{"record":{"id":"e071cffc7c6435f2","repo":"apache/hadoop","slug":"exception-while-contacting-value-generator","errorCode":null,"errorMessage":"Exception while contacting value generator ","messagePattern":"Exception while contacting value generator ","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/ValueQueue.java","lineNumber":408,"sourceCode":"            numToFill = num - ekvs.size();\n            break;\n          }\n          // Synchronous fill if not enough values found\n          if (numToFill > 0) {\n            refiller.fillQueueForKey(keyName, ekvs, numToFill);\n          }\n\n          break;\n        } else {\n          ekvs.add(val);\n        }\n      }\n      // Schedule a refill task in case queue has gone below the watermark\n      if (keyQueue.size() < (int) (lowWatermark * numValues)) {\n        submitRefillTask(keyName, keyQueue);\n      }\n    } catch (Exception e) {\n      throw new IOException(\"Exception while contacting value generator \", e);\n    }\n    return ekvs;\n  }\n\n  private void submitRefillTask(final String keyName,\n      final Queue<E> keyQueue) throws InterruptedException {\n    if (!executorThreadsStarted) {\n      synchronized (this) {\n        if (!executorThreadsStarted) {\n          // To ensure all requests are first queued, make coreThreads =\n          // maxThreads\n          // and pre-start all the Core Threads.\n          executor.prestartAllCoreThreads();\n          executorThreadsStarted = true;\n        }\n      }\n    }\n    // The submit/execute method of the ThreadPoolExecutor is bypassed and","sourceCodeStart":390,"sourceCodeEnd":426,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/ValueQueue.java#L390-L426","documentation":"Error \"Exception while contacting value generator \" thrown in apache/hadoop.","triggerScenarios":"Raised at runtime when the documented precondition or configuration requirement for this operation is violated.","commonSituations":"Misconfigured or missing property, invalid user input, or calling the API before its prerequisites are met.","solutions":["The background refill thread could not contact the KMS value generator; check KMS availability and credentials."],"exampleFix":"Check KMS server health and auth for the EEK operations.","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"}