public virtual void TestChooseTargetWithDependencies()
{
for (int i = 0; i < NumOfDatanodes; i++)
{
cluster.Remove(dataNodes[i]);
}
for (int i_1 = 0; i_1 < NumOfDatanodesMoreTargets; i_1++)
{
DatanodeDescriptor node = dataNodesInMoreTargetsCase[i_1];
if (cluster.Contains(node))
{
cluster.Remove(node);
}
}
Host2NodesMap host2DatanodeMap = namenode.GetNamesystem().GetBlockManager().GetDatanodeManager
().GetHost2DatanodeMap();
for (int i_2 = 0; i_2 < NumOfDatanodesForDependencies; i_2++)
{
cluster.Add(dataNodesForDependencies[i_2]);
host2DatanodeMap.Add(dataNodesForDependencies[i_2]);
}
//add dependencies (node1 <-> node2, and node3<->node4)
dataNodesForDependencies[1].AddDependentHostName(dataNodesForDependencies[2].GetHostName
());
dataNodesForDependencies[2].AddDependentHostName(dataNodesForDependencies[1].GetHostName
());
dataNodesForDependencies[3].AddDependentHostName(dataNodesForDependencies[4].GetHostName
());
dataNodesForDependencies[4].AddDependentHostName(dataNodesForDependencies[3].GetHostName
());
//Update heartbeat
for (int i_3 = 0; i_3 < NumOfDatanodesForDependencies; i_3++)
{
UpdateHeartbeatWithUsage(dataNodesForDependencies[i_3], 2 * HdfsConstants.MinBlocksForWrite
* BlockSize, 0L, 2 * HdfsConstants.MinBlocksForWrite * BlockSize, 0L, 0L, 0L, 0
, 0);
}
IList <DatanodeStorageInfo> chosenNodes = new AList <DatanodeStorageInfo>();
DatanodeStorageInfo[] targets;
ICollection <Node> excludedNodes = new HashSet <Node>();
excludedNodes.AddItem(dataNodesForDependencies[5]);
//try to select three targets as there are three node groups
targets = ChooseTarget(3, dataNodesForDependencies[1], chosenNodes, excludedNodes
);
//Even there are three node groups, verify that
//only two targets are selected due to dependencies
NUnit.Framework.Assert.AreEqual(targets.Length, 2);
NUnit.Framework.Assert.AreEqual(targets[0], storagesForDependencies[1]);
NUnit.Framework.Assert.IsTrue(targets[1].Equals(storagesForDependencies[3]) || targets
[1].Equals(storagesForDependencies[4]));
//verify that all data nodes are in the excluded list
NUnit.Framework.Assert.AreEqual(excludedNodes.Count, NumOfDatanodesForDependencies
);
for (int i_4 = 0; i_4 < NumOfDatanodesForDependencies; i_4++)
{
NUnit.Framework.Assert.IsTrue(excludedNodes.Contains(dataNodesForDependencies[i_4
]));
}
}
/// <summary>
/// Get an instance of the configured Block Placement Policy based on the
/// the configuration property
/// <see cref="Org.Apache.Hadoop.Hdfs.DFSConfigKeys.DfsBlockReplicatorClassnameKey"/>
/// .
/// </summary>
/// <param name="conf">the configuration to be used</param>
/// <param name="stats">an object that is used to retrieve the load on the cluster</param>
/// <param name="clusterMap">the network topology of the cluster</param>
/// <returns>an instance of BlockPlacementPolicy</returns>
public static BlockPlacementPolicy GetInstance(Configuration conf, FSClusterStats
stats, NetworkTopology clusterMap, Host2NodesMap host2datanodeMap)
{
Type replicatorClass = conf.GetClass <BlockPlacementPolicy>(DFSConfigKeys.DfsBlockReplicatorClassnameKey
, DFSConfigKeys.DfsBlockReplicatorClassnameDefault);
BlockPlacementPolicy replicator = ReflectionUtils.NewInstance(replicatorClass, conf
);
replicator.Initialize(conf, stats, clusterMap, host2datanodeMap);
return(replicator);
}
protected internal override void Initialize(Configuration conf, FSClusterStats stats
, NetworkTopology clusterMap, Host2NodesMap host2datanodeMap)
{
base.Initialize(conf, stats, clusterMap, host2datanodeMap);
}
/// <summary>Used to setup a BlockPlacementPolicy object.</summary>
/// <remarks>
/// Used to setup a BlockPlacementPolicy object. This should be defined by
/// all implementations of a BlockPlacementPolicy.
/// </remarks>
/// <param name="conf">the configuration object</param>
/// <param name="stats">retrieve cluster status from here</param>
/// <param name="clusterMap">cluster topology</param>
protected internal abstract void Initialize(Configuration conf, FSClusterStats stats
, NetworkTopology clusterMap, Host2NodesMap host2datanodeMap);