How to use

getDataNodeByHostName

method

in

org.apache.hadoop.hdfs.server.blockmanagement.Host2NodesMap

/**
 * Add all nodes from a dependent nodes list to excludedNodes.
 * @return number of new excluded nodes
 */
private int addDependentNodesToExcludedNodes(DatanodeDescriptor chosenNode,
  Set<Node> excludedNodes) {
 if (this.host2datanodeMap == null) {
  return 0;
 }
 int countOfExcludedNodes = 0;
 for(String hostname : chosenNode.getDependentHostNames()) {
  DatanodeDescriptor node =
    this.host2datanodeMap.getDataNodeByHostName(hostname);
  if(node!=null) {
   if (excludedNodes.add(node)) {
    countOfExcludedNodes++;
   }
  } else {
   LOG.warn("Not able to find datanode " + hostname
     + " which has dependency with datanode "
     + chosenNode.getHostName());
  }
 }
 
 return countOfExcludedNodes;
}

/**
 * Add all nodes from a dependent nodes list to excludedNodes.
 * @return number of new excluded nodes
 */
private int addDependentNodesToExcludedNodes(DatanodeDescriptor chosenNode,
  Set<Node> excludedNodes) {
 if (this.host2datanodeMap == null) {
  return 0;
 }
 int countOfExcludedNodes = 0;
 for(String hostname : chosenNode.getDependentHostNames()) {
  DatanodeDescriptor node =
    this.host2datanodeMap.getDataNodeByHostName(hostname);
  if(node!=null) {
   if (excludedNodes.add(node)) {
    countOfExcludedNodes++;
   }
  } else {
   LOG.warn("Not able to find datanode " + hostname
     + " which has dependency with datanode "
     + chosenNode.getHostName());
  }
 }
 
 return countOfExcludedNodes;
}

/**
 * Add all nodes from a dependent nodes list to excludedNodes.
 * @return number of new excluded nodes
 */
private int addDependentNodesToExcludedNodes(DatanodeDescriptor chosenNode,
  Set<Node> excludedNodes) {
 if (this.host2datanodeMap == null) {
  return 0;
 }
 int countOfExcludedNodes = 0;
 for(String hostname : chosenNode.getDependentHostNames()) {
  DatanodeDescriptor node =
    this.host2datanodeMap.getDataNodeByHostName(hostname);
  if(node!=null) {
   if (excludedNodes.add(node)) {
    countOfExcludedNodes++;
   }
  } else {
   LOG.warn("Not able to find datanode " + hostname
     + " which has dependency with datanode "
     + chosenNode.getHostName());
  }
 }
 
 return countOfExcludedNodes;
}