hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/container/placement/algorithms/TestSCMContainerPlacementCapacity.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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.hadoop.hdds.scm.container.placement.algorithms;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.hadoop.hdds.conf.ConfigurationSource;
import org.apache.hadoop.hdds.conf.OzoneConfiguration;
import org.apache.hadoop.hdds.protocol.DatanodeDetails;
import org.apache.hadoop.hdds.protocol.MockDatanodeDetails;
import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
import org.apache.hadoop.hdds.scm.exceptions.SCMException;
import org.apache.hadoop.hdds.scm.node.NodeManager;

import org.apache.hadoop.hdds.scm.node.NodeStatus;
import org.junit.Assert;
import org.junit.Test;
import static org.mockito.Matchers.anyObject;
import org.mockito.Mockito;
import static org.mockito.Mockito.when;

/**
 * Test for the scm container placement.
 */
public class TestSCMContainerPlacementCapacity {
  @Test
  public void chooseDatanodes() throws SCMException {
    //given
    ConfigurationSource conf = new OzoneConfiguration();

    List<DatanodeDetails> datanodes = new ArrayList<>();
    for (int i = 0; i < 7; i++) {
      datanodes.add(MockDatanodeDetails.randomDatanodeDetails());
    }

    NodeManager mockNodeManager = Mockito.mock(NodeManager.class);
    when(mockNodeManager.getNodes(NodeStatus.inServiceHealthy()))
        .thenReturn(new ArrayList<>(datanodes));

    when(mockNodeManager.getNodeStat(anyObject()))
        .thenReturn(new SCMNodeMetric(100L, 0L, 100L));
    when(mockNodeManager.getNodeStat(datanodes.get(2)))
        .thenReturn(new SCMNodeMetric(100L, 90L, 10L));
    when(mockNodeManager.getNodeStat(datanodes.get(3)))
        .thenReturn(new SCMNodeMetric(100L, 80L, 20L));
    when(mockNodeManager.getNodeStat(datanodes.get(4)))
        .thenReturn(new SCMNodeMetric(100L, 70L, 30L));

    SCMContainerPlacementCapacity scmContainerPlacementRandom =
        new SCMContainerPlacementCapacity(mockNodeManager, conf, null, true,
            null);

    List<DatanodeDetails> existingNodes = new ArrayList<>();
    existingNodes.add(datanodes.get(0));
    existingNodes.add(datanodes.get(1));

    Map<DatanodeDetails, Integer> selectedCount = new HashMap<>();
    for (DatanodeDetails datanode : datanodes) {
      selectedCount.put(datanode, 0);
    }

    for (int i = 0; i < 1000; i++) {

      //when
      List<DatanodeDetails> datanodeDetails = scmContainerPlacementRandom
          .chooseDatanodes(existingNodes, null, 1, 15);

      //then
      Assert.assertEquals(1, datanodeDetails.size());
      DatanodeDetails datanode0Details = datanodeDetails.get(0);

      Assert.assertNotEquals(
          "Datanode 0 should not been selected: excluded by parameter",
          datanodes.get(0), datanode0Details);
      Assert.assertNotEquals(
          "Datanode 1 should not been selected: excluded by parameter",
          datanodes.get(1), datanode0Details);
      Assert.assertNotEquals(
          "Datanode 2 should not been selected: not enough space there",
          datanodes.get(2), datanode0Details);

      selectedCount
          .put(datanode0Details, selectedCount.get(datanode0Details) + 1);

    }

    //datanode 4 has less space. Should be selected less times.
    Assert.assertTrue(selectedCount.get(datanodes.get(3)) > selectedCount
        .get(datanodes.get(6)));
    Assert.assertTrue(selectedCount.get(datanodes.get(4)) > selectedCount
        .get(datanodes.get(6)));
  }
}