apache/hadoop · error · IllegalArgumentException

Compression codec {name} was not found.

Error message

Compression codec {name} was not found.

What it means

Error "Compression codec {name} was not found." thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobConf.java:815

  }
  
  /**
   * Get the {@link CompressionCodec} for compressing the map outputs.
   * 
   * @param defaultValue the {@link CompressionCodec} to return if not set
   * @return the {@link CompressionCodec} class that should be used to compress the 
   *         map outputs.
   * @throws IllegalArgumentException if the class was specified, but not found
   */
  public Class<? extends CompressionCodec> 
  getMapOutputCompressorClass(Class<? extends CompressionCodec> defaultValue) {
    Class<? extends CompressionCodec> codecClass = defaultValue;
    String name = get(JobContext.MAP_OUTPUT_COMPRESS_CODEC);
    if (name != null) {
      try {
        codecClass = getClassByName(name).asSubclass(CompressionCodec.class);
      } catch (ClassNotFoundException e) {
        throw new IllegalArgumentException("Compression codec " + name + 
                                           " was not found.", e);
      }
    }
    return codecClass;
  }
  
  /**
   * Get the key class for the map output data. If it is not set, use the
   * (final) output key class. This allows the map output key class to be
   * different than the final output key class.
   *  
   * @return the map output key class.
   */
  public Class<?> getMapOutputKeyClass() {
    Class<?> retv = getClass(JobContext.MAP_OUTPUT_KEY_CLASS, null, Object.class);
    if (retv == null) {
      retv = getOutputKeyClass();
    }

View on GitHub (pinned to 2add963021)

Solutions

1. Set the compression codec property to a class available on the classpath (e.g. org.apache.hadoop.io.compress.GzipCodec) or add the jar containing the codec.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobConf.java:815 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/65bc4ba743599efd. Report an issue: GitHub.