apache/hadoop · error · RuntimeException

Version mismatch! Expected {} got {}

Error message

Version mismatch! Expected {} got {}

What it means

Error "Version mismatch! Expected {} got {}" thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-rumen/src/main/java/org/apache/hadoop/tools/rumen/state/StatePool.java:311

  }
  
  /**
   * Getters and setters for JSON serialization
   */
  
  /**
   * To be invoked only by the Jackson JSON serializer.
   */
  public long getVersion() {
    return VERSION;
  }
  
  /**
   * To be invoked only by the Jackson JSON deserializer.
   */
  public void setVersion(long version) {
    if (version != VERSION) {
      throw new RuntimeException("Version mismatch! Expected " + VERSION 
                                 + " got " + version);
    }
  }
  
  /**
   * To be invoked only by the Jackson JSON serializer.
   */
  public HashMap<String, StatePair> getStates() {
    return pool;
  }
  
  /**
   * To be invoked only by the Jackson JSON deserializer.
   */
  public void setStates(HashMap<String, StatePair> states) {
    if (pool.size() > 0) {
      throw new RuntimeException("Pool not empty!");
    }

View on GitHub (pinned to 2add963021)

Solutions

1. Regenerate the persisted state with the current version, or restore using matching code and state versions.

When it happens

Trigger: A persisted state file was written by a different version of the state format than the current code expects.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/8f0b4d6e22e96a3c. Report an issue: GitHub.