pentaho/pentaho-kettle · error · KettleException

GroupByMeta.Exception.UnexpectedErrorInReadingStepInfoFromRepository

GroupByMeta.Exception.UnexpectedErrorInReadingStepInfoFromRepository

Error message

GroupByMeta.Exception.UnexpectedErrorInReadingStepInfoFromRepository

What it means

GroupByMeta.readRep wraps any exception from reading the step's attributes out of the repository in this KettleException. The stored GroupBy step definition in the Pentaho repository could not be loaded (attributes unread or a repository call failed).

Solutions

  1. Test the repository connection and retry loading the transformation
  2. Check the wrapped cause to identify which attribute/query failed
  3. Verify repository schema version matches your Pentaho version (run upgrade scripts)
  4. Re-save the GroupBy step in Spoon to rewrite its repository attributes
  5. Restore the step from a known-good transformation export
Defensive patterns

Strategy: try-catch

Validate before calling

// verify repository reachability before loading
if ( !repository.isConnected() || !repository.testConnection() ) {
  throw new IllegalStateException( "Repository unavailable" );
}

Try / catch

try {
  transMeta.loadRep( repository, metaStore, transObjectId, null, null );
} catch ( KettleException e ) {
  if ( e.getMessage().contains( "UnexpectedErrorInReadingStepInfoFromRepository" ) ) {
    log.error( "GroupBy attributes unreadable for step; check repository schema/version", e.getCause() );
  } else { throw e; }
}

Prevention

When it happens

Trigger: loadXML→? no: readRep(rep, id_step) queries step attributes (group_field, aggregate_name, aggregate_type, give_back_row, etc.) and any Repository call or attribute parse throws; caught by the catch block and rethrown.

Common situations: Repository database connectivity issues or schema mismatch; step attributes saved by an incompatible plugin/version; id_step pointing at a deleted or corrupted step record; repository metadata import partially failed.

Understand the failure class

Background: Database query failed: Internal Server Error 500s wrapping SQL, Prisma, and connection failures — what to check first — this error's family across 16 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/b6b6ff7fcf09bb55. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/groupby/GroupByMeta.java:640

        groupField[ i ] = rep.getStepAttributeString( id_step, i, "group_name" );
      }

      boolean hasNumberOfValues = false;
      for ( int i = 0; i < nrvalues; i++ ) {
        aggregateField[ i ] = rep.getStepAttributeString( id_step, i, "aggregate_name" );
        subjectField[ i ] = rep.getStepAttributeString( id_step, i, "aggregate_subject" );
        aggregateType[ i ] = getType( rep.getStepAttributeString( id_step, i, "aggregate_type" ) );

        if ( aggregateType[ i ] == TYPE_GROUP_COUNT_ALL
            || aggregateType[ i ] == TYPE_GROUP_COUNT_DISTINCT || aggregateType[ i ] == TYPE_GROUP_COUNT_ANY ) {
          hasNumberOfValues = true;
        }
        valueField[ i ] = rep.getStepAttributeString( id_step, i, "aggregate_value_field" );
      }

      alwaysGivingBackOneRow = rep.getStepAttributeBoolean( id_step, 0, "give_back_row", hasNumberOfValues );
    } catch ( Exception e ) {
      throw new KettleException( BaseMessages.getString(
        PKG, "GroupByMeta.Exception.UnexpectedErrorInReadingStepInfoFromRepository" ), e );
    }
  }

  @Override
  public void saveRep( Repository rep, IMetaStore metaStore, ObjectId id_transformation, ObjectId id_step )
    throws KettleException {
    try {
      rep.saveStepAttribute( id_transformation, id_step, "all_rows", passAllRows );
      rep.saveStepAttribute( id_transformation, id_step, "ignore_aggregate", aggregateIgnored );
      rep.saveStepAttribute( id_transformation, id_step, "field_ignore", aggregateIgnoredField );
      rep.saveStepAttribute( id_transformation, id_step, "directory", directory );
      rep.saveStepAttribute( id_transformation, id_step, "prefix", prefix );
      rep.saveStepAttribute( id_transformation, id_step, "add_linenr", addingLineNrInGroup );
      rep.saveStepAttribute( id_transformation, id_step, "linenr_fieldname", lineNrInGroupField );
      rep.saveStepAttribute( id_transformation, id_step, "give_back_row", alwaysGivingBackOneRow );

      for ( int i = 0; i < groupField.length; i++ ) {

View on GitHub (pinned to f3058517a1)