532ccb07625e
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---
[GitHub] flink pull request #3940: [backport 1.3] [FLINK-6612] Allow ZooKeeperStateHa...
Posted by tillrohrmann <gi...@git.apache.org>.
Github user tillrohrmann closed the pull request at:
https://github.com/apache/flink/pull/3940
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---