com.gemstone.gemfire.cache.client.internal.ConnectionSource Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of gemfire-core Show documentation

TIBCO ComputeDB store based off Pivotal GemFireXD

There is a newer version: 2.0-BETA

/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
 *
 * 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. See accompanying
 * LICENSE file.
 */
package com.gemstone.gemfire.cache.client.internal;

import java.util.List;
import java.util.Set;

import com.gemstone.gemfire.distributed.internal.ServerLocation;
import com.gemstone.gemfire.internal.cache.tier.sockets.ClientProxyMembershipID;


/**
 * A source for discovering servers and finding the least loaded
 * server to connect to.
 * @author dsmith
 * @since 5.7
 *
 */
public interface ConnectionSource {
  
  ServerLocation findServer(Set/**/ excludedServers);

  /**
   * Asks if we should replace a connection to currentServer
   * with one to the returned server.
   * @param currentServer the server we currently have a connection to.
   * @param excludedServers the replacement server can not be one in this set
   * @return the server we should connect to;
   *         currentServer if a replacement is not needed;
   *         null if no server found
   */
  ServerLocation findReplacementServer(ServerLocation currentServer, Set/**/ excludedServers);
  
  /**
   * Find the servers to host the queue
   * 
   * @param excludedServers
   *                the servers to exclude from the search
   * @param numServers
   *                the number of servers to find, or -1 if we should just find
   *                all of them
   * @param proxyId
   *                the proxy id for this client
   * @param findDurableQueue
   *                if true, the source should make an effort to find the
   *                durable queues for this client
   * @return a list of locations to connect to
   */
  List/* ServerLocation */findServersForQueue(
      Set/*  */excludedServers, int numServers,
      ClientProxyMembershipID proxyId, boolean findDurableQueue);

  void start(InternalPool poolImpl);

  void stop();
  
  /**
   * Check to see if the load on the servers is balanced, according
   * to this connection source.
   * @return true if the servers have balanced load.
   */
  boolean isBalanced();
}