What causes "Trans.Exception.UnableToPerformLoggingAtTransEnd" in pentaho/pentaho-kettle?

Check the cause exception for the underlying database error (connection closed, table missing) and fix the log database.

pentaho/pentaho-kettle · error · KettleException

Trans.Exception.UnableToPerformLoggingAtTransEnd

Error message

Trans.Exception.UnableToPerformLoggingAtTransEnd

What it means

Thrown from a TransListener added in Trans.beginProcessing(): when the transformation finishes, endProcessing() and writeStepPerformanceLogRecords(...) write final log/step-performance records; if that raises KettleException it is rethrown as UnableToPerformLoggingAtTransEnd. The transformation itself has already run; only the final logging write-out failed.

Solutions

Check the cause exception for the underlying database error (connection closed, table missing) and fix the log database.
Verify the step performance log table exists with the correct schema; recreate via the Log tab SQL generation.
Enable log table batching/reconnection or use interval logging to reduce long-held connections that get dropped by firewalls.
Recover run results from the transformation log table's earlier rows; the transformation execution itself was unaffected.

Example fix

// before: long transformation, DB connection idle-dropped, final perf record write fails
// after: enable interval logging on the trans log table
Interval in seconds = 30  (Log tab, keeps connection alive and writes periodically)

Defensive patterns

Strategy: try-catch

Validate before calling

// Verify step performance log table connectivity before the run
DatabaseMeta perfDb = logTable.getDatabaseMeta();
if (!new Database(trans, perfDb).checkTableExists("STEP_PERFORMANCE")) {
  log.warn("Step performance log table missing; final perf write will fail");
}

Try / catch

try {
  trans.waitUntilFinished();
} catch (Exception e) {
  Throwable root = e;
  while (root.getCause() != null) root = root.getCause();
  log.error("End-of-run logging failed; transformation result still in trans log table", root);
}

Prevention

Enable interval logging to keep the log connection from idling out on firewalls.
Monitor DB uptime during long transformations.
Set reasonable row limits on step performance logging to avoid huge final writes.

When it happens

Trigger: A TransAdapter.transFinished listener wraps endProcessing() plus writeStepPerformanceLogRecords(..., LogStatus.END) in try/catch(KettleException) and rethrows with key Trans.Exception.UnableToPerformLoggingAtTransEnd; requires step performance logging to be enabled (transPerfMonitors / performance log table configured).

Common situations: Step performance log table connection lost during a long-running transformation; database restarted while the transformation ran; log table full/disk quota exceeded; performance log table schema altered.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/c3e08e276a514a9a. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/Trans.java:2525

              public void transFinished( Trans trans ) {
                timer.cancel();
              }
            } );
          }

          // Add a listener to make sure that the last record is also written when transformation finishes...
          //
          addTransListener( new TransAdapter() {
            @Override
            public void transFinished( Trans trans ) throws KettleException {
              try {
                endProcessing();

                lastWrittenStepPerformanceSequenceNr =
                  writeStepPerformanceLogRecords( lastWrittenStepPerformanceSequenceNr, LogStatus.END );

              } catch ( KettleException e ) {
                throw new KettleException( BaseMessages.getString( PKG,
                  "Trans.Exception.UnableToPerformLoggingAtTransEnd" ), e );
              }
            }
          } );

        }

        // If we need to write out the step logging information, do so at the end of the transformation too...
        //
        StepLogTable stepLogTable = transMeta.getStepLogTable();
        if ( stepLogTable.isDefined() ) {
          addTransListener( new TransAdapter() {
            @Override
            public void transFinished( Trans trans ) throws KettleException {
              try {
                writeStepLogInformation();
              } catch ( KettleException e ) {
                throw new KettleException( BaseMessages.getString( PKG,

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