geode-core/src/main/java/org/apache/geode/internal/cache/ServerPingMessage.java

/*
 * 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.geode.internal.cache;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import org.apache.geode.distributed.internal.ClusterDistributionManager;
import org.apache.geode.distributed.internal.DistributionManager;
import org.apache.geode.distributed.internal.InternalDistributedSystem;
import org.apache.geode.distributed.internal.PooledDistributionMessage;
import org.apache.geode.distributed.internal.ReplyMessage;
import org.apache.geode.distributed.internal.ReplyProcessor21;
import org.apache.geode.distributed.internal.membership.InternalDistributedMember;
import org.apache.geode.internal.Version;

/**
 * Ping to check if a server is alive. It waits for a specified time before returning false.
 *
 */
public class ServerPingMessage extends PooledDistributionMessage {
  private int processorId = 0;

  public ServerPingMessage() {}


  public ServerPingMessage(ReplyProcessor21 processor) {
    this.processorId = processor.getProcessorId();
  }


  @Override
  public int getDSFID() {
    return SERVER_PING_MESSAGE;
  }

  /**
   * Sends a ping message. The pre-GFXD_101 recipients are filtered out and it is assumed that they
   * are pingable.
   *
   * @return true if all the recipients are pingable
   */
  public static boolean send(InternalCache cache, Set<InternalDistributedMember> recipients) {

    InternalDistributedSystem ids = cache.getInternalDistributedSystem();
    DistributionManager dm = ids.getDistributionManager();
    Set<InternalDistributedMember> filteredRecipients = new HashSet<InternalDistributedMember>();

    // filtered recipients
    for (InternalDistributedMember recipient : recipients) {
      if (Version.GFE_81.compareTo(recipient.getVersionObject()) <= 0) {
        filteredRecipients.add(recipient);
      }
    }
    if (filteredRecipients.size() == 0)
      return true;

    ReplyProcessor21 replyProcessor = new ReplyProcessor21(dm, filteredRecipients);
    ServerPingMessage spm = new ServerPingMessage(replyProcessor);

    spm.setRecipients(filteredRecipients);
    Set failedServers = null;
    try {
      if (cache.getLogger().fineEnabled())
        cache.getLogger().fine("Pinging following servers " + filteredRecipients);
      failedServers = dm.putOutgoing(spm);

      // wait for the replies for timeout msecs
      boolean receivedReplies = replyProcessor.waitForReplies(0L);

      dm.getCancelCriterion().checkCancelInProgress(null);

      // If the reply is not received in the stipulated time, throw an exception
      if (!receivedReplies) {
        cache.getLogger().error(
            String.format("Could not ping one of the following servers: %s", filteredRecipients));
        return false;
      }
    } catch (Throwable e) {
      cache.getLogger().error(
          String.format("Could not ping one of the following servers: %s", filteredRecipients), e);
      return false;
    }

    if (failedServers == null || failedServers.size() == 0)
      return true;

    cache.getLogger()
        .info(String.format("Could not ping one of the following servers: %s", failedServers));

    return false;
  }

  @Override
  protected void process(ClusterDistributionManager dm) {
    // do nothing. We are just pinging the server. send the reply back.
    ReplyMessage.send(getSender(), this.processorId, null, dm);
  }


  @Override
  public void toData(DataOutput out) throws IOException {
    super.toData(out);
    out.writeInt(this.processorId);
  }

  @Override
  public void fromData(DataInput in) throws IOException, ClassNotFoundException {
    super.fromData(in);
    this.processorId = in.readInt();
  }

  @Override
  public int getProcessorId() {
    return this.processorId;
  }
}