public void addChildWatcher(String path) throws Exception {
// path=/webServiceCenter/userCenter/tc.dd.test.do
// 对path下的子节点进行监控,即就是对ip监控
final PathChildrenCache cache = new PathChildrenCache(this.client, path, true);
cache.start(StartMode.POST_INITIALIZED_EVENT); // ppt中需要讲StartMode
// System.out.println(cache.getCurrentData().size());
cache
.getListenable()
.addListener(
new PathChildrenCacheListener() {
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
throws Exception {
if (event.getType().equals(PathChildrenCacheEvent.Type.INITIALIZED)) {
System.out.println("客户端子节点cache初始化数据完成");
// System.out.println("size="+cache.getCurrentData().size());
} else if (event.getType().equals(PathChildrenCacheEvent.Type.CHILD_ADDED)) {
// System.out.println("添加子节点:"+event.getData().getPath());
// System.out.println("修改子节点数据:"+new String(event.getData().getData()));
updateLocalService(event.getData().getPath(), 0);
} else if (event.getType().equals(PathChildrenCacheEvent.Type.CHILD_REMOVED)) {
System.out.println("删除子节点:" + event.getData().getPath());
// if(services.containsKey(event.getData().getPath()))
// servicesByP.containsKey(event.getData().)
updateLocalService(event.getData().getPath(), 1);
} else if (event.getType().equals(PathChildrenCacheEvent.Type.CHILD_UPDATED)) {
// System.out.println("修改子节点数据:"+event.getData().getPath());
// System.out.println("修改子节点数据:"+new String(event.getData().getData()));
}
}
});
}
private static void list(PathChildrenCache cache) {
if (cache.getCurrentData().size() == 0) {
System.out.println("* empty *");
} else {
for (ChildData data : cache.getCurrentData()) {
System.out.println(data.getPath() + " = " + new String(data.getData()));
}
}
}
private static void addListener(PathChildrenCache cache) {
// a PathChildrenCacheListener is optional. Here, it's used just to log changes
PathChildrenCacheListener listener =
new PathChildrenCacheListener() {
@Override
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
throws Exception {
switch (event.getType()) {
case CHILD_ADDED:
{
System.out.println(
"Node added: " + ZKPaths.getNodeFromPath(event.getData().getPath()));
break;
}
case CHILD_UPDATED:
{
System.out.println(
"Node changed: " + ZKPaths.getNodeFromPath(event.getData().getPath()));
break;
}
case CHILD_REMOVED:
{
System.out.println(
"Node removed: " + ZKPaths.getNodeFromPath(event.getData().getPath()));
break;
}
}
}
};
cache.getListenable().addListener(listener);
}
/**
* Construct a ChildPathIterator.
*
* @param converter converter from node data to domain object
* @param cache source for children nodes
*/
public ChildPathIterator(Converter<ChildData, T> converter, PathChildrenCache cache) {
Assert.notNull(converter);
Assert.notNull(cache);
this.converter = converter;
List<ChildData> list = cache.getCurrentData();
this.iterator = list == null ? Collections.<ChildData>emptyIterator() : list.iterator();
}
public static void main(String[] args) throws Exception {
CuratorFramework client = null;
PathChildrenCache cache = null;
try {
client =
CuratorFrameworkFactory.newClient("localhost:2181", new ExponentialBackoffRetry(1000, 3));
client.start();
// in this example we will cache data. Notice that this is optional.
cache = new PathChildrenCache(client, PATH, true);
cache.start();
processCommands(client, cache);
} finally {
Closeables.closeQuietly(cache);
Closeables.closeQuietly(client);
}
}
/**
* 监听某个节点下的直接一级节点 孩子节点的创建，删除，更新
*
* @throws Exception
*/
@Test
public void testWatcherPath() throws Exception {
// 2.Register watcher
PathChildrenCache watcher =
new PathChildrenCache(
client, ZK_PATH, true // if cache data
);
watcher
.getListenable()
.addListener(
new PathChildrenCacheListener() {
@Override
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
throws Exception {
ChildData data = event.getData();
if (data == null) {
System.out.println("No data in event[" + event + "]");
} else {
System.out.println(
"Receive event: "
+ "type=["
+ event.getType()
+ "]"
+ ", path=["
+ data.getPath()
+ "]"
+ ", data=["
+ new String(data.getData())
+ "]"
+ ", stat=["
+ data.getStat()
+ "]");
}
}
});
watcher.start(PathChildrenCache.StartMode.BUILD_INITIAL_CACHE);
System.out.println("Register zk watcher successfully!");
Thread.sleep(Integer.MAX_VALUE);
}
@LifecycleStop
public void stop() {
log.info("Stopping ZkCoordinator for [%s]", me);
synchronized (lock) {
if (!started) {
return;
}
try {
loadQueueCache.close();
} catch (Exception e) {
throw Throwables.propagate(e);
} finally {
loadQueueCache = null;
started = false;
}
}
}
@LifecycleStart
public void start() throws IOException {
synchronized (lock) {
if (started) {
return;
}
log.info("Starting zkCoordinator for server[%s]", me.getName());
final String loadQueueLocation = ZKPaths.makePath(zkPaths.getLoadQueuePath(), me.getName());
final String servedSegmentsLocation =
ZKPaths.makePath(zkPaths.getServedSegmentsPath(), me.getName());
final String liveSegmentsLocation =
ZKPaths.makePath(zkPaths.getLiveSegmentsPath(), me.getName());
loadQueueCache = new PathChildrenCache(curator, loadQueueLocation, true, true, loadingExec);
try {
curator.newNamespaceAwareEnsurePath(loadQueueLocation).ensure(curator.getZookeeperClient());
curator
.newNamespaceAwareEnsurePath(servedSegmentsLocation)
.ensure(curator.getZookeeperClient());
curator
.newNamespaceAwareEnsurePath(liveSegmentsLocation)
.ensure(curator.getZookeeperClient());
loadLocalCache();
loadQueueCache
.getListenable()
.addListener(
new PathChildrenCacheListener() {
@Override
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
throws Exception {
final ChildData child = event.getData();
switch (event.getType()) {
case CHILD_ADDED:
final String path = child.getPath();
final DataSegmentChangeRequest request =
jsonMapper.readValue(child.getData(), DataSegmentChangeRequest.class);
log.info("New request[%s] with zNode[%s].", request.asString(), path);
try {
request.go(
getDataSegmentChangeHandler(),
new DataSegmentChangeCallback() {
boolean hasRun = false;
@Override
public void execute() {
try {
if (!hasRun) {
curator.delete().guaranteed().forPath(path);
log.info("Completed request [%s]", request.asString());
hasRun = true;
}
} catch (Exception e) {
try {
curator.delete().guaranteed().forPath(path);
} catch (Exception e1) {
log.error(
e1,
"Failed to delete zNode[%s], but ignoring exception.",
path);
}
log.error(e, "Exception while removing zNode[%s]", path);
throw Throwables.propagate(e);
}
}
});
} catch (Exception e) {
try {
curator.delete().guaranteed().forPath(path);
} catch (Exception e1) {
log.error(
e1, "Failed to delete zNode[%s], but ignoring exception.", path);
}
log.makeAlert(e, "Segment load/unload: uncaught exception.")
.addData("node", path)
.addData("nodeProperties", request)
.emit();
}
break;
case CHILD_REMOVED:
log.info("zNode[%s] was removed", event.getData().getPath());
break;
default:
log.info("Ignoring event[%s]", event);
}
}
});
loadQueueCache.start();
} catch (Exception e) {
Throwables.propagateIfPossible(e, IOException.class);
throw Throwables.propagate(e);
}
started = true;
}
}
@LifecycleStart
public void start() throws IOException {
log.info("Starting zkCoordinator for server[%s]", me);
synchronized (lock) {
if (started) {
return;
}
final String loadQueueLocation = ZKPaths.makePath(zkPaths.getLoadQueuePath(), me.getName());
final String servedSegmentsLocation =
ZKPaths.makePath(zkPaths.getServedSegmentsPath(), me.getName());
final String liveSegmentsLocation =
ZKPaths.makePath(zkPaths.getLiveSegmentsPath(), me.getName());
loadQueueCache =
new PathChildrenCache(
curator,
loadQueueLocation,
true,
true,
new ThreadFactoryBuilder().setDaemon(true).setNameFormat("ZkCoordinator-%s").build());
try {
config.getInfoDir().mkdirs();
curator.newNamespaceAwareEnsurePath(loadQueueLocation).ensure(curator.getZookeeperClient());
curator
.newNamespaceAwareEnsurePath(servedSegmentsLocation)
.ensure(curator.getZookeeperClient());
curator
.newNamespaceAwareEnsurePath(liveSegmentsLocation)
.ensure(curator.getZookeeperClient());
loadCache();
loadQueueCache
.getListenable()
.addListener(
new PathChildrenCacheListener() {
@Override
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
throws Exception {
final ChildData child = event.getData();
switch (event.getType()) {
case CHILD_ADDED:
final String path = child.getPath();
final DataSegmentChangeRequest segment =
jsonMapper.readValue(child.getData(), DataSegmentChangeRequest.class);
log.info("New node[%s] with segmentClass[%s]", path, segment.getClass());
try {
segment.go(ZkCoordinator.this);
curator.delete().guaranteed().forPath(path);
log.info("Completed processing for node[%s]", path);
} catch (Exception e) {
try {
curator.delete().guaranteed().forPath(path);
} catch (Exception e1) {
log.info(
e1, "Failed to delete node[%s], but ignoring exception.", path);
}
log.makeAlert(e, "Segment load/unload: uncaught exception.")
.addData("node", path)
.addData("nodeProperties", segment)
.emit();
}
break;
case CHILD_REMOVED:
log.info("%s was removed", event.getData().getPath());
break;
default:
log.info("Ignoring event[%s]", event);
}
}
});
loadQueueCache.start();
} catch (Exception e) {
Throwables.propagateIfPossible(e, IOException.class);
throw Throwables.propagate(e);
}
started = true;
}
}