org.apache.zookeeper.test.system.InstanceContainer Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.zookeeper.test.system;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.zookeeper.server.ExitCode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.zookeeper.AsyncCallback;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.KeeperException.ConnectionLossException;
import org.apache.zookeeper.KeeperException.NoNodeException;
import org.apache.zookeeper.KeeperException.NodeExistsException;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.test.system.Instance.Reporter;
/**
* This class starts up,
*/
public class InstanceContainer implements Watcher, AsyncCallback.ChildrenCallback {
private final class MyWatcher implements Watcher {
String myNode;
DataCallback dc;
MyWatcher(String myNode, DataCallback dc) {
this.myNode = myNode;
this.dc = dc;
}
public void process(WatchedEvent event) {
if (event.getPath() != null && event.getPath().equals(myNode)) {
zk.getData(myNode, this, dc, this);
}
}
}
private final class MyDataCallback implements DataCallback {
int lastVer;
String myNode;
Instance myInstance;
MyDataCallback(String myNode, Instance myInstance, int ver) {
this.myNode = myNode;
this.myInstance = myInstance;
lastVer = ver;
}
public void processResult(int rc, String path,
Object ctx, byte[] data, Stat stat) {
if (rc == KeeperException.Code.NONODE.intValue()) {
// we can just ignore because the child watcher takes care of this
return;
}
if (rc != KeeperException.Code.OK.intValue()) {
zk.getData(myNode, (Watcher)ctx, this, ctx);
}
int currVer = stat.getVersion();
if (currVer != lastVer) {
String parts[] = new String(data).split(" ", 2);
myInstance.configure(parts[1]);
lastVer = currVer;
}
}
}
private final class MyReporter implements Reporter {
String myReportNode;
public MyReporter(String child) {
myReportNode = reportsNode + '/' + child;
}
public void report(String report) throws KeeperException, InterruptedException {
for(int j = 0; j < maxTries; j++) {
try {
try {
zk.setData(myReportNode, report.getBytes(), -1);
} catch(NoNodeException e) {
zk.create(myReportNode, report.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
}
break;
} catch(ConnectionLossException e) {}
}
}
}
private static final Logger LOG = LoggerFactory.getLogger(InstanceContainer.class);
String name;
String zkHostPort;
// We only run if the readyNode exists
String prefixNode;
String statusNode = "available";
String reportsNode = "reports";
String assignmentsNode = "assignments";
ZooKeeper zk;
static final int sessTimeout = 5000;
static final int maxTries = 3;
public InstanceContainer(String name, String zkHostPort, String prefix) throws UnknownHostException {
if (name.length() == 0 || name.equals("hostname")) {
name = InetAddress.getLocalHost().getCanonicalHostName();
}
this.name = name;
this.zkHostPort = zkHostPort;
this.prefixNode = prefix;
this.statusNode = prefix + '/' + this.statusNode + '/' + name;
this.reportsNode = prefix + '/' + this.reportsNode;
this.assignmentsNode = prefix + '/' + this.assignmentsNode + '/' + name;
}
private void rmnod(String path) throws InterruptedException, KeeperException {
KeeperException lastException = null;
for(int i = 0; i < maxTries; i++) {
try {
zk.delete(path, -1);
lastException = null;
break;
} catch (KeeperException.NoNodeException e) {
// cool this is what we want
break;
} catch (KeeperException e) {
lastException = e;
}
}
if (lastException != null) {
throw lastException;
}
}
private void mknod_inner(String path, CreateMode mode) throws KeeperException, InterruptedException {
for(int i = 0; i < maxTries; i++) {
try {
zk.create(path, null, Ids.OPEN_ACL_UNSAFE, mode);
break;
} catch (NodeExistsException e) {
if (mode != CreateMode.EPHEMERAL) {
return;
}
Stat stat = zk.exists(path, false);
if (stat == null) {
continue;
}
if (stat.getEphemeralOwner() != zk.getSessionId()) {
throw e;
}
break;
} catch (ConnectionLossException e) {
e.printStackTrace();
}
}
}
private void mknod(String path, CreateMode mode) throws KeeperException, InterruptedException {
String subpath[] = path.split("/");
StringBuilder sb = new StringBuilder();
// We start at 1 because / will create an empty part first
for(int i = 1; i < subpath.length; i++) {
sb.append("/");
sb.append(subpath[i]);
CreateMode m = CreateMode.PERSISTENT;
if (i == subpath.length-1) {
m = mode;
}
mknod_inner(sb.toString(), m);
}
}
public void run() throws IOException, InterruptedException, KeeperException {
zk = new ZooKeeper(zkHostPort, sessTimeout, this);
mknod(assignmentsNode, CreateMode.PERSISTENT);
mknod(statusNode, CreateMode.EPHEMERAL);
mknod(reportsNode, CreateMode.PERSISTENT);
// Now we just start watching the assignments directory
zk.getChildren(assignmentsNode, true, this, null);
}
/**
* @param args the first parameter is the instance name, the second
* is the ZooKeeper spec. if the instance name is the empty string
* or "hostname", the hostname will be used.
* @throws InterruptedException
* @throws IOException
* @throws UnknownHostException
* @throws KeeperException
*/
public static void main(String[] args) throws UnknownHostException, IOException, InterruptedException, KeeperException {
if (args.length != 3) {
System.err.println("USAGE: " + InstanceContainer.class.getName() + " name zkHostPort znodePrefix");
System.exit(ExitCode.INVALID_INVOCATION.getValue());
}
new InstanceContainer(args[0], args[1], args[2]).run();
while(true) {
Thread.sleep(1000);
}
}
public void process(WatchedEvent event) {
if (KeeperState.Expired == event.getState()) {
// It's all over
LOG.error("Lost session");
System.exit(ExitCode.ERROR_STARTING_ADMIN_SERVER.getValue());
}
if (event.getPath() != null && event.getPath().equals(assignmentsNode)) {
// children have changed, so read in the new list
zk.getChildren(assignmentsNode, true, this, null);
}
}
Map instances = new HashMap();
@Override
public void processResult(int rc, String path, Object ctx, List children) {
if (rc != KeeperException.Code.OK.intValue()) {
// try it again
zk.getChildren(assignmentsNode, true, this, null);
return;
}
Map newList = new HashMap();
// check for differences
Stat stat = new Stat();
for(String child: children) {
Instance i = instances.remove(child);
if (i == null) {
// Start up a new instance
byte[] data = null;
String myNode = assignmentsNode + '/' + child;
while(true) {
try {
data = zk.getData(myNode, true, stat);
break;
} catch (NoNodeException e) {
// The node doesn't exist anymore, so skip it
break;
} catch (KeeperException e) {
e.printStackTrace();
} catch (InterruptedException e) {
return;
}
}
if (data != null) {
String instanceSpec = new String(data);
int spaceIndex = instanceSpec.indexOf(' ');
String clazz;
String conf;
if (spaceIndex == -1) {
clazz = instanceSpec;
conf = null;
} else {
clazz = instanceSpec.substring(0, spaceIndex);
conf = instanceSpec.substring(spaceIndex+1);
}
try {
Class c = Class.forName(clazz);
i = (Instance) c.getConstructor().newInstance();
Reporter reporter = new MyReporter(child);
i.setReporter(reporter);
i.configure(conf);
i.start();
newList.put(child, i);
int ver = stat.getVersion();
Instance myInstance = i;
DataCallback dc = new MyDataCallback(myNode, myInstance, ver);
Watcher watcher = new MyWatcher(myNode, dc);
zk.getData(myNode, watcher, dc, watcher);
} catch (Exception e) {
LOG.warn("Skipping " + child, e);
if (e.getCause() != null) {
LOG.warn("Caused by", e.getCause());
}
}
}
} else {
// just move it to the new list
newList.put(child, i);
}
}
// kill anything that was removed for the children
for(Map.Entry i: instances.entrySet()) {
i.getValue().stop();
try {
rmnod(reportsNode + '/' + i.getKey());
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
} catch (KeeperException e) {
e.printStackTrace();
}
}
instances = newList;
}
}
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