{"record":{"id":"d2f449acbbaa45bd","repo":"pentaho/pentaho-kettle","slug":"error-opening-writer-socket-to-remote-step-remotestep","errorCode":null,"errorMessage":"Error opening writer socket to remote step '\" + remoteStep + \"'","messagePattern":"Error opening writer socket to remote step '\" \\+ remoteStep \\+ \"'","errorType":"exception","errorClass":"KettleStepException","httpStatus":null,"severity":"critical","filePath":"engine/src/main/java/org/pentaho/di/trans/step/BaseStep.java","lineNumber":2093,"sourceCode":"            + Const.INTERNAL_VARIABLE_SLAVE_SERVER_NAME + \"' is not defined.\" );\n        }\n      }\n\n      // Start threads: one per remote step to funnel the data through...\n      //\n      for ( RemoteStep remoteStep : remoteOutputSteps ) {\n        try {\n          if ( remoteStep.getTargetSlaveServerName() == null ) {\n            throw new KettleStepException(\n              \"The target slave server name is not defined for remote output step: \" + remoteStep );\n          }\n          BlockingRowSet rowSet = remoteStep.openWriterSocket();\n          if ( log.isDetailed() ) {\n            logDetailed( BaseMessages.getString( PKG, \"BaseStep.Log.OpenedWriterSocketToRemoteStep\", remoteStep ) );\n          }\n          outputRowSets.add( rowSet );\n        } catch ( IOException e ) {\n          throw new KettleStepException( \"Error opening writer socket to remote step '\" + remoteStep + \"'\", e );\n        }\n      }\n    } finally {\n      outputRowSetsLock.writeLock().unlock();\n    }\n    remoteOutputStepsInitialized = true;\n  }\n\n  /**\n   * Safe mode checking.\n   *\n   * @param row the row\n   * @throws KettleRowException the kettle row exception\n   */\n  protected void safeModeChecking( RowMetaInterface row ) throws KettleRowException {\n    if ( row == null ) {\n      return;\n    }","sourceCodeStart":2075,"sourceCodeEnd":2111,"githubUrl":"https://github.com/pentaho/pentaho-kettle/blob/f3058517a153da500bf4551f46d79b91bf8ec552/engine/src/main/java/org/pentaho/di/trans/step/BaseStep.java#L2075-L2111","documentation":"After validating the target slave name, BaseStep calls RemoteStep.openWriterSocket() to open the socket used to stream rows to the remote output step. An IOException is wrapped in a KettleStepException with this message. The step cannot send its output rows to the remote host.","triggerScenarios":"openWriterSocket() throws IOException during remote output initialization — the remote slave's server socket isn't listening, the host/port is wrong, the connection is refused, or the connection drops mid-handshake.","commonSituations":"Slave server not started or crashed; firewall blocking the cluster data ports; wrong port in the cluster schema; network partition between master and slaves; remote step buffers already closed from a prior failed run.","solutions":["Confirm the slave server is running and its data port is listening (telnet/nc to host:port).","Correct host/port settings in the cluster schema for the remote step.","Open firewall rules for Kettle cluster data ports between nodes.","Retry the run after network recovery; catch KettleStepException and inspect the wrapped IOException for the root cause."],"exampleFix":"// before: port mismatch\nremoteStep.setPort(\"8080\"); // slave listens on 8081\n\n// after\nremoteStep.setPort(\"8081\");","handlingStrategy":"retry","validationCode":"// Pre-check writer socket endpoint reachability\ntry (Socket s = new Socket()) {\n  s.connect(new InetSocketAddress(remoteStep.getHostname(), remoteStep.getPort()), 3000);\n} catch (IOException e) {\n  throw new IllegalStateException(\"Writer endpoint unreachable: \" + remoteStep);\n}","typeGuard":null,"tryCatchPattern":"try {\n  trans.execute(null);\n} catch (KettleStepException e) {\n  if (e.getMessage().contains(\"Error opening writer socket\")) {\n    logError(\"Cannot write to remote step: \" + e.getMessage(), e.getCause());\n    // backoff and retry the clustered run\n  } else { throw e; }\n}","preventionTips":["Ensure slave servers are fully started before the master run","Whitelist Kettle data ports in firewalls between nodes","Monitor slave health during clustered executions"],"tags":["network","socket","cluster"],"backgroundTag":"connection-refused","analyzedSha":"f3058517a153da500bf4551f46d79b91bf8ec552","analyzedAt":"2026-09-13T14:04:16.340Z","contentChangedAt":"2026-09-13T14:04:16.340Z","schemaVersion":2},"datasetVersion":"2026-09-20T23:17:15.980Z"}