/**
* Creates or force updates an unassigned node to the OFFLINE state for the specified region.
*
* <p>Attempts to create the node but if it exists will force it to transition to and OFFLINE
* state.
*
* <p>Sets a watcher on the unassigned region node if the method is successful.
*
* <p>This method should be used when assigning a region.
*
* @param zkw zk reference
* @param region region to be created as offline
* @param serverName server event originates from
* @throws KeeperException if unexpected zookeeper exception
* @throws KeeperException.NodeExistsException if node already exists
*/
public static boolean createOrForceNodeOffline(
ZooKeeperWatcher zkw, HRegionInfo region, String serverName) throws KeeperException {
LOG.debug(
zkw.prefix(
"Creating (or updating) unassigned node for "
+ region.getEncodedName()
+ " with OFFLINE state"));
RegionTransitionData data =
new RegionTransitionData(EventType.M_ZK_REGION_OFFLINE, region.getRegionName(), serverName);
synchronized (zkw.getNodes()) {
String node = getNodeName(zkw, region.getEncodedName());
zkw.sync(node);
zkw.getNodes().add(node);
int version = ZKUtil.checkExists(zkw, node);
if (version == -1) {
ZKUtil.createAndWatch(zkw, node, data.getBytes());
} else {
if (!ZKUtil.setData(zkw, node, data.getBytes(), version)) {
return false;
} else {
// We successfully forced to OFFLINE, reset watch and handle if
// the state changed in between our set and the watch
RegionTransitionData curData = ZKAssign.getData(zkw, region.getEncodedName());
if (curData.getEventType() != data.getEventType()) {
// state changed, need to process
return false;
}
}
}
}
return true;
}
public static void createNodeOffline(
ZooKeeperWatcher zkw, HRegionInfo region, String serverName, final EventType event)
throws KeeperException, KeeperException.NodeExistsException {
LOG.debug(
zkw.prefix(
"Creating unassigned node for " + region.getEncodedName() + " in OFFLINE state"));
RegionTransitionData data = new RegionTransitionData(event, region.getRegionName(), serverName);
synchronized (zkw.getNodes()) {
String node = getNodeName(zkw, region.getEncodedName());
zkw.getNodes().add(node);
ZKUtil.createAndWatch(zkw, node, data.getBytes());
}
}
/**
* Creates a new unassigned node in the CLOSING state for the specified region.
*
* <p>Does not transition nodes from any states. If a node already exists for this region, a
* {@link NodeExistsException} will be thrown.
*
* <p>If creation is successful, returns the version number of the CLOSING node created.
*
* <p>Does not set any watches.
*
* <p>This method should only be used by a RegionServer when initiating a close of a region after
* receiving a CLOSE RPC from the Master.
*
* @param zkw zk reference
* @param region region to be created as closing
* @param serverName server event originates from
* @return version of node after transition, -1 if unsuccessful transition
* @throws KeeperException if unexpected zookeeper exception
* @throws KeeperException.NodeExistsException if node already exists
*/
public static int createNodeClosing(ZooKeeperWatcher zkw, HRegionInfo region, String serverName)
throws KeeperException, KeeperException.NodeExistsException {
LOG.debug(
zkw.prefix(
"Creating unassigned node for " + region.getEncodedName() + " in a CLOSING state"));
RegionTransitionData data =
new RegionTransitionData(
EventType.RS_ZK_REGION_CLOSING, region.getRegionName(), serverName);
synchronized (zkw.getNodes()) {
String node = getNodeName(zkw, region.getEncodedName());
zkw.getNodes().add(node);
return ZKUtil.createAndWatch(zkw, node, data.getBytes());
}
}
/**
* Sets the location of <code>hbase:meta</code> in ZooKeeper to the specified server address.
*
* @param zookeeper
* @param serverName
* @param replicaId
* @param state
* @throws KeeperException
*/
public static void setMetaLocation(
ZooKeeperWatcher zookeeper, ServerName serverName, int replicaId, RegionState.State state)
throws KeeperException {
LOG.info("Setting hbase:meta region location in ZooKeeper as " + serverName);
// Make the MetaRegionServer pb and then get its bytes and save this as
// the znode content.
MetaRegionServer pbrsr =
MetaRegionServer.newBuilder()
.setServer(ProtobufUtil.toServerName(serverName))
.setRpcVersion(HConstants.RPC_CURRENT_VERSION)
.setState(state.convert())
.build();
byte[] data = ProtobufUtil.prependPBMagic(pbrsr.toByteArray());
try {
ZKUtil.setData(zookeeper, zookeeper.getZNodeForReplica(replicaId), data);
} catch (KeeperException.NoNodeException nne) {
if (replicaId == HRegionInfo.DEFAULT_REPLICA_ID) {
LOG.debug("META region location doesn't exist, create it");
} else {
LOG.debug("META region location doesn't exist for replicaId " + replicaId + ", create it");
}
ZKUtil.createAndWatch(zookeeper, zookeeper.getZNodeForReplica(replicaId), data);
}
}
