apache/hadoop · error · ShortCircuitFdsVersionException

Your client is too old to read this block! Its format versi

Error message

Your client is too old to read this block!  Its format version is {}, but the highest format version you can read is {}

What it means

Error "Your client is too old to read this block! Its format version is {}, but the highest format version you can read is {}" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java:2487

  @InterfaceAudience.LimitedPrivate("HDFS")
  static public class ShortCircuitFdsVersionException extends IOException {
    private static final long serialVersionUID = 1L;
    public ShortCircuitFdsVersionException(String msg) {
      super(msg);
    }
  }

  FileInputStream[] requestShortCircuitFdsForRead(final ExtendedBlock blk,
      final Token<BlockTokenIdentifier> token, int maxVersion) 
          throws ShortCircuitFdsUnsupportedException,
            ShortCircuitFdsVersionException, IOException {
    if (fileDescriptorPassingDisabledReason != null) {
      throw new ShortCircuitFdsUnsupportedException(
          fileDescriptorPassingDisabledReason);
    }
    int blkVersion = CURRENT_BLOCK_FORMAT_VERSION;
    if (maxVersion < blkVersion) {
      throw new ShortCircuitFdsVersionException("Your client is too old " +
        "to read this block!  Its format version is " + 
        blkVersion + ", but the highest format version you can read is " +
        maxVersion);
    }
    metrics.incrBlocksGetLocalPathInfo();
    FileInputStream fis[] = new FileInputStream[2];
    
    try {
      checkStorageState("requestShortCircuitFdsForRead");
      fis[0] = (FileInputStream)data.getBlockInputStream(blk, 0);
      fis[1] = DatanodeUtil.getMetaDataInputStream(blk, data);
    } catch (ClassCastException e) {
      LOG.debug("requestShortCircuitFdsForRead failed", e);
      throw new ShortCircuitFdsUnsupportedException("This DataNode's " +
          "FsDatasetSpi does not support short-circuit local reads");
    }
    return fis;
  }

View on GitHub (pinned to 2add963021)

Solutions

1. Upgrade the client to a Hadoop version whose meta format version supports the block metadata version on disk.
2. Or downgrade/rewrite the block metadata to a version the client supports (not typical; upgrading the client is preferred).

When it happens

Trigger: A client using an older metadata format version attempts a short-circuit read of a block whose on-disk meta file uses a newer format.

Common situations: The client library is older than the block's on-disk format version. Upgrade the client to a version supporting the cluster's layout version.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/bd82504843b4853a. Report an issue: GitHub.