[FLINK-11850][zk] Tolerate concurrent child deletions when deleting owned zNode
When calling ZooKeeperHaServices#closeAndCleanupAllData it can happen that a child of the owned
zNode of the ZooKeeperHaServices is being concurrently deleted (e.g. a LeaderElectionService has
been shut down). In order to tolerate concurrent deletions, we use now ZKPaths#deleteChildren.
This closes #7929.
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/highavailability/zookeeper/ZooKeeperHaServices.java b/flink-runtime/src/main/java/org/apache/flink/runtime/highavailability/zookeeper/ZooKeeperHaServices.java
index 1b2ff44..2596981 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/highavailability/zookeeper/ZooKeeperHaServices.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/highavailability/zookeeper/ZooKeeperHaServices.java
@@ -251,7 +251,21 @@
private void deleteOwnedZNode() throws Exception {
// delete the HA_CLUSTER_ID znode which is owned by this cluster
- client.delete().deletingChildrenIfNeeded().forPath("/");
+
+ // Since we are using Curator version 2.12 there is a bug in deleting the children
+ // if there is a concurrent delete operation. Therefore we need to add this retry
+ // logic. See https://issues.apache.org/jira/browse/CURATOR-430 for more information.
+ // The retry logic can be removed once we upgrade to Curator version >= 4.0.1.
+ boolean zNodeDeleted = false;
+ while (!zNodeDeleted) {
+ try {
+ client.delete().deletingChildrenIfNeeded().forPath("/");
+ zNodeDeleted = true;
+ } catch (KeeperException.NoNodeException ignored) {
+ // concurrent delete operation. Try again.
+ LOG.debug("Retrying to delete owned znode because of other concurrent delete operation.");
+ }
+ }
}
/**
