io.druid.indexing.common.actions.RemoteTaskActionClient Maven / Gradle / Ivy

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group 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 io.druid.indexing.common.actions;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Charsets;
import com.google.common.base.Throwables;
import com.metamx.common.ISE;
import com.metamx.common.logger.Logger;
import com.metamx.http.client.HttpClient;
import com.metamx.http.client.Request;
import com.metamx.http.client.response.StatusResponseHandler;
import com.metamx.http.client.response.StatusResponseHolder;
import io.druid.client.selector.Server;
import io.druid.curator.discovery.ServerDiscoverySelector;
import io.druid.indexing.common.RetryPolicy;
import io.druid.indexing.common.RetryPolicyFactory;
import io.druid.indexing.common.task.Task;
import org.jboss.netty.channel.ChannelException;
import org.jboss.netty.handler.codec.http.HttpMethod;
import org.joda.time.Duration;

import javax.ws.rs.core.MediaType;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Map;
import java.util.Random;

public class RemoteTaskActionClient implements TaskActionClient
{
  private final Task task;
  private final HttpClient httpClient;
  private final ServerDiscoverySelector selector;
  private final RetryPolicyFactory retryPolicyFactory;
  private final ObjectMapper jsonMapper;
  private final Random random = new Random();

  private static final Logger log = new Logger(RemoteTaskActionClient.class);

  public RemoteTaskActionClient(
      Task task,
      HttpClient httpClient,
      ServerDiscoverySelector selector,
      RetryPolicyFactory retryPolicyFactory,
      ObjectMapper jsonMapper
  )
  {
    this.task = task;
    this.httpClient = httpClient;
    this.selector = selector;
    this.retryPolicyFactory = retryPolicyFactory;
    this.jsonMapper = jsonMapper;
  }

  @Override
  public  RetType submit(TaskAction taskAction) throws IOException
  {
    log.info("Performing action for task[%s]: %s", task.getId(), taskAction);

    byte[] dataToSend = jsonMapper.writeValueAsBytes(new TaskActionHolder(task, taskAction));

    final RetryPolicy retryPolicy = retryPolicyFactory.makeRetryPolicy();

    while (true) {
      try {
        final Server server;
        final URI serviceUri;
        try {
          server = getServiceInstance();
          serviceUri = makeServiceUri(server);
        }
        catch (Exception e) {
          // Want to retry, so throw an IOException.
          throw new IOException("Failed to locate service uri", e);
        }

        final StatusResponseHolder response;

        log.info("Submitting action for task[%s] to overlord[%s]: %s", task.getId(), serviceUri, taskAction);

        try {
          response = httpClient.go(
              new Request(HttpMethod.POST, serviceUri.toURL())
                  .setContent(MediaType.APPLICATION_JSON, dataToSend),
              new StatusResponseHandler(Charsets.UTF_8)
          ).get();
        }
        catch (Exception e) {
          Throwables.propagateIfInstanceOf(e.getCause(), IOException.class);
          Throwables.propagateIfInstanceOf(e.getCause(), ChannelException.class);
          throw Throwables.propagate(e);
        }

        if (response.getStatus().getCode() / 200 == 1) {
          final Map responseDict = jsonMapper.readValue(
              response.getContent(),
              new TypeReference>()
              {
              }
          );
          return jsonMapper.convertValue(responseDict.get("result"), taskAction.getReturnTypeReference());
        } else {
          // Want to retry, so throw an IOException.
          throw new IOException(
              String.format(
                  "Scary HTTP status returned: %s. Check your overlord[%s] logs for exceptions.",
                  response.getStatus(),
                  server.getHost()
              )
          );
        }
      }
      catch (IOException | ChannelException e) {
        log.warn(e, "Exception submitting action for task[%s]", task.getId());

        final Duration delay = retryPolicy.getAndIncrementRetryDelay();
        if (delay == null) {
          throw e;
        } else {
          try {
            final long sleepTime = jitter(delay.getMillis());
            log.info("Will try again in [%s].", new Duration(sleepTime).toString());
            Thread.sleep(sleepTime);
          }
          catch (InterruptedException e2) {
            throw Throwables.propagate(e2);
          }
        }
      }
    }
  }

  private long jitter(long input){
    final double jitter = random.nextGaussian() * input / 4.0;
    long retval = input + (long)jitter;
    return retval < 0 ? 0 : retval;
  }

  private URI makeServiceUri(final Server instance) throws URISyntaxException
  {
    return new URI(instance.getScheme(), null, instance.getAddress(), instance.getPort(), "/druid/indexer/v1/action", null, null);
  }

  private Server getServiceInstance()
  {
    final Server instance = selector.pick();
    if (instance == null) {
      throw new ISE("Cannot find instance of indexer to talk to!");
    } else {
      return instance;
    }
  }
}