{"record":{"id":"4fc58951aca684b9","repo":"apache/hadoop","slug":"invalid-missing-generation-bytes","errorCode":null,"errorMessage":"Invalid/missing generation bytes: {}","messagePattern":"Invalid/missing generation bytes: (.+?)","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"hadoop-tools/hadoop-gridmix/src/main/java/org/apache/hadoop/mapred/gridmix/GenerateData.java","lineNumber":245,"sourceCode":"        r.nextBytes(val.getBytes());\n        val.setSize((int)Math.min(val.getLength(), bytes));\n        context.write(key, val);\n      }\n    }\n\n  }\n\n  static class GenDataFormat extends InputFormat<NullWritable,LongWritable> {\n\n    @Override\n    public List<InputSplit> getSplits(JobContext jobCtxt) throws IOException {\n      final JobClient client =\n        new JobClient(new JobConf(jobCtxt.getConfiguration()));\n      ClusterStatus stat = client.getClusterStatus(true);\n      final long toGen =\n        jobCtxt.getConfiguration().getLong(GRIDMIX_GEN_BYTES, -1);\n      if (toGen < 0) {\n        throw new IOException(\"Invalid/missing generation bytes: \" + toGen);\n      }\n      final int nTrackers = stat.getTaskTrackers();\n      final long bytesPerTracker = toGen / nTrackers;\n      final ArrayList<InputSplit> splits = new ArrayList<InputSplit>(nTrackers);\n      final Pattern trackerPattern = Pattern.compile(\"tracker_([^:]*):.*\");\n      final Matcher m = trackerPattern.matcher(\"\");\n      for (String tracker : stat.getActiveTrackerNames()) {\n        m.reset(tracker);\n        if (!m.find()) {\n          System.err.println(\"Skipping node: \" + tracker);\n          continue;\n        }\n        final String name = m.group(1);\n        splits.add(new GenSplit(bytesPerTracker, new String[] { name }));\n      }\n      return splits;\n    }\n","sourceCodeStart":227,"sourceCodeEnd":263,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-tools/hadoop-gridmix/src/main/java/org/apache/hadoop/mapred/gridmix/GenerateData.java#L227-L263","documentation":"Error \"Invalid/missing generation bytes: {}\" thrown in apache/hadoop.","triggerScenarios":"The gridmix.generate.file.size (or related generation byte count) configured for Gridmix data generation is missing or invalid.","commonSituations":"See trigger scenarios.","solutions":["Pass a valid positive byte count via -generate <size> (e.g. -generate 100GB)."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-22T20:17:22.307Z"}