apache/hadoop · error · IOException

FS image is being downloaded from another NN

Error message

FS image is being downloaded from another NN

What it means

Error "FS image is being downloaded from another NN" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImage.java:1204

      removeFromCheckpointing(imageTxId);
    }
    //Update NameDirSize Metric
    getStorage().updateNameDirSize();

    if (exitAfterSave.get()) {
      LOG.error("NameNode process will exit now... The saved FsImage " +
          nnf + " is potentially corrupted.");
      ExitUtil.terminate(-1);
    }
  }

  /**
   * @see #saveFSImageInAllDirs(FSNamesystem, NameNodeFile, long, Canceler)
   */
  protected synchronized void saveFSImageInAllDirs(FSNamesystem source, long txid)
      throws IOException {
    if (!addToCheckpointing(txid)) {
      throw new IOException(("FS image is being downloaded from another NN"));
    }
    try {
      saveFSImageInAllDirs(source, NameNodeFile.IMAGE, txid, null);
    } finally {
      removeFromCheckpointing(txid);
    }
  }

  public boolean addToCheckpointing(long txid) {
    return currentlyCheckpointing.add(txid);
  }

  public void removeFromCheckpointing(long txid) {
    currentlyCheckpointing.remove(txid);
  }

  void save(FSNamesystem src, File dst) throws IOException {
    final long txid = getCorrectLastAppliedOrWrittenTxId();

View on GitHub (pinned to 2add963021)

Solutions

1. Wait for the ongoing image download to finish; avoid concurrent bootstrap/save operations.

When it happens

Trigger: A storage directory operation is rejected because an fsimage download from another NameNode is in progress.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/844dde757d8dc08e. Report an issue: GitHub.