Till Rohrmann created FLINK-6612:
------------------------------------
Summary: ZooKeeperStateHandleStore does not guard against
concurrent delete operations
Key: FLINK-6612
URL: https://issues.apache.org/jira/browse/FLINK-6612
Project: Flink
Issue Type: Bug
Components: Distributed Coordination, State Backends, Checkpointing
Affects Versions: 1.3.0, 1.4.0
Reporter: Till Rohrmann
Assignee: Till Rohrmann
Priority: Critical
Fix For: 1.3.0, 1.4.0
The {{ZooKeeperStateHandleStore}} does not guard against concurrent delete
operations which could happen in case of a lost leadership and a new leadership
grant. The problem is that checkpoint nodes can get deleted even after they
have been recovered by another {{ZooKeeperCompletedCheckpointStore}}. This
corrupts the recovered checkpoint and thwarts future recoveries.
I propose to add reference counting to the {{ZooKeeperStateHandleStore}}. That
way, we can monitor how many concurrent processes have a hold on a given
checkpoint node. Only if the reference count reaches {{0}}, we are allowed to
delete the checkpoint node and dispose the checkpoint data.
Stephan proposed to use ephemeral child nodes to track the reference count of a
checkpoint node. That way we are sure that locks on the a checkpoint node are
released in case of {{JobManager}} failures.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
