apache/hadoop · error · IOException

No nodetype for {ident}

Error message

No nodetype for {ident}

What it means

Error "No nodetype for {ident}" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/join/Parser.java:208

    }
  }

@SuppressWarnings("unchecked")
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract static class Node extends ComposableInputFormat {
    /**
     * Return the node type registered for the particular identifier.
     * By default, this is a CNode for any composite node and a WNode
     * for "wrapped" nodes. User nodes will likely be composite
     * nodes.
     * @see #addIdentifier(java.lang.String, java.lang.Class[], java.lang.Class, java.lang.Class)
     * @see CompositeInputFormat#setFormat(org.apache.hadoop.mapred.JobConf)
     */
    static Node forIdent(String ident) throws IOException {
      try {
        if (!nodeCstrMap.containsKey(ident)) {
          throw new IOException("No nodetype for " + ident);
        }
        return nodeCstrMap.get(ident).newInstance(ident);
      } catch (IllegalAccessException e) {
        throw new IOException(e);
      } catch (InstantiationException e) {
        throw new IOException(e);
      } catch (InvocationTargetException e) {
        throw new IOException(e);
      }
    }

    private static final Class<?>[] ncstrSig = { String.class };
    private static final
        Map<String,Constructor<? extends Node>> nodeCstrMap =
        new HashMap<String,Constructor<? extends Node>>();
    protected static final Map<String,Constructor<? extends 
        ComposableRecordReader>> rrCstrMap =
        new HashMap<String,Constructor<? extends ComposableRecordReader>>();

View on GitHub (pinned to 2add963021)

Solutions

1. Define the identifier before referencing it: each stream/node name in the join expression must be introduced with its InputFormat and path first.
2. Check for typos in {ident} within the composite join expression.

When it happens

Trigger: Thrown by Parser.CNode when evaluating the join expression finds an identifier with no associated stream/node definition. Define every identifier used in the join expression as an input stream before the join operator references it.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/38f884b136b69e8b. Report an issue: GitHub.