opendaylight/md-sal/sal-distributed-datastore/src/test/java/org/opendaylight/controller/cluster/datastore/entityownership/selectionstrategy/LeastLoadedCandidateSelectionStrategyTest.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  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.cluster.datastore.entityownership.selectionstrategy;
   9
  10 import static org.junit.Assert.assertEquals;
  11 import java.util.ArrayList;
  12 import java.util.Collection;
  13 import java.util.Collections;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16 import org.junit.Test;
  17
  18 public class LeastLoadedCandidateSelectionStrategyTest {
  19
  20     @Test
  21     public void testLeastLoadedStrategy(){
  22         LeastLoadedCandidateSelectionStrategy strategy = new LeastLoadedCandidateSelectionStrategy(0L, Collections.<String, Long>emptyMap());
  23
  24         String owner = strategy.newOwner(null, prepareViableCandidates(3));
  25         assertEquals("member-1", owner);
  26
  27         Map<String, Long> localStatistics = strategy.getLocalStatistics();
  28         assertEquals(1L, (long) localStatistics.get("member-1"));
  29
  30         // member-2 has least load
  31         strategy = new LeastLoadedCandidateSelectionStrategy(0L, prepareStatistics(5,2,4));
  32         owner = strategy.newOwner(null, prepareViableCandidates(3));
  33         assertEquals("member-2", owner);
  34
  35         assertStatistics(strategy.getLocalStatistics(), 5,3,4);
  36
  37         // member-3 has least load
  38         strategy = new LeastLoadedCandidateSelectionStrategy(0L, prepareStatistics(5,7,4));
  39         owner = strategy.newOwner(null, prepareViableCandidates(3));
  40         assertEquals("member-3", owner);
  41
  42         assertStatistics(strategy.getLocalStatistics(), 5,7,5);
  43
  44         // member-1 has least load
  45         strategy = new LeastLoadedCandidateSelectionStrategy(0L, prepareStatistics(1,7,4));
  46         owner = strategy.newOwner(null, prepareViableCandidates(3));
  47         assertEquals("member-1", owner);
  48
  49         assertStatistics(strategy.getLocalStatistics(), 2,7,4);
  50
  51         // Let member-3 become the owner
  52         strategy = new LeastLoadedCandidateSelectionStrategy(0L, prepareStatistics(3,3,0));
  53         owner = strategy.newOwner(null, prepareViableCandidates(3));
  54         assertEquals("member-3", owner);
  55
  56         assertStatistics(strategy.getLocalStatistics(), 3,3,1);
  57
  58         // member-3 is no longer viable so choose a new owner
  59         owner = strategy.newOwner("member-3", prepareViableCandidates(2));
  60         assertEquals("member-1", owner);
  61
  62         assertStatistics(strategy.getLocalStatistics(), 4,3,0);
  63
  64     }
  65
  66     private static Map<String, Long> prepareStatistics(long... count){
  67         Map<String, Long> statistics = new HashMap<>();
  68         for(int i=0;i<count.length;i++){
  69             statistics.put("member-" + (i+1), count[i]);
  70         }
  71         return statistics;
  72     }
  73
  74     private static Collection<String> prepareViableCandidates(int count){
  75         Collection<String> viableCandidates = new ArrayList<>();
  76         for(int i=0;i<count;i++){
  77             viableCandidates.add("member-" + (i+1));
  78         }
  79         return viableCandidates;
  80     }
  81
  82     private static void assertStatistics(Map<String, Long> statistics, long... count){
  83         for(int i=0;i<count.length;i++){
  84             assertEquals(count[i], (long) statistics.get("member-" + (i+1)));
  85         }
  86     }
  87 }