/**
* Gets the current data in the unassigned node for the specified region name or fully-qualified
* path.
*
* <p>Returns null if the region does not currently have a node.
*
* <p>Sets a watch on the node if the node exists.
*
* @param zkw zk reference
* @param pathOrRegionName fully-specified path or region name
* @param stat object to populate the version.
* @return data for the unassigned node
* @throws KeeperException if unexpected zookeeper exception
*/
public static RegionTransitionData getDataAndWatch(
ZooKeeperWatcher zkw, String pathOrRegionName, Stat stat) throws KeeperException {
String node =
pathOrRegionName.startsWith("/") ? pathOrRegionName : getNodeName(zkw, pathOrRegionName);
byte[] data = ZKUtil.getDataAndWatch(zkw, node, stat);
if (data == null) {
return null;
}
return RegionTransitionData.fromBytes(data);
}
/**
* Verifies that the specified region is in the specified state in ZooKeeper.
*
* <p>Returns true if region is in transition and in the specified state in ZooKeeper. Returns
* false if the region does not exist in ZK or is in a different state.
*
* <p>Method synchronizes() with ZK so will yield an up-to-date result but is a slow read.
*
* @param zkw
* @param region
* @param expectedState
* @return true if region exists and is in expected state
*/
public static boolean verifyRegionState(
ZooKeeperWatcher zkw, HRegionInfo region, EventType expectedState) throws KeeperException {
String encoded = region.getEncodedName();
String node = getNodeName(zkw, encoded);
zkw.sync(node);
// Read existing data of the node
byte[] existingBytes = null;
try {
existingBytes = ZKUtil.getDataAndWatch(zkw, node);
} catch (KeeperException.NoNodeException nne) {
return false;
} catch (KeeperException e) {
throw e;
}
if (existingBytes == null) return false;
RegionTransitionData existingData = RegionTransitionData.fromBytes(existingBytes);
if (existingData.getEventType() == expectedState) {
return true;
}
return false;
}
