apache/hadoop · error · RuntimeException

Simulated job's configuration parameter '{}' got scaled to a

Error message

Simulated job's configuration parameter '{}' got scaled to a value '{}' which exceeds the upper limit of '{}' defined for the simulated cluster by the key '{}'. To disable High-Ram feature emulation, set 'gridmix.highram-emulation.enable' to 'false'.

What it means

Error "Simulated job's configuration parameter '{}' got scaled to a value '{}' which exceeds the upper limit of '{}' defined for the simulated cluster by the key '{}'. To disable High-Ram feature emulation, set 'gridmix.highram-emulation.enable' to 'false'." thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-gridmix/src/main/java/org/apache/hadoop/mapred/gridmix/GridmixJob.java:282

  // valid
  @SuppressWarnings("deprecation")
  private static boolean checkMemoryUpperLimits(String jobKey, String limitKey,  
                                                Configuration conf, 
                                                boolean convertLimitToMB) {
    if (conf.get(limitKey) != null) {
      long limit = conf.getLong(limitKey, JobConf.DISABLED_MEMORY_LIMIT);
      // scale only if the max memory limit is set.
      if (limit >= 0) {
        if (convertLimitToMB) {
          limit /= (1024 * 1024); //Converting to MB
        }
        
        long scaledConfigValue = 
               conf.getLong(jobKey, JobConf.DISABLED_MEMORY_LIMIT);
        
        // check now
        if (scaledConfigValue > limit) {
          throw new RuntimeException("Simulated job's configuration" 
              + " parameter '" + jobKey + "' got scaled to a value '" 
              + scaledConfigValue + "' which exceeds the upper limit of '" 
              + limit + "' defined for the simulated cluster by the key '" 
              + limitKey + "'. To disable High-Ram feature emulation, set '" 
              + GRIDMIX_HIGHRAM_EMULATION_ENABLE + "' to 'false'.");
        }
        return true;
      }
    }
    return false;
  }
  
  // Check if the parameter scaling does not exceed the cluster limits.
  @SuppressWarnings("deprecation")
  private static void validateTaskMemoryLimits(Configuration conf, 
                        String jobKey, String clusterMaxKey) {
    if (!checkMemoryUpperLimits(jobKey, 
        JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY, conf, true)) {

View on GitHub (pinned to 2add963021)

Solutions

1. Lower the scaled memory parameter in the trace, raise the simulated cluster limit, or set gridmix.highram-emulation.enable=false.

When it happens

Trigger: High-Ram emulation scales a job's memory configuration beyond the simulated cluster's configured maximum, so Gridmix refuses to submit the job unless high-ram emulation is disabled.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/9f21f58b4ae23d7c. Report an issue: GitHub.