@Override
public void initialize() {
log.debug("Going to initialize required znode structure in zookeeper");
for (NodeType type : NodeType.values()) {
String child = CoordinationUtil.nodeNameOf(type);
rootNode.createChild(znode().withPath(child));
log.debug("Created node {}", child);
}
rootNode.createChild(znode().withPath(CoordinationUtil.STATUSES_NODE_NAME));
log.debug("Created node {}", CoordinationUtil.STATUSES_NODE_NAME);
log.debug("Successfully initialized");
}
private <C extends Command<R>, R extends Serializable> void registerExecutor(
final NodeContext nodeContext, final CommandExecutor<C, R> executor, ZNode node) {
final ZNode executorNode =
node.createChild(znode().withPath(nodeNameOf(executor.getQualifier())));
final ZNode queueNode = executorNode.createChild(znode().withPath("queue"));
executorNode.createChild(znode().withPath("result"));
log.debug("Created znodes for executor {}", executorNode.getPath());
queueNode.addChildrenWatcher(
new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getType() != Event.EventType.NodeChildrenChanged) {
return;
}
synchronized (lock) {
if (log.isDebugEnabled()) {
log.debug(
"Children changed {} event type {}", queueNode.getPath(), event.getType());
}
List<QueueEntry<C, R>> entries = getEntries(queueNode, this);
for (final QueueEntry<C, R> entry : entries) {
Runnable run =
new Runnable() {
@Override
public void run() {
executeCommand(executor, executorNode, entry, nodeContext);
}
};
ZookeeperCoordinator.this.executor.execute(run);
}
}
}
});
}
@Override
public void registerNode(
NodeContext nodeContext, Set<Worker> workers, final StatusChangeListener listener)
throws CoordinatorException {
log.info("Going to register node {} with {} workers", nodeContext.getId(), workers.size());
ZNode typeNode = rootNode.child(CoordinationUtil.nodeNameOf(nodeContext.getId().getType()));
ZNode node = typeNode.createChild(znode().withPath(nodeContext.getId().getIdentifier()));
Set<CommandExecutor<?, ?>> executors = Sets.newHashSet();
Set<Qualifier<?>> qualifiers = Sets.newHashSet();
for (Worker worker : workers) {
for (CommandExecutor<?, ?> executor : worker.getExecutors()) {
Qualifier<?> qualifier = executor.getQualifier();
if (qualifiers.contains(qualifier)) {
throw new CoordinatorException(
"Executor for qualifier " + qualifier + " is already registered");
}
executors.add(executor);
}
}
for (CommandExecutor<?, ?> executor : executors) {
registerExecutor(nodeContext, executor, node);
}
rootNode.addNodeWatcher(
new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getState() == Event.KeeperState.Disconnected) {
listener.onCoordinatorDisconnected();
}
if (event.getState() == Event.KeeperState.SyncConnected) {
listener.onCoordinatorConnected();
}
}
});
ZNode statuses = rootNode.child(CoordinationUtil.STATUSES_NODE_NAME);
statuses.createChild(znode().ephemeralSequential().withDataObject(nodeContext.getId()));
Lock lock = new ReentrantLock();
lock.lock();
try {
Collection<NodeId> nodeIds = Sets.newHashSet();
StatusWatcher statusWatcher = new StatusWatcher(statuses, lock, nodeIds, listener);
List<ZNode> nodes = statuses.children(statusWatcher);
for (ZNode zNode : nodes) {
nodeIds.add(zNode.getObject(NodeId.class));
}
} finally {
lock.unlock();
}
node.createChild(znode().withPath(CoordinationUtil.AVAILABLE_NODE_NAME));
}