co.cask.tigon.internal.app.runtime.distributed.AbstractServiceTwillRunnable.java Source code

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Here is the source code for co.cask.tigon.internal.app.runtime.distributed.AbstractServiceTwillRunnable.java

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/*
 * 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.tigon.internal.app.runtime.distributed;

import co.cask.tigon.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 Transaction Manager Service.
 */
public abstract class AbstractServiceTwillRunnable extends AbstractTwillRunnable {
    private static final Logger LOG = LoggerFactory.getLogger(AbstractServiceTwillRunnable.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 AbstractServiceTwillRunnable(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() {
        LOG.info("Stopping Service Twill Runnable : {}", name);
        if (runThread != null) {
            runThread.interrupt();
        }
    }

    /**
     * Class extending {@link AbstractServiceTwillRunnable} 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);
}