{"record":{"id":"72b4eedd05ffdf87","repo":"apache/hadoop","slug":"tried-to-skip-bytes-past-the-limit-at-offset","errorCode":null,"errorMessage":"Tried to skip {} bytes past the limit at offset {}","messagePattern":"Tried to skip (.+?) bytes past the limit at offset (.+?)","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java","lineNumber":1418,"sourceCode":"    @Override\n    public void reset() throws IOException {\n      if (markPos == -1) {\n        throw new IOException(\"Not marked!\");\n      }\n      super.reset();\n      curPos = markPos;\n      markPos = -1;\n    }\n\n    public long getPos() {\n      return curPos;\n    }\n    \n    @Override\n    public long skip(long amt) throws IOException {\n      long extra = (curPos + amt) - limitPos;\n      if (extra > 0) {\n        throw new IOException(\"Tried to skip \" + extra + \" bytes past \" +\n            \"the limit at offset \" + limitPos);\n      }\n      long ret = super.skip(amt);\n      curPos += ret;\n      return ret;\n    }\n  }\n\n  public long getLastAppliedTxId() {\n    return lastAppliedTxId;\n  }\n\n  /**\n   * Creates a Step used for updating startup progress, populated with\n   * information from the given edits.  The step always includes the log's name.\n   * If the log has a known length, then the length is included in the step too.\n   * \n   * @param edits EditLogInputStream to use for populating step","sourceCodeStart":1400,"sourceCodeEnd":1436,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java#L1400-L1436","documentation":"The skip() counterpart of the read limiter in PositionTrackingInputStream: skipping amt bytes would cross the limit that FSEditLogOp.Reader set via setLimit(maxOpSize) before decoding an op. In practice the reader skips the remainder of a frame whose declared length already exceeded the bound, so this marks the same condition as the read variant: garbage or torn data pushing a single op past its size limit.","triggerScenarios":"The op reader skipping past a corrupt op frame whose declared length exceeds maxOpSize during edit log load or scan; torn final segment after a NameNode crash.","commonSituations":"Corrupt segment tails; partial segment copies; misconfigured dfs.namenode.max.op.size.","solutions":["Treat the segment as corrupt: validate with 'hdfs oev' and recover with 'hdfs namenode -recover'","Raise dfs.namenode.max.op.size only when valid ops genuinely exceed the 50MB default","Restore a consistent fsimage plus edits from backup"],"exampleFix":"# before: scan/replay trips the skip limiter on a bad frame\n# IOException: Tried to skip N bytes past the limit at offset L\n\n# after: identify and skip the corrupt tail\nhdfs oev -i <segment> -o /tmp/check.xml -p xml\nhdfs namenode -recover","handlingStrategy":"try-catch","validationCode":"hdfs oev -i <segment> -o /tmp/check.xml -p xml   # validates op sizes and checksums before replay","typeGuard":null,"tryCatchPattern":"try {\n  op = in.readOp();\n} catch (IOException ioe) {          // includes 'Tried to skip ... past the limit'\n  LOG.warn(\"Bad frame at offset \" + in.getPosition(), ioe);\n  in.resync();\n}","preventionTips":["Do not lower dfs.namenode.max.op.size below real op sizes","Verify segment checksums after copying files between hosts"],"tags":["hdfs","namenode","edit-log","corruption","max-op-size","stream-limit"],"backgroundTag":"max-op-size-exceeded","analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-22T20:17:22.307Z"}