/**
* Deletes an existing unassigned node that is in the specified state for the specified region.
*
* <p>If a node does not already exist for this region, a {@link NoNodeException} will be thrown.
*
* <p>No watcher is set whether this succeeds or not.
*
* <p>Returns false if the node was not in the proper state but did exist.
*
* <p>This method is used during table disables when a region finishes successfully closing. This
* is the Master acknowledging completion of the specified regions transition to being closed.
*
* @param zkw zk reference
* @param regionName region to be deleted from zk
* @param expectedState state region must be in for delete to complete
* @param expectedVersion of the znode that is to be deleted. If expectedVersion need not be
* compared while deleting the znode pass -1
* @throws KeeperException if unexpected zookeeper exception
* @throws KeeperException.NoNodeException if node does not exist
*/
public static boolean deleteNode(
ZooKeeperWatcher zkw, String regionName, EventType expectedState, int expectedVersion)
throws KeeperException, KeeperException.NoNodeException {
LOG.debug(
zkw.prefix(
"Deleting existing unassigned "
+ "node for "
+ regionName
+ " that is in expected state "
+ expectedState));
String node = getNodeName(zkw, regionName);
zkw.sync(node);
Stat stat = new Stat();
byte[] bytes = ZKUtil.getDataNoWatch(zkw, node, stat);
if (bytes == null) {
// If it came back null, node does not exist.
throw KeeperException.create(Code.NONODE);
}
RegionTransitionData data = RegionTransitionData.fromBytes(bytes);
if (!data.getEventType().equals(expectedState)) {
LOG.warn(
zkw.prefix(
"Attempting to delete unassigned "
+ "node "
+ regionName
+ " in "
+ expectedState
+ " state but node is in "
+ data.getEventType()
+ " state"));
return false;
}
if (expectedVersion != -1 && stat.getVersion() != expectedVersion) {
LOG.warn(
"The node we are trying to delete is not the expected one. " + "Got a version mismatch");
return false;
}
synchronized (zkw.getNodes()) {
// TODO: Does this go here or only if we successfully delete node?
zkw.getNodes().remove(node);
if (!ZKUtil.deleteNode(zkw, node, stat.getVersion())) {
LOG.warn(
zkw.prefix(
"Attempting to delete "
+ "unassigned node in "
+ expectedState
+ " state but "
+ "after verifying it was in OPENED state, we got a version mismatch"));
return false;
}
LOG.debug(
zkw.prefix(
"Successfully deleted unassigned node for region "
+ regionName
+ " in expected state "
+ expectedState));
return true;
}
}
public void deleteMetaLocation(ZooKeeperWatcher zookeeper, int replicaId) throws KeeperException {
if (replicaId == HRegionInfo.DEFAULT_REPLICA_ID) {
LOG.info("Deleting hbase:meta region location in ZooKeeper");
} else {
LOG.info("Deleting hbase:meta for " + replicaId + " region location in ZooKeeper");
}
try {
// Just delete the node. Don't need any watches.
ZKUtil.deleteNode(zookeeper, zookeeper.getZNodeForReplica(replicaId));
} catch (KeeperException.NoNodeException nne) {
// Has already been deleted
}
}
