/// <summary>
/// Find other nodes in the same nodegroup of <i>localMachine</i> and add them
/// into <i>excludeNodes</i> as replica should not be duplicated for nodes
/// within the same nodegroup
/// </summary>
/// <returns>number of new excluded nodes</returns>
protected internal override int AddToExcludedNodes(DatanodeDescriptor chosenNode,
ICollection <Node> excludedNodes)
{
int countOfExcludedNodes = 0;
string nodeGroupScope = chosenNode.GetNetworkLocation();
IList <Node> leafNodes = clusterMap.GetLeaves(nodeGroupScope);
foreach (Node leafNode in leafNodes)
{
if (excludedNodes.AddItem(leafNode))
{
// not a existing node in excludedNodes
countOfExcludedNodes++;
}
}
countOfExcludedNodes += AddDependentNodesToExcludedNodes(chosenNode, excludedNodes
);
return(countOfExcludedNodes);
}
/// <exception cref="Org.Apache.Hadoop.Hdfs.Server.Blockmanagement.BlockPlacementPolicy.NotEnoughReplicasException
/// "/>
protected internal override DatanodeStorageInfo ChooseLocalRack(Node localMachine
, ICollection <Node> excludedNodes, long blocksize, int maxNodesPerRack, IList <DatanodeStorageInfo
> results, bool avoidStaleNodes, EnumMap <StorageType, int> storageTypes)
{
// no local machine, so choose a random machine
if (localMachine == null)
{
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
// choose one from the local rack, but off-nodegroup
try
{
string scope = NetworkTopology.GetFirstHalf(localMachine.GetNetworkLocation());
return(ChooseRandom(scope, excludedNodes, blocksize, maxNodesPerRack, results, avoidStaleNodes
, storageTypes));
}
catch (BlockPlacementPolicy.NotEnoughReplicasException)
{
// find the second replica
DatanodeDescriptor newLocal = SecondNode(localMachine, results);
if (newLocal != null)
{
try
{
return(ChooseRandom(clusterMap.GetRack(newLocal.GetNetworkLocation()), excludedNodes
, blocksize, maxNodesPerRack, results, avoidStaleNodes, storageTypes));
}
catch (BlockPlacementPolicy.NotEnoughReplicasException)
{
//otherwise randomly choose one from the network
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
}
else
{
//otherwise randomly choose one from the network
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
}
}
/* choose one node from the nodegroup that <i>localMachine</i> is on.
* if no such node is available, choose one node from the nodegroup where
* a second replica is on.
* if still no such node is available, choose a random node in the cluster.
* @return the chosen node
*/
/// <exception cref="Org.Apache.Hadoop.Hdfs.Server.Blockmanagement.BlockPlacementPolicy.NotEnoughReplicasException
/// "/>
private DatanodeStorageInfo ChooseLocalNodeGroup(NetworkTopologyWithNodeGroup clusterMap
, Node localMachine, ICollection <Node> excludedNodes, long blocksize, int maxNodesPerRack
, IList <DatanodeStorageInfo> results, bool avoidStaleNodes, EnumMap <StorageType,
int> storageTypes)
{
// no local machine, so choose a random machine
if (localMachine == null)
{
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
// choose one from the local node group
try
{
return(ChooseRandom(clusterMap.GetNodeGroup(localMachine.GetNetworkLocation()), excludedNodes
, blocksize, maxNodesPerRack, results, avoidStaleNodes, storageTypes));
}
catch (BlockPlacementPolicy.NotEnoughReplicasException)
{
DatanodeDescriptor newLocal = SecondNode(localMachine, results);
if (newLocal != null)
{
try
{
return(ChooseRandom(clusterMap.GetNodeGroup(newLocal.GetNetworkLocation()), excludedNodes
, blocksize, maxNodesPerRack, results, avoidStaleNodes, storageTypes));
}
catch (BlockPlacementPolicy.NotEnoughReplicasException)
{
//otherwise randomly choose one from the network
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
}
else
{
//otherwise randomly choose one from the network
return(ChooseRandom(NodeBase.Root, excludedNodes, blocksize, maxNodesPerRack, results
, avoidStaleNodes, storageTypes));
}
}
}
/// <summary><inheritDoc/></summary>
/// <exception cref="Org.Apache.Hadoop.Hdfs.Server.Blockmanagement.BlockPlacementPolicy.NotEnoughReplicasException
/// "/>
protected internal override void ChooseRemoteRack(int numOfReplicas, DatanodeDescriptor
localMachine, ICollection <Node> excludedNodes, long blocksize, int maxReplicasPerRack
, IList <DatanodeStorageInfo> results, bool avoidStaleNodes, EnumMap <StorageType,
int> storageTypes)
{
int oldNumOfReplicas = results.Count;
string rackLocation = NetworkTopology.GetFirstHalf(localMachine.GetNetworkLocation
());
try
{
// randomly choose from remote racks
ChooseRandom(numOfReplicas, "~" + rackLocation, excludedNodes, blocksize, maxReplicasPerRack
, results, avoidStaleNodes, storageTypes);
}
catch (BlockPlacementPolicy.NotEnoughReplicasException)
{
// fall back to the local rack
ChooseRandom(numOfReplicas - (results.Count - oldNumOfReplicas), rackLocation, excludedNodes
, blocksize, maxReplicasPerRack, results, avoidStaleNodes, storageTypes);
}
}
/// <returns>
/// the number of racks over which a given block is replicated
/// decommissioning/decommissioned nodes are not counted. corrupt replicas
/// are also ignored
/// </returns>
private static int GetNumberOfRacks(BlockManager blockManager, Block b)
{
ICollection <string> rackSet = new HashSet <string>(0);
ICollection <DatanodeDescriptor> corruptNodes = GetCorruptReplicas(blockManager).GetNodes
(b);
foreach (DatanodeStorageInfo storage in blockManager.blocksMap.GetStorages(b))
{
DatanodeDescriptor cur = storage.GetDatanodeDescriptor();
if (!cur.IsDecommissionInProgress() && !cur.IsDecommissioned())
{
if ((corruptNodes == null) || !corruptNodes.Contains(cur))
{
string rackName = cur.GetNetworkLocation();
if (!rackSet.Contains(rackName))
{
rackSet.AddItem(rackName);
}
}
}
}
return(rackSet.Count);
}
/// <summary>Scan the targets list: all targets should be on different NodeGroups.</summary>
/// <remarks>
/// Scan the targets list: all targets should be on different NodeGroups.
/// Return false if two targets are found on the same NodeGroup.
/// </remarks>
private static bool CheckTargetsOnDifferentNodeGroup(DatanodeStorageInfo[] targets
)
{
if (targets.Length == 0)
{
return(true);
}
ICollection <string> targetSet = new HashSet <string>();
foreach (DatanodeStorageInfo storage in targets)
{
DatanodeDescriptor node = storage.GetDatanodeDescriptor();
string nodeGroup = NetworkTopology.GetLastHalf(node.GetNetworkLocation());
if (targetSet.Contains(nodeGroup))
{
return(false);
}
else
{
targetSet.AddItem(nodeGroup);
}
}
return(true);
}