apache/hadoop · error · UnsupportedOperationException

Operation "{}" is not supported

Error message

Operation "{}" is not supported

What it means

Error "Operation "{}" is not supported" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcServer.java:837

   * operation.
   *
   * @param op Category of the operation to check.
   * @param supported If the operation is supported or not. If not, it will
   *                  throw an UnsupportedOperationException.
   * @throws StandbyException If the Router is in safe mode and cannot serve
   *                           client requests.
   * @throws UnsupportedOperationException If the operation is not supported.
   */
  public void checkOperation(OperationCategory op, boolean supported)
      throws StandbyException, UnsupportedOperationException {
    checkOperation(op);

    if (!supported) {
      if (rpcMonitor != null) {
        rpcMonitor.proxyOpNotImplemented();
      }
      String methodName = getMethodName();
      throw new UnsupportedOperationException(
          "Operation \"" + methodName + "\" is not supported");
    }
  }

  /**
   * Check if the Router is in safe mode. We should only see READ, WRITE, and
   * UNCHECKED. This function should be called by all ClientProtocol functions.
   *
   * @param op Category of the operation to check.
   * @throws StandbyException If the Router is in safe mode and cannot serve
   *                           client requests.
   */
  public void checkOperation(OperationCategory op)
      throws StandbyException {
    // Log the function we are currently calling.
    if (rpcMonitor != null) {
      rpcMonitor.startOp();
    }

View on GitHub (pinned to 2add963021)

Solutions

1. Use an operation the Router supports; consult the RouterClientProtocol surface for the supported set.
2. Issue the unsupported call directly against the target namenode instead of the Router.
3. Upgrade Hadoop if the operation is supported by Routers in a newer release.

When it happens

Trigger: Client invoked an RPC method that RouterRpcServer explicitly does not support.

Common situations: Clients calling advanced/less-common HDFS APIs (e.g. certain snapshot, cache, or erasure-coding ops) through the Router.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/be9ec03fca181b18. Report an issue: GitHub.