pentaho/pentaho-kettle · error · KettleException

MappingInputMeta.Exception.UnexpectedErrorInReadingStepInfo

MappingInputMeta.Exception.UnexpectedErrorInReadingStepInfo

Error message

MappingInputMeta.Exception.UnexpectedErrorInReadingStepInfo

What it means

MappingInputMeta.readRep() wraps any exception thrown while reading the Mapping Input step's attributes (field names, types, lengths, precisions, select_unspecified flag) from the Kettle repository into a KettleException with this message key. It signals that the stored step definition could not be loaded, typically due to repository connectivity issues or corrupt/missing metadata. The original exception is chained as the cause.

Solutions

1. Verify the repository connection is alive and re-connect, then retry loading the transformation.
2. Check the chained cause exception for the underlying repository/database error and fix it (permissions, missing rows, network).
3. Confirm id_step refers to an existing step in R_STEP_ATTRIBUTE; if the step row is corrupt, re-create the step in Spoon and re-save the transformation.
4. If caused by a version mismatch, upgrade/repair the repository tables and re-export the transformation.

Example fix

// before: loading directly, connection may be stale
meta.readRep(repository, metastore, transObjectId, stepObjectId);

// after: ensure a live repository first
if (repository == null || !repository.isConnected()) {
  repository.connect(user, password);
}
try {
  meta.readRep(repository, metastore, transObjectId, stepObjectId);
} catch (KettleException e) {
  logError("Failed to read MappingInput step metadata: " + e.getCause(), e);
  throw e;
}

if (repository == null || !repository.isConnected()) {
  repository.connect(user, password);
}
// confirm the step exists before readRep
if (repository.getStepAttributeCount(id_step) <= 0) {
  throw new IllegalStateException("Step attributes missing for id_step=" + id_step);
}

boolean isReadable(Repository rep, ObjectId idStep) {
  return rep != null && rep.isConnected() && idStep != null;
}

try {
  meta.readRep(repository, metastore, transObjectId, stepObjectId);
} catch (KettleException e) {
  logError("MappingInput metadata read failed: " + e.getCause(), e);
  throw new RuntimeException("Repository read failed; check connection and step metadata", e);
}

When it happens

Trigger: Calling readRep() on a MappingInputMeta when Repository.getStepAttributeInteger/getStepAttributeBoolean throws — e.g. repository connection dropped mid-read, id_step points to a deleted/nonexistent step row, or a stored attribute has an unexpected value that fails conversion.

Common situations: Opening a transformation from a repository where the step metadata was manually edited or corrupted; stale repository connections after a database restart; reading transformations created in a much older Pentaho version with incompatible stored attributes; permission problems on the repository database.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• CubeInputMeta.Exception.UnableToSaveStepInfo
• CubeOutputMeta.Exception.UnableToSaveStepInfo
• CubeOutputMeta.Exception.UnexpectedErrorInReadingStepInfo
• DelayMeta.Exception.UnexpectedErrorReadingStepInfo
• DelayMeta.Exception.UnexpectedErrorSavingStepInfo

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/4592355d50cae65d. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/mappinginput/MappingInputMeta.java:353

  }

  public void readRep( Repository rep, IMetaStore metaStore, ObjectId id_step, List<DatabaseMeta> databases )
    throws KettleException {
    try {
      int nrfields = rep.countNrStepAttributes( id_step, "field_name" );

      allocate( nrfields );

      for ( int i = 0; i < nrfields; i++ ) {
        fieldName[ i ] = rep.getStepAttributeString( id_step, i, "field_name" );
        fieldType[ i ] = ValueMetaFactory.getIdForValueMeta( rep.getStepAttributeString( id_step, i, "field_type" ) );
        fieldLength[ i ] = (int) rep.getStepAttributeInteger( id_step, i, "field_length" );
        fieldPrecision[ i ] = (int) rep.getStepAttributeInteger( id_step, i, "field_precision" );
      }

      selectingAndSortingUnspecifiedFields = rep.getStepAttributeBoolean( id_step, "select_unspecified" );
    } catch ( Exception e ) {
      throw new KettleException( BaseMessages.getString(
        PKG, "MappingInputMeta.Exception.UnexpectedErrorInReadingStepInfo" ), e );
    }
  }

  public void saveRep( Repository rep, IMetaStore metaStore, ObjectId id_transformation, ObjectId id_step )
    throws KettleException {
    try {
      for ( int i = 0; i < fieldName.length; i++ ) {
        if ( fieldName[ i ] != null && fieldName[ i ].length() != 0 ) {
          rep.saveStepAttribute( id_transformation, id_step, i, "field_name", fieldName[ i ] );
          rep.saveStepAttribute( id_transformation, id_step, i, "field_type",
            ValueMetaFactory.getValueMetaName( fieldType[ i ] ) );
          rep.saveStepAttribute( id_transformation, id_step, i, "field_length", fieldLength[ i ] );
          rep.saveStepAttribute( id_transformation, id_step, i, "field_precision", fieldPrecision[ i ] );
        }
      }

      rep.saveStepAttribute(

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