{"record":{"id":"45ec34e191a8d8b2","repo":"apache/hadoop","slug":"not-a-supported-codec","errorCode":null,"errorMessage":"Not a supported codec: {}","messagePattern":"Not a supported codec: (.+?)","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageCompression.java","lineNumber":103,"sourceCode":"\n    String codecClassName = conf.get(\n      DFSConfigKeys.DFS_IMAGE_COMPRESSION_CODEC_KEY,\n      DFSConfigKeys.DFS_IMAGE_COMPRESSION_CODEC_DEFAULT);\n    return createCompression(conf, codecClassName);\n  }\n\n  /**\n   * Create a compression instance using the codec specified by\n   * <code>codecClassName</code>\n   */\n  static FSImageCompression createCompression(Configuration conf,\n                                                      String codecClassName)\n    throws IOException {\n\n    CompressionCodecFactory factory = new CompressionCodecFactory(conf);\n    CompressionCodec codec = factory.getCodecByClassName(codecClassName);\n    if (codec == null) {\n      throw new IOException(\"Not a supported codec: \" + codecClassName);\n    }\n\n    return new FSImageCompression(codec);\n  }\n\n  /**\n   * Create a compression instance based on a header read from an input stream.\n   * @throws IOException if the specified codec is not available or the\n   * underlying IO fails.\n   */\n  static FSImageCompression readCompressionHeader(\n    Configuration conf, DataInput in) throws IOException\n  {\n    boolean isCompressed = in.readBoolean();\n\n    if (!isCompressed) {\n      return createNoopCompression();\n    } else {","sourceCodeStart":85,"sourceCodeEnd":121,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageCompression.java#L85-L121","documentation":"Error \"Not a supported codec: {}\" thrown in apache/hadoop.","triggerScenarios":"Reading or writing a compressed fsimage with a codec name that is not supported by FSImageCompression.","commonSituations":"See trigger scenarios.","solutions":["Use a supported compression codec for fsimage (e.g. org.apache.hadoop.io.compress.DefaultCodec).","Ensure the codec class is on the NameNode classpath."],"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"}