apache/hadoop · error · HdfsCompatIllegalArgumentException

suite " + suiteClassName + " suiteName is empty

Error message

suite " + suiteClassName + " suiteName is empty

What it means

Once a custom suite loads, HdfsCompatCommand validates its metadata: getSuiteName() must return a non-null, non-empty name. This error means the class loaded and passed the instanceof check but identifies itself with an empty name, so the tool cannot register, report, or address it.

Solutions

  1. Return a stable non-empty constant from getSuiteName(), matching the name used in -suite and the configuration key
  2. Initialize the name as a compile-time constant rather than runtime state
  3. Rebuild and redeploy the suite jar so the tool loads the fixed class

Example fix

// before
@Override
public String getSuiteName() { return suiteNameField; } // null at runtime
// -> suite ... suiteName is empty

// after
private static final String NAME = "mysuite";
@Override
public String getSuiteName() { return NAME; }
Defensive patterns

Strategy: validation

Validate before calling

HdfsCompatSuite s = (HdfsCompatSuite) Class.forName(cls).getConstructor().newInstance();
String name = s.getSuiteName();
if (name == null || name.isEmpty()) {
  throw new IllegalArgumentException(cls + ": getSuiteName() must not be null/empty");
}

Prevention

When it happens

Trigger: A custom HdfsCompatSuite implementation whose getSuiteName() returns null, "", or a value derived from an uninitialized field or an unset configuration entry.

Common situations: Suite classes copied from a template where the name constant was never filled in; getSuiteName() reading a value that is only populated in certain constructors; name taken from a resource/property that is missing at runtime.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/7c72f8432cf83a67. Report an issue: GitHub.

Appendix: source

Thrown at hadoop-tools/hadoop-compat-bench/src/main/java/org/apache/hadoop/fs/compat/common/HdfsCompatCommand.java:93

    String key = "hadoop.compatibility.suite." + this.suiteName + ".classname";
    final String suiteClassName = conf.get(key, null);
    if ((suiteClassName == null) || suiteClassName.isEmpty()) {
      throw new HdfsCompatIllegalArgumentException(
          "cannot get class name for suite " + this.suiteName +
              ", configuration " + key + " is not properly set.");
    }
    Constructor<?> ctor = suiteClassName.getClass().getConstructor();
    ctor.setAccessible(true);
    Object suiteObj = ctor.newInstance();
    if (suiteObj instanceof HdfsCompatSuite) {
      this.suite = (HdfsCompatSuite) suiteObj;
    } else {
      throw new HdfsCompatIllegalArgumentException(
          "class name " + suiteClassName + " must be an" +
              " implementation of " + HdfsCompatSuite.class.getName());
    }
    if (suite.getSuiteName() == null || suite.getSuiteName().isEmpty()) {
      throw new HdfsCompatIllegalArgumentException(
          "suite " + suiteClassName + " suiteName is empty");
    }
    for (HdfsCompatSuite defaultSuite : defaultSuites.values()) {
      if (suite.getSuiteName().equalsIgnoreCase(defaultSuite.getSuiteName())) {
        throw new HdfsCompatIllegalArgumentException(
            "suite " + suiteClassName + " suiteName" +
                " conflicts with default suite " + defaultSuite.getSuiteName());
      }
    }
    if (!hasApiCase() && !hasShellCase()) {
      throw new HdfsCompatIllegalArgumentException(
          "suite " + suiteClassName + " is empty for both API and SHELL");
    }
  }

  private boolean hasApiCase() {
    return (suite.getApiCases() != null) &&
        (suite.getApiCases().length > 0);

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