io.helixservice.core.server.HelixServer Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Les Novell
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
*/
/*
* @author Les Novell
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
*/
package io.helixservice.core.server;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;
import io.helixservice.core.component.Component;
import io.helixservice.core.feature.Feature;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.function.Supplier;
/**
* Helix Server
*
* The Helix Server controls the lifecycle of the features
* and components which comprise the service.
*/
public class HelixServer implements Server {
private static final Logger LOG = LoggerFactory.getLogger(HelixServer.class);
private final Supplier bootstrapFeaturesSupplier;
private final Supplier coreFeaturesSupplier;
private Multimap registrationMap = ArrayListMultimap.create();
private ServerState serverState = ServerState.STOPPED;
private boolean bootstrapFeaturesStarted = false;
private List bootstrapFeatures;
private List coreFeatures;
private List features;
private Vertx vertx;
/**
* Create a Helix Server
*
* The server expects a lambda or class that can will instantiate features to be installed.
*
* @param bootstrapFeaturesSupplier Bootstrap features to be started before others. Primarily, these are configuration related features.
* @param coreFeaturesSupplier Core features that will be started after the bootstrap features successfully start.
*/
public HelixServer(Supplier bootstrapFeaturesSupplier, Supplier coreFeaturesSupplier) {
this.bootstrapFeaturesSupplier = bootstrapFeaturesSupplier;
this.coreFeaturesSupplier = coreFeaturesSupplier;
}
/**
* {@inheritDoc}
*/
@Override
public Optional getVertx() {
return Optional.ofNullable(vertx);
}
/**
* {@inheritDoc}
*/
@Override
public ServerState getServerState() {
return serverState;
}
/**
* {@inheritDoc}
*/
@Override
public List getFeatures() {
return features;
}
/**
* {@inheritDoc}
*/
@Override
public Thread start() {
if (serverState != ServerState.STOPPED) {
throw new IllegalStateException("Server state must be STOPPED in order to start the server");
}
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
long start = System.currentTimeMillis();
serverState = ServerState.STARTING;
LOG.info("Starting Helix Server");
HelixServer.this.instantiateFeatures();
for (Feature feature : features) {
feature.logFeatureDetails(LOG);
Multimap registrationMap = feature.getRegistrationMap();
HelixServer.this.registrationMap.putAll(registrationMap);
}
// Start bootstrap features
if (!bootstrapFeaturesStarted) {
for (Feature bootstrapFeature : bootstrapFeatures) {
bootstrapFeature.start(HelixServer.this);
}
bootstrapFeaturesStarted = true;
}
// Initialize Vertx
String numWorkers = System.getProperty("vertx.server.workers", "50");
VertxOptions options = new VertxOptions().setWorkerPoolSize(Integer.parseInt(numWorkers));
vertx = Vertx.vertx(options);
// Start core features
for (Feature coreFeature : coreFeatures) {
coreFeature.start(HelixServer.this);
}
serverState = ServerState.STARTED;
LOG.info("Helix Server started in " + (System.currentTimeMillis() - start) + " ms");
}
});
thread.start();
return thread;
}
/**
* {@inheritDoc}
*/
@Override
public Thread restart() {
if (serverState != ServerState.STARTED) {
throw new IllegalStateException("Server state must be STARTED in order to restart the server");
}
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
LOG.info("Restarting Helix Server");
try {
HelixServer.this.stop(false).join();
HelixServer.this.start().join();
} catch (InterruptedException e) {
LOG.error("Restart HelixServer interrupted ", e);
}
}
});
thread.start();
return thread;
}
private void instantiateFeatures() {
features = new ArrayList<>();
if (this.bootstrapFeatures == null) {
this.bootstrapFeatures = Arrays.asList(bootstrapFeaturesSupplier.get());
features.addAll(this.bootstrapFeatures);
}
this.coreFeatures = Arrays.asList(coreFeaturesSupplier.get());
features.addAll(this.coreFeatures);
}
/**
* {@inheritDoc}
*/
@Override
public Thread stop(boolean immediate) {
if (serverState != ServerState.STARTED) {
throw new IllegalStateException("Server state must be STARTED in order to stop the server");
}
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
List reverseStartOrder = new ArrayList<>(features);
Collections.reverse(reverseStartOrder);
serverState = ServerState.FINISHING;
LOG.info("Finishing Helix Server");
for (Feature feature : reverseStartOrder) {
feature.finish(HelixServer.this);
}
if (!immediate) {
try {
Thread.sleep(15000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
LOG.info("Stopping Helix Server");
serverState = ServerState.STOPPING;
vertx.close((r) -> {
for (Feature feature : reverseStartOrder) {
feature.stop(HelixServer.this);
}
registrationMap.clear();
vertx = null;
serverState = ServerState.STOPPED;
features = null;
bootstrapFeatures = null;
coreFeatures = null;
LOG.info("Stopped Helix Server");
});
}
});
thread.start();
return thread;
}
/**
* {@inheritDoc}
*/
@Override
public Multimap getRegistrationMap() {
return ArrayListMultimap.create(registrationMap);
}
/**
* {@inheritDoc}
*/
@Override
public Collection findByType(String componentType) {
@SuppressWarnings("unchecked")
Collection result = (Collection) registrationMap.get(componentType);
if (result == null) {
result = Collections.emptyList();
}
return result;
}
/**
* {@inheritDoc}
*/
@Override
public T findByType(String componentType, T defaultValue) {
//noinspection unchecked
return Iterables.getFirst((Collection) registrationMap.get(componentType), defaultValue);
}
}