apache/hadoop · error · RuntimeException

mapreduce.input.sequencefileinputfilter.regexnot set

Error message

mapreduce.input.sequencefileinputfilter.regexnot set

What it means

Error "mapreduce.input.sequencefileinputfilter.regexnot set" 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/input/SequenceFileInputFilter.java:134

     */
    public static void setPattern(Configuration conf, String regex)
        throws PatternSyntaxException {
      try {
        Pattern.compile(regex);
      } catch (PatternSyntaxException e) {
        throw new IllegalArgumentException("Invalid pattern: "+regex);
      }
      conf.set(FILTER_REGEX, regex);
    }
        
    public RegexFilter() { }
        
    /** configure the Filter by checking the configuration
     */
    public void setConf(Configuration conf) {
      String regex = conf.get(FILTER_REGEX);
      if (regex == null)
        throw new RuntimeException(FILTER_REGEX + "not set");
      this.p = Pattern.compile(regex);
      this.conf = conf;
    }


    /** Filtering method
     * If key matches the regex, return true; otherwise return false
     * @see Filter#accept(Object)
     */
    public boolean accept(Object key) {
      return p.matcher(key.toString()).matches();
    }
  }

  /** This class returns a percentage of records
   * The percentage is determined by a filtering frequency <i>f</i> using
   * the criteria record# % f == 0.
   * For example, if the frequency is 10, one out of 10 records is returned.

View on GitHub (pinned to 2add963021)

Solutions

1. Set mapreduce.input.sequencefileinputfilter.regex in the job configuration when using RegexFilter.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/SequenceFileInputFilter.java:134 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/dec030e7ef7d0294. Report an issue: GitHub.