/**
* Copyright 2005-2014 Red Hat, Inc.
*
* Red Hat 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 io.fabric8.mq.fabric;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import com.fasterxml.jackson.annotation.JsonProperty;
import io.fabric8.groups.internal.ManagedGroupFactory;
import io.fabric8.groups.internal.ManagedGroupFactoryBuilder;
import org.apache.activemq.command.DiscoveryEvent;
import org.apache.activemq.transport.discovery.DiscoveryAgent;
import org.apache.activemq.transport.discovery.DiscoveryListener;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.RetryOneTime;
import io.fabric8.groups.GroupListener;
import io.fabric8.groups.Group;
import io.fabric8.groups.MultiGroup;
import io.fabric8.groups.NodeState;
import io.fabric8.zookeeper.curator.CuratorACLManager;
import io.fabric8.zookeeper.utils.ZooKeeperUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class FabricDiscoveryAgent implements DiscoveryAgent, Callable {
private static final Logger LOG = LoggerFactory.getLogger(FabricDiscoveryAgent.class);
protected CuratorFramework curator;
private boolean managedZkClient;
private String groupName = "default";
private AtomicBoolean running=new AtomicBoolean();
private final AtomicReference<DiscoveryListener> discoveryListener = new AtomicReference<DiscoveryListener>();
private final HashMap<String, SimpleDiscoveryEvent> discoveredServices = new HashMap<String, SimpleDiscoveryEvent>();
private final AtomicInteger startCounter = new AtomicInteger(0);
private long initialReconnectDelay = 1000;
private long maxReconnectDelay = 1000 * 30;
private long backOffMultiplier = 2;
private boolean useExponentialBackOff=true;
private int maxReconnectAttempts = 0;
private final Object sleepMutex = new Object();
private long minConnectTime = 5000;
private String id;
private String agent;
MultiGroup<ActiveMQNode> group;
ManagedGroupFactory factory;
List<String> services = new ArrayList<String>();
public void setGroupName(String groupName) {
this.groupName = groupName;
}
public static class ActiveMQNode extends NodeState {
public ActiveMQNode() {
super();
}
public ActiveMQNode(String id, String container) {
super(id, container);
}
@JsonProperty
String[] services;
}
ActiveMQNode createState() {
ActiveMQNode state = new ActiveMQNode(id, agent);
state.id = id;
state.services = services.toArray(new String[services.size()]);
return state;
}
class SimpleDiscoveryEvent extends DiscoveryEvent {
private int connectFailures;
private long reconnectDelay = initialReconnectDelay;
private long connectTime = System.currentTimeMillis();
private AtomicBoolean failed = new AtomicBoolean(false);
private AtomicBoolean removed = new AtomicBoolean(false);
public SimpleDiscoveryEvent(String service) {
super(service);
}
}
synchronized public void registerService(String service) throws IOException {
services.add(service);
updateClusterState();
}
public void updateClusterState() {
if (startCounter.get() > 0 ) {
if( id==null )
throw new IllegalStateException("You must configure the id of the fabric discovery if you want to register services");
group.update(createState());
}
}
public void serviceFailed(DiscoveryEvent devent) throws IOException {
final SimpleDiscoveryEvent event = (SimpleDiscoveryEvent)devent;
if (event.failed.compareAndSet(false, true)) {
discoveryListener.get().onServiceRemove(event);
if(!event.removed.get()) {
// Setup a thread to re-raise the event...
Thread thread = new Thread() {
public void run() {
// We detect a failed connection attempt because the service
// fails right away.
if (event.connectTime + minConnectTime > System.currentTimeMillis()) {
LOG.debug("Failure occurred soon after the discovery event was generated. It will be classified as a connection failure: "+event);
event.connectFailures++;
if (maxReconnectAttempts > 0 && event.connectFailures >= maxReconnectAttempts) {
LOG.debug("Reconnect attempts exceeded "+maxReconnectAttempts+" tries. Reconnecting has been disabled.");
return;
}
synchronized (sleepMutex) {
try {
if (!running.get() || event.removed.get()) {
return;
}
LOG.debug("Waiting "+event.reconnectDelay+" ms before attempting to reconnect.");
sleepMutex.wait(event.reconnectDelay);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
return;
}
}
if (!useExponentialBackOff) {
event.reconnectDelay = initialReconnectDelay;
} else {
// Exponential increment of reconnect delay.
event.reconnectDelay *= backOffMultiplier;
if (event.reconnectDelay > maxReconnectDelay) {
event.reconnectDelay = maxReconnectDelay;
}
}
} else {
event.connectFailures = 0;
event.reconnectDelay = initialReconnectDelay;
}
if (!running.get() || event.removed.get()) {
return;
}
event.connectTime = System.currentTimeMillis();
event.failed.set(false);
discoveryListener.get().onServiceAdd(event);
}
};
thread.setDaemon(true);
thread.start();
}
}
}
public void setDiscoveryListener(DiscoveryListener discoveryListener) {
this.discoveryListener.set(discoveryListener);
}
synchronized public void start() throws Exception {
if( startCounter.addAndGet(1)==1 ) {
running.set(true);
if (curator != null) {
managedZkClient = false;
}
getGroup().add(new GroupListener<ActiveMQNode>() {
@Override
public void groupEvent(Group<ActiveMQNode> group, GroupEvent event) {
Map<String, ActiveMQNode> masters = new HashMap<String, ActiveMQNode>();
for (ActiveMQNode node : group.members().values()) {
if (!masters.containsKey(node.id)) {
masters.put(node.id, node);
}
}
update(masters.values());
}
});
if( id!=null ) {
group.update(createState());
}
group.start();
}
}
synchronized public void stop() throws Exception {
if( startCounter.decrementAndGet()==0 ) {
running.set(false);
try {
if (group != null) {
group.close();
}
} catch (Throwable ignore) {
// Most likely a ServiceUnavailableException: The Blueprint container is being or has been destroyed
}
if( managedZkClient ) {
try {
curator.close();
} catch (Throwable ignore) {
// Most likely a ServiceUnavailableException: The Blueprint container is being or has been destroyed
}
curator = null;
}
}
}
private void update(Collection<ActiveMQNode> members) {
// Find new registered services...
DiscoveryListener discoveryListener = this.discoveryListener.get();
if(discoveryListener!=null) {
HashSet<String> activeServices = new HashSet<String>();
for(ActiveMQNode m : members) {
for(String service: m.services) {
String resolved = service;
try {
resolved = ZooKeeperUtils.getSubstitutedData(curator, service);
} catch (Exception e) {
// ignore, we'll use unresolved value
}
// Lets only discover openwire service URLs
if( resolved.startsWith("tcp:")
|| resolved.startsWith("ssl:")
|| resolved.startsWith("nio:")
|| resolved.startsWith("nio+ssl:")) {
activeServices.add(resolved);
}
}
}
// If there is error talking the the central server, then activeServices == null
if( members !=null ) {
synchronized(discoveredServices) {
HashSet<String> removedServices = new HashSet<String>(discoveredServices.keySet());
removedServices.removeAll(activeServices);
HashSet<String> addedServices = new HashSet<String>(activeServices);
addedServices.removeAll(discoveredServices.keySet());
addedServices.removeAll(removedServices);
for (String service : addedServices) {
SimpleDiscoveryEvent e = new SimpleDiscoveryEvent(service);
discoveredServices.put(service, e);
discoveryListener.onServiceAdd(e);
}
for (String service : removedServices) {
SimpleDiscoveryEvent e = discoveredServices.remove(service);
if( e !=null ) {
e.removed.set(true);
}
discoveryListener.onServiceRemove(e);
}
}
}
}
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public List<String> getServices() {
return services;
}
public void setServices(String[] services) {
this.services.clear();
for(String s:services) {
this.services.add(s);
}
updateClusterState();
}
public MultiGroup<ActiveMQNode> getGroup() throws Exception {
if (group == null) {
factory = ManagedGroupFactoryBuilder.create(curator, getClass().getClassLoader(), this);
group = (MultiGroup)factory.createMultiGroup("/fabric/registry/clusters/amq/" + groupName, ActiveMQNode.class);
curator = factory.getCurator();
}
return group;
}
@Override
public Object call() throws Exception {
LOG.info("Using local ZKClient");
managedZkClient = true;
CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
.connectString(System.getProperty("zookeeper.url", "localhost:2181"))
.retryPolicy(new RetryOneTime(1000))
.connectionTimeoutMs(10000);
String password = System.getProperty("zookeeper.password", "admin");
if (password != null && !password.isEmpty()) {
builder.aclProvider(new CuratorACLManager());
builder.authorization("digest", ("fabric:"+password).getBytes());
}
CuratorFramework client = builder.build();
client.start();
client.getZookeeperClient().blockUntilConnectedOrTimedOut();
return client;
}
public CuratorFramework getCurator() {
return curator;
}
public void setCurator(CuratorFramework curator) {
this.curator = curator;
}
public String getAgent() {
return agent;
}
public void setAgent(String agent) {
this.agent = agent;
}
}