opendaylight/samples/loadbalancer/src/main/java/org/opendaylight/controller/samples/loadbalancer/policies/RandomLBPolicy.java

   1 /*
   2  * Copyright IBM Corporation, 2013.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.samples.loadbalancer.policies;
   9
  10 import java.util.ArrayList;
  11 import java.util.HashMap;
  12 import java.util.Random;
  13
  14 import org.opendaylight.controller.samples.loadbalancer.ConfigManager;
  15 import org.opendaylight.controller.samples.loadbalancer.entities.Client;
  16 import org.opendaylight.controller.samples.loadbalancer.entities.Pool;
  17 import org.opendaylight.controller.samples.loadbalancer.entities.PoolMember;
  18 import org.opendaylight.controller.samples.loadbalancer.entities.VIP;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 /**
  23  * This class implements the random load balancing policy.
  24  *
  25  */
  26 public class RandomLBPolicy implements ILoadBalancingPolicy {
  27
  28     /*
  29      * Instance logger
  30      */
  31     private static final Logger rLogger = LoggerFactory.getLogger(RandomLBPolicy.class);
  32
  33     /*
  34      * Reference to the configuration manager. This reference is passed from load balancer
  35      * class.
  36      */
  37     private ConfigManager cmgr;
  38
  39     /*
  40      * Mapping between the client and the pool member that serves all traffic for that client.
  41      */
  42     private HashMap<Client, PoolMember> clientMemberMap;
  43
  44     /*
  45      * Random generator
  46      */
  47     Random randomGenerator = null;
  48
  49     @SuppressWarnings("unused")
  50     private RandomLBPolicy(){}
  51
  52     public RandomLBPolicy(ConfigManager cmgr){
  53         this.cmgr = cmgr;
  54         this.clientMemberMap = new HashMap<Client, PoolMember>();
  55         randomGenerator = new Random();
  56     }
  57     @Override
  58     public String getPoolMemberForClient(Client source, VIP dest){
  59
  60         rLogger.trace("Received traffic from client : {} for VIP : {} ",source, dest);
  61
  62         syncWithLoadBalancerData();
  63
  64         PoolMember pm= null;
  65
  66         if(this.clientMemberMap.containsKey(source)){
  67             pm= this.clientMemberMap.get(source);
  68             rLogger.trace("Client {} had sent traffic before,new traffic will be routed to the same pool member {}",source,pm);
  69         }else{
  70             Pool pool = null;
  71             pool = this.cmgr.getPool(dest.getPoolName());
  72             int memberNum = this.randomGenerator.nextInt(pool.getAllMembers().size()-1);
  73             pm = pool.getAllMembers().get(memberNum);
  74             this.clientMemberMap.put(source, pm );
  75             rLogger.trace("Network traffic from client {} will be directed to pool member {}",pm);
  76         }
  77         return pm.getIp();
  78     }
  79
  80     /*
  81      * This method does the clean up. Whenever a new client packet arrives with a given VIP,
  82      * this method checks the current configuration to see if any pool members have been deleted and
  83      * cleans up the metadata stored by this loadbalancing algorithm.
  84      */
  85     private void syncWithLoadBalancerData(){
  86         rLogger.debug("[Client - PoolMember] table before cleanup : {}",this.clientMemberMap.toString());
  87
  88         ArrayList<Client> removeClient = new ArrayList<Client>();
  89
  90         if(this.clientMemberMap.size() != 0){
  91             for(Client client : this.clientMemberMap.keySet()){
  92
  93                 if(!this.cmgr.memberExists(this.clientMemberMap.get(client).getName(),
  94                                                 this.clientMemberMap.get(client).getPoolName())){
  95                     removeClient.add(client);
  96                 }
  97             }
  98         }
  99
 100         for(Client client : removeClient){
 101             this.clientMemberMap.remove(client);
 102
 103             rLogger.debug("Removed client : {} ",client);
 104         }
 105         rLogger.debug("[Client - PoolMember] table after cleanup : {}",this.clientMemberMap.toString());
 106     }
 107
 108 }