apache/hadoop · error · IOException

invalid arguments, klass or serializer is null

Error message

invalid arguments, klass or serializer is null

What it means

Error "invalid arguments, klass or serializer is null" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/java/org/apache/hadoop/mapred/nativetask/serde/NativeSerialization.java:62

      throw new IOException("Cannot serialize type " + c.getName() +
                            ", we only accept subclass of Writable");
    }
    final String name = c.getName();
    final Class<?> serializer = map.get(name);

    if (null != serializer) {
      try {
        return (INativeSerializer<Writable>) serializer.newInstance();
      } catch (final Exception e) {
        throw new IOException(e);
      }
    }
    return new DefaultSerializer();
  }

  public void register(String klass, Class<?> serializer) throws IOException {
    if (null == klass || null == serializer) {
      throw new IOException("invalid arguments, klass or serializer is null");
    }

    if (!INativeSerializer.class.isAssignableFrom(serializer)) {
      throw new IOException("Serializer is not assigable from INativeSerializer");
    }

    final Class<?> storedSerializer = map.get(klass);
    if (null == storedSerializer) {
      map.put(klass, serializer);
      return;
    } else {
      if (!storedSerializer.getName().equals(serializer.getName())) {
        throw new IOException("Error! Serializer already registered, existing: " +
                              storedSerializer.getName() + ", new: " +
                              serializer.getName());
      }
    }
  }

View on GitHub (pinned to 2add963021)

Solutions

1. Pass non-null class and serializer to NativeSerialization.register(); check the configuration keys for native serializers are set correctly.
2. Fix the calling code so neither klass nor serializer argument is null.

When it happens

Trigger: Thrown by NativeSerialization.register()/getSerializer() when called with a null class or null serializer argument. Pass a non-null Writable class and a non-null INativeSerializer implementation.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/2e73f44c790f04c8. Report an issue: GitHub.