@Override public Set<NodeId> getAvailableNodes(NodeType type) { Set<NodeId> result = Sets.newHashSet(); ZNode typeNode = rootNode.child(CoordinationUtil.nodeNameOf(type)); for (ZNode node : typeNode.children()) { if (node.hasChild(CoordinationUtil.AVAILABLE_NODE_NAME)) { result.add(NodeId.of(type, node.getShortPath())); } } return result; }
@Override public boolean canExecuteCommands(NodeId nodeId, Set<Qualifier<?>> qualifiers) { ZNode typeNode = rootNode.child(CoordinationUtil.nodeNameOf(nodeId.getType())); String identifier = nodeId.getIdentifier(); if (!typeNode.hasChild(identifier)) { throw new CoordinatorException("Node with id " + nodeId + " is not found"); } ZNode node = typeNode.child(identifier); if (!node.hasChild(CoordinationUtil.AVAILABLE_NODE_NAME)) { return false; } for (Qualifier<?> qualifier : qualifiers) { if (!node.hasChild(nodeNameOf(qualifier))) { return false; } } return true; }
private static <C extends Command<R>, R extends Serializable> void executeCommand( CommandExecutor<C, R> executor, ZNode executorNode, final QueueEntry<C, R> entry, final NodeContext nodeContext) { String relativePath = entry.getResultPath().substring(executorNode.getPath().length() + 1); final ZNode output = executorNode.child(relativePath); final NodeCommandExecutionListener<C> listener = entry.getListener(); try { C command = entry.getCommand(); listener.onCommandExecutionStarted(command, nodeContext); R result = executor.execute(command, nodeContext); log.debug("Command {} executed", command); listener.onCommandExecuted(command); output.setObject(CommandExecutionResult.success(result)); } catch (Throwable throwable) { // todo add fail event log.error("error during task execution", throwable); output.setObject(CommandExecutionResult.fail(throwable)); } }
@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)); }