org.apache.camel.component.consul.policy.ConsulRoutePolicy Maven / Gradle / Ivy
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* 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.camel.component.consul.policy;
import java.math.BigInteger;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import com.google.common.base.Optional;
import com.orbitz.consul.Consul;
import com.orbitz.consul.KeyValueClient;
import com.orbitz.consul.SessionClient;
import com.orbitz.consul.async.ConsulResponseCallback;
import com.orbitz.consul.model.ConsulResponse;
import com.orbitz.consul.model.kv.Value;
import com.orbitz.consul.model.session.ImmutableSession;
import com.orbitz.consul.option.QueryOptions;
import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.Route;
import org.apache.camel.api.management.ManagedAttribute;
import org.apache.camel.api.management.ManagedResource;
import org.apache.camel.component.consul.ConsulConfiguration;
import org.apache.camel.component.consul.ConsulConstants;
import org.apache.camel.support.RoutePolicySupport;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ManagedResource(description = "Route policy using Consul as clustered lock")
public final class ConsulRoutePolicy extends RoutePolicySupport implements CamelContextAware {
private static final Logger LOGGER = LoggerFactory.getLogger(ConsulRoutePolicy.class);
private final Object lock = new Object();
private final AtomicBoolean leader = new AtomicBoolean(false);
private final Set suspendedRoutes = new HashSet<>();
private final AtomicReference index = new AtomicReference<>(BigInteger.valueOf(0));
private Route route;
private CamelContext camelContext;
private String serviceName;
private String servicePath;
private ExecutorService executorService;
private int ttl = 60;
private int lockDelay = 10;
private boolean shouldStopConsumer = true;
private String consulUrl = ConsulConstants.CONSUL_DEFAULT_URL;
private Consul consul;
private SessionClient sessionClient;
private KeyValueClient keyValueClient;
private String sessionId;
public ConsulRoutePolicy() {
}
public ConsulRoutePolicy(String consulUrl) {
this.consulUrl = consulUrl;
}
public ConsulRoutePolicy(ConsulConfiguration configuration) throws Exception {
this.consulUrl = configuration.getUrl();
this.consul = configuration.createConsulClient();
}
@Override
public CamelContext getCamelContext() {
return camelContext;
}
@Override
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
public String getConsulUrl() {
return consulUrl;
}
public void setConsulUrl(String consulUrl) {
this.consulUrl = consulUrl;
}
@Override
public void onInit(Route route) {
super.onInit(route);
this.route = route;
}
@Override
public void onStart(Route route) {
if (!leader.get() && shouldStopConsumer) {
stopConsumer(route);
}
}
@Override
public void onStop(Route route) {
synchronized (lock) {
suspendedRoutes.remove(route);
}
}
@Override
public synchronized void onSuspend(Route route) {
synchronized (lock) {
suspendedRoutes.remove(route);
}
}
@Override
protected void doStart() throws Exception {
ObjectHelper.notNull(camelContext, "camelContext");
ObjectHelper.notNull(serviceName, "serviceName");
ObjectHelper.notNull(servicePath, "servicePath");
if (consul == null) {
Consul.Builder builder = Consul.builder();
if (consulUrl != null) {
builder.withUrl(consulUrl);
}
consul = builder.build();
}
if (sessionClient == null) {
sessionClient = consul.sessionClient();
}
if (keyValueClient == null) {
keyValueClient = consul.keyValueClient();
}
if (sessionId == null) {
sessionId = sessionClient.createSession(
ImmutableSession.builder()
.name(serviceName)
.ttl(ttl + "s")
.lockDelay(lockDelay + "s")
.build()
).getId();
LOGGER.debug("SessionID = {}", sessionId);
if (executorService == null) {
executorService = getCamelContext().getExecutorServiceManager().newSingleThreadExecutor(this, "ConsulRoutePolicy");
}
setLeader(keyValueClient.acquireLock(servicePath, sessionId));
executorService.submit(new Watcher());
}
super.doStart();
}
@Override
protected void doStop() throws Exception {
super.doStop();
if (sessionId != null) {
sessionClient.destroySession(sessionId);
sessionId = null;
}
if (executorService != null) {
getCamelContext().getExecutorServiceManager().shutdownGraceful(executorService);
}
}
// *************************************************************************
//
// *************************************************************************
protected void setLeader(boolean isLeader) {
if (isLeader && leader.compareAndSet(false, isLeader)) {
LOGGER.debug("Leadership taken ({}, {})", serviceName, sessionId);
startAllStoppedConsumers();
} else {
if (!leader.getAndSet(isLeader) && isLeader) {
LOGGER.debug("Leadership lost ({}, {})", serviceName, sessionId);
}
}
}
private void startConsumer(Route route) {
synchronized (lock) {
try {
if (suspendedRoutes.contains(route)) {
startConsumer(route.getConsumer());
suspendedRoutes.remove(route);
}
} catch (Exception e) {
handleException(e);
}
}
}
private void stopConsumer(Route route) {
synchronized (lock) {
try {
if (!suspendedRoutes.contains(route)) {
LOGGER.debug("Stopping consumer for {} ({})", route.getId(), route.getConsumer());
stopConsumer(route.getConsumer());
suspendedRoutes.add(route);
}
} catch (Exception e) {
handleException(e);
}
}
}
private void startAllStoppedConsumers() {
synchronized (lock) {
try {
for (Route route : suspendedRoutes) {
LOGGER.debug("Starting consumer for {} ({})", route.getId(), route.getConsumer());
startConsumer(route.getConsumer());
}
suspendedRoutes.clear();
} catch (Exception e) {
handleException(e);
}
}
}
// *************************************************************************
// Getter/Setters
// *************************************************************************
@ManagedAttribute(description = "The route id")
public String getRouteId() {
if (route != null) {
return route.getId();
}
return null;
}
@ManagedAttribute(description = "The consumer endpoint", mask = true)
public String getEndpointUrl() {
if (route != null && route.getConsumer() != null && route.getConsumer().getEndpoint() != null) {
return route.getConsumer().getEndpoint().toString();
}
return null;
}
public Consul getConsul() {
return consul;
}
@ManagedAttribute(description = "The consul service name")
public String getServiceName() {
return serviceName;
}
public void setServiceName(String serviceName) {
this.serviceName = serviceName;
this.servicePath = String.format("/service/%s/leader", serviceName);
}
@ManagedAttribute(description = "The time to live (seconds)")
public int getTtl() {
return ttl;
}
public void setTtl(int ttl) {
this.ttl = ttl > 10 ? ttl : 10;
}
@ManagedAttribute(description = "The lock delay (seconds)")
public int getLockDelay() {
return lockDelay;
}
public void setLockDelay(int lockDelay) {
this.lockDelay = lockDelay > 10 ? lockDelay : 10;
}
@ManagedAttribute(description = "Whether to stop consumer when starting up and failed to become master")
public boolean isShouldStopConsumer() {
return shouldStopConsumer;
}
public void setShouldStopConsumer(boolean shouldStopConsumer) {
this.shouldStopConsumer = shouldStopConsumer;
}
@ManagedAttribute(description = "Is this route the master or a slave")
public boolean isLeader() {
return leader.get();
}
// *************************************************************************
// Watch
// *************************************************************************
private class Watcher implements Runnable, ConsulResponseCallback> {
@Override
public void onComplete(ConsulResponse> consulResponse) {
if (isRunAllowed()) {
Optional value = consulResponse.getResponse();
if (value.isPresent()) {
Optional sid = value.get().getSession();
if (sid.isPresent() && ObjectHelper.isNotEmpty(sid.get())) {
// If the key is not held by any session, try acquire a
// lock (become leader)
LOGGER.debug("Try to take leadership ...");
setLeader(keyValueClient.acquireLock(servicePath, sessionId));
} else if (!sessionId.equals(sid) && leader.get()) {
// Looks like I've lost leadership
setLeader(false);
}
}
index.set(consulResponse.getIndex());
run();
}
}
@Override
public void onFailure(Throwable throwable) {
handleException(throwable);
}
@Override
public void run() {
if (isRunAllowed()) {
// Refresh session
sessionClient.renewSession(sessionId);
keyValueClient.getValue(
servicePath,
QueryOptions.blockSeconds(ttl / 3, index.get()).build(),
this
);
}
}
}
}
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