/**
* Helper method to connect to a peer
*
* @param peerId peer's identifier
* @return object representing the peer
* @throws ReplicationException
*/
private ReplicationPeer getPeer(String peerId) throws ReplicationException {
Configuration peerConf = getPeerConf(peerId);
if (peerConf == null) {
return null;
}
if (this.ourClusterKey.equals(ZKUtil.getZooKeeperClusterKey(peerConf))) {
LOG.debug("Not connecting to " + peerId + " because it's us");
return null;
}
ReplicationPeer peer =
new ReplicationPeer(peerConf, peerId, ZKUtil.getZooKeeperClusterKey(peerConf));
try {
peer.startStateTracker(this.zookeeper, this.getPeerStateNode(peerId));
} catch (KeeperException e) {
throw new ReplicationException(
"Error starting the peer state tracker for peerId=" + peerId, e);
}
try {
peer.startTableCFsTracker(this.zookeeper, this.getTableCFsNode(peerId));
} catch (KeeperException e) {
throw new ReplicationException(
"Error starting the peer tableCFs tracker for peerId=" + peerId, e);
}
peer.getZkw().registerListener(new PeerRegionServerListener(peer));
return peer;
}
@Override
public void disconnectFromPeer(String peerId) {
ReplicationPeer rp = this.peerClusters.get(peerId);
if (rp != null) {
rp.getZkw().close();
this.peerClusters.remove(peerId);
}
}
/**
* Returns all region servers from given peer
*
* @param peerClusterId (byte) the cluster to interrogate
* @return addresses of all region servers
*/
public List<HServerAddress> getSlavesAddresses(String peerClusterId) {
if (this.peerClusters.size() == 0) {
return new ArrayList<HServerAddress>(0);
}
ReplicationPeer peer = this.peerClusters.get(peerClusterId);
if (peer == null) {
return new ArrayList<HServerAddress>(0);
}
peer.setRegionServers(fetchSlavesAddresses(peer.getZkw()));
return peer.getRegionServers();
}
@Override
public synchronized void nodeChildrenChanged(String path) {
if (path.equals(regionServerListNode)) {
try {
LOG.info("Detected change to peer regionservers, fetching updated list");
peer.setRegionServers(fetchSlavesAddresses(peer.getZkw()));
} catch (KeeperException e) {
LOG.fatal("Error reading slave addresses", e);
}
}
}
/**
* A private method used to re-establish a zookeeper session with a peer cluster.
*
* @param ke
* @param peer
*/
private void reconnectPeer(KeeperException ke, ReplicationPeer peer) {
if (ke instanceof ConnectionLossException
|| ke instanceof SessionExpiredException
|| ke instanceof AuthFailedException) {
LOG.warn("Lost the ZooKeeper connection for peer " + peer.getClusterKey(), ke);
try {
peer.reloadZkWatcher();
peer.getZkw().registerListener(new PeerRegionServerListener(peer));
} catch (IOException io) {
LOG.warn("Creation of ZookeeperWatcher failed for peer " + peer.getClusterKey(), io);
}
}
}
@Override
public UUID getPeerUUID(String peerId) {
ReplicationPeer peer = this.peerClusters.get(peerId);
if (peer == null) {
return null;
}
UUID peerUUID = null;
try {
peerUUID = ZKClusterId.getUUIDForCluster(peer.getZkw());
} catch (KeeperException ke) {
reconnectPeer(ke, peer);
}
return peerUUID;
}
/**
* This method connects this cluster to another one and registers it in this region server's
* replication znode
*
* @param peerId id of the peer cluster
*/
public boolean connectToPeer(String peerId) throws IOException {
if (this.clientOnly) {
return false;
}
if (this.peerClusters.containsKey(peerId)) {
return false;
// TODO remove when we support it
} else if (this.peerClusters.size() > 0) {
LOG.warn("Multiple slaves feature not supported");
return false;
}
ReplicationPeer peer = getPeer(peerId);
if (peer == null) {
return false;
}
this.peerClusters.put(peerId, peer);
this.zookeeperWrapper.ensureExists(
this.zookeeperWrapper.getZNode(this.rsServerNameZnode, peerId));
LOG.info("Added new peer cluster " + peer.getClusterKey());
return true;
}
@Override
public boolean connectToPeer(String peerId) throws ReplicationException {
if (peerClusters == null) {
return false;
}
if (this.peerClusters.containsKey(peerId)) {
return false;
}
ReplicationPeer peer = null;
try {
peer = getPeer(peerId);
} catch (Exception e) {
throw new ReplicationException("Error connecting to peer with id=" + peerId, e);
}
if (peer == null) {
return false;
}
this.peerClusters.put(peerId, peer);
LOG.info("Added new peer cluster " + peer.getClusterKey());
return true;
}
@Override
public List<ServerName> getRegionServersOfConnectedPeer(String peerId) {
if (this.peerClusters.size() == 0) {
return Collections.emptyList();
}
ReplicationPeer peer = this.peerClusters.get(peerId);
if (peer == null) {
return Collections.emptyList();
}
List<ServerName> addresses;
try {
addresses = fetchSlavesAddresses(peer.getZkw());
} catch (KeeperException ke) {
if (LOG.isDebugEnabled()) {
LOG.debug("Fetch salves addresses failed.", ke);
}
reconnectPeer(ke, peer);
addresses = Collections.emptyList();
}
peer.setRegionServers(addresses);
return peer.getRegionServers();
}
@Override
public boolean getStatusOfPeerFromBackingStore(String id) throws ReplicationException {
try {
if (!peerExists(id)) {
throw new IllegalArgumentException("peer " + id + " doesn't exist");
}
String peerStateZNode = getPeerStateNode(id);
try {
return ReplicationPeer.isStateEnabled(ZKUtil.getData(this.zookeeper, peerStateZNode));
} catch (KeeperException e) {
throw new ReplicationException(e);
} catch (DeserializationException e) {
throw new ReplicationException(e);
}
} catch (KeeperException e) {
throw new ReplicationException(
"Unable to get status of the peer with id=" + id + " from backing store", e);
}
}
public PeerRegionServerListener(ReplicationPeer replicationPeer) {
super(replicationPeer.getZkw());
this.peer = replicationPeer;
this.regionServerListNode = peer.getZkw().rsZNode;
}
