/*
* Copyright © 2014 Cask Data, Inc.
*
* Licensed 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 co.cask.cdap.common.twill;
import co.cask.cdap.common.conf.CConfiguration;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.Service;
import com.google.common.util.concurrent.SettableFuture;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.twill.api.AbstractTwillRunnable;
import org.apache.twill.api.TwillContext;
import org.apache.twill.api.TwillRunnableSpecification;
import org.apache.twill.common.ServiceListenerAdapter;
import org.apache.twill.common.Services;
import org.apache.twill.common.Threads;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
/**
* Abstract TwillRunnable class for Master system service.
*/
public abstract class AbstractMasterTwillRunnable extends AbstractTwillRunnable {
private static final Logger LOG = LoggerFactory.getLogger(AbstractMasterTwillRunnable.class);
protected String name;
private String cConfName;
private String hConfName;
private Configuration hConf;
private CConfiguration cConf;
private List<Service> services;
private volatile Thread runThread;
public AbstractMasterTwillRunnable(String name, String cConfName, String hConfName) {
this.name = name;
this.cConfName = cConfName;
this.hConfName = hConfName;
}
@Override
public TwillRunnableSpecification configure() {
return TwillRunnableSpecification.Builder.with()
.setName(name)
.withConfigs(ImmutableMap.of("cConf", cConfName, "hConf", hConfName))
.build();
}
@Override
public final void initialize(TwillContext context) {
super.initialize(context);
name = context.getSpecification().getName();
Map<String, String> configs = context.getSpecification().getConfigs();
try {
// Load configuration
hConf = new Configuration();
hConf.clear();
hConf.addResource(new File(configs.get("hConf")).toURI().toURL());
UserGroupInformation.setConfiguration(hConf);
cConf = CConfiguration.create();
cConf.clear();
cConf.addResource(new File(configs.get("cConf")).toURI().toURL());
LOG.debug("{} cConf {}", name, cConf);
LOG.debug("{} HBase conf {}", name, hConf);
doInit(context);
services = Lists.newArrayList();
getServices(services);
Preconditions.checkArgument(!services.isEmpty(), "Should have at least one service");
} catch (Throwable t) {
throw Throwables.propagate(t);
}
}
@Override
public void run() {
runThread = Thread.currentThread();
LOG.info("Starting runnable {}", name);
List<ListenableFuture<Service.State>> completions = Lists.newArrayList();
for (Service service : services) {
SettableFuture<Service.State> completion = SettableFuture.create();
service.addListener(createServiceListener(completion), Threads.SAME_THREAD_EXECUTOR);
completions.add(completion);
}
Services.chainStart(services.get(0), services.subList(1, services.size()).toArray(new Service[0]));
LOG.info("Runnable started {}", name);
try {
Futures.allAsList(completions).get();
} catch (InterruptedException e) {
LOG.debug("Waiting on latch interrupted {}", name);
Thread.currentThread().interrupt();
} catch (ExecutionException e) {
LOG.error("Exception in service.", e);
throw Throwables.propagate(e);
}
List<Service> reverse = Lists.reverse(services);
Services.chainStop(reverse.get(0), reverse.subList(1, reverse.size()).toArray(new Service[0]));
LOG.info("Runnable stopped {}", name);
}
private Service.Listener createServiceListener(final SettableFuture<Service.State> completion) {
return new ServiceListenerAdapter() {
@Override
public void terminated(Service.State from) {
completion.set(from);
}
@Override
public void failed(Service.State from, Throwable failure) {
completion.setException(failure);
}
};
}
protected final Configuration getConfiguration() {
return hConf;
}
protected final CConfiguration getCConfiguration() {
return cConf;
}
@Override
public void stop() {
if (runThread != null) {
runThread.interrupt();
}
}
/**
* Class extending AbstractMasterTwillRunnable should populate services
* with a list of Services which will be started in increasing order of index.
* The services will be stopped in the reverse order.
*/
protected abstract void getServices(List<? super Service> services);
/**
* Performs initialization task.
*/
protected abstract void doInit(TwillContext context);
}