{"record":{"id":"01328a7619da7a76","repo":"apache/hadoop","slug":"could-not-launch-job","errorCode":null,"errorMessage":"Could not launch job","messagePattern":"Could not launch job","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/JobSubmitter.java","lineNumber":257,"sourceCode":"      // Set reservation info if it exists\n      ReservationId reservationId = job.getReservationId();\n      if (reservationId != null) {\n        conf.set(MRJobConfig.RESERVATION_ID, reservationId.toString());\n      }\n\n      // Write job file to submit dir\n      writeConf(conf, submitJobFile);\n      \n      //\n      // Now, actually submit the job (using the submit name)\n      //\n      printTokens(jobId, job.getCredentials());\n      status = submitClient.submitJob(\n          jobId, submitJobDir.toString(), job.getCredentials());\n      if (status != null) {\n        return status;\n      } else {\n        throw new IOException(\"Could not launch job\");\n      }\n    } finally {\n      if (status == null) {\n        LOG.info(\"Cleaning up the staging area \" + submitJobDir);\n        if (jtFs != null && submitJobDir != null)\n          jtFs.delete(submitJobDir, true);\n\n      }\n    }\n  }\n  \n  private void checkSpecs(Job job) throws ClassNotFoundException, \n      InterruptedException, IOException {\n    JobConf jConf = (JobConf)job.getConfiguration();\n    // Check the output specification\n    if (jConf.getNumReduceTasks() == 0 ? \n        jConf.getUseNewMapper() : jConf.getUseNewReducer()) {\n      org.apache.hadoop.mapreduce.OutputFormat<?, ?> output =","sourceCodeStart":239,"sourceCodeEnd":275,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/JobSubmitter.java#L239-L275","documentation":"Error \"Could not launch job\" thrown in apache/hadoop.","triggerScenarios":"Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/JobSubmitter.java:257 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Examine the wrapped exception and cluster ResourceManager logs for the launch failure cause, fix it, and resubmit."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-22T20:17:22.307Z"}