apache/hadoop · error · IllegalArgumentException

Network location name contains /: {}

Error message

Network location name contains /: {}

What it means

NodeBase.set(name, location) validates that a node's NAME contains no '/' (PATH_SEPARATOR_STR). The name identifies the leaf itself (typically host:port); all hierarchy lives in the location string. A slash inside the name would corrupt path parsing, so IllegalArgumentException is thrown at construction.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NodeBase.java:90

   * @param name this node's name (can be null, must not contain {@link #PATH_SEPARATOR})
   * @param location this node's location 
   * @param parent this node's parent node
   * @param level this node's level in the tree
   */
  public NodeBase(String name, String location, Node parent, int level) {
    set(name, normalize(location));
    this.parent = parent;
    this.level = level;
  }

  /**
   * set this node's name and location
   * @param name the (nullable) name -which cannot contain the {@link #PATH_SEPARATOR}
   * @param location the location
   */
  private void set(String name, String location) {
    if (name != null && name.contains(PATH_SEPARATOR_STR))
      throw new IllegalArgumentException(
                                         "Network location name contains /: "+name);
    this.name = (name==null)?"":name;
    this.location = location;      
  }
  
  /** @return this node's name */
  @Override
  public String getName() { return name; }
  
  /** @return this node's network location */
  @Override
  public String getNetworkLocation() { return location; }
  
  /** Set this node's network location
   * @param location the location
   */
  @Override
  public void setNetworkLocation(String location) { this.location = location; }

View on GitHub (pinned to 2add963021)

Solutions

1. Keep the name slash-free: pass only the host identifier or host:port
2. When recreating a node from a path, split it: name = last component, location = the remaining prefix
3. Validate with name.contains("/") before constructing

Example fix

// before
new NodeBase("/rack1/host1", "/rack1"); // name contains '/'

// after
new NodeBase("host1", "/rack1");

if (name != null && name.contains("/")) {
  throw new IllegalArgumentException("Node name must not contain '/': " + name);
}
Node n = new NodeBase(name, location);

static boolean isValidNodeName(String name) {
  return name != null && !name.contains("/");
}

When it happens

Trigger: new NodeBase("host/rack", "/rack") or any set(...) call where the name embeds a '/'. Common: feeding a full path '/rack/host' back in as the name when reconstructing nodes.

Common situations: Round-tripping NodeBase.getPath(node) output and passing it as the name to a new NodeBase; test fixtures that conflate name and location; parsing datanode names that contain escaped slashes.

Related errors

• Network Locationpath doesn't start with /: {}
• Not allow to add an inner node: {}
• Not allow to remove an inner node: {}
• Network Location path does not start with /: {}
• getXAttrs on path `{}' is not within a mount point

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/b84abc5e3b12b0c2. Report an issue: GitHub.