{"record":{"id":"ce206497d87e0b0f","repo":"apache/hadoop","slug":"input-iterator-not-markable","errorCode":null,"errorMessage":"Input Iterator not markable","messagePattern":"Input Iterator not markable","errorType":"validation","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MarkableIterator.java","lineNumber":45,"sourceCode":"/**\n * <code>MarkableIterator</code> is a wrapper iterator class that \n * implements the {@link MarkableIteratorInterface}.\n * \n */\n@InterfaceAudience.Public\n@InterfaceStability.Evolving\npublic class MarkableIterator<VALUE> \n  implements MarkableIteratorInterface<VALUE> {\n\n  MarkableIteratorInterface<VALUE> baseIterator;\n\n  /**\n   * Create a new iterator layered on the input iterator\n   * @param itr underlying iterator that implements MarkableIteratorInterface\n   */\n  public MarkableIterator(Iterator<VALUE> itr)  {\n    if (!(itr instanceof MarkableIteratorInterface)) {\n      throw new IllegalArgumentException(\"Input Iterator not markable\");\n    }\n    baseIterator = (MarkableIteratorInterface<VALUE>) itr;\n  }\n\n  @Override\n  public void mark() throws IOException {\n    baseIterator.mark();\n  }\n\n  @Override\n  public void reset() throws IOException {\n    baseIterator.reset();\n  }\n\n  @Override\n  public void clearMark() throws IOException {\n    baseIterator.clearMark();\n  }","sourceCodeStart":27,"sourceCodeEnd":63,"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/MarkableIterator.java#L27-L63","documentation":"Error \"Input Iterator not markable\" thrown in apache/hadoop.","triggerScenarios":"Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MarkableIterator.java:45 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["The underlying iterator does not support mark/reset; wrap the input in a markable iterator or avoid operations requiring reset."],"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"}