apache/hadoop · error · IllegalArgumentException

Invalid operation {op}

Error message

Invalid operation {op}

What it means

Error "Invalid operation {op}" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/webhdfs/WebHdfsHandler.java:180

    String op = params.op();
    HttpMethod method = req.method();
    if (PutOpParam.Op.CREATE.name().equalsIgnoreCase(op)
      && method == PUT) {
      onCreate(ctx);
    } else if (PostOpParam.Op.APPEND.name().equalsIgnoreCase(op)
      && method == POST) {
      onAppend(ctx);
    } else if (GetOpParam.Op.OPEN.name().equalsIgnoreCase(op)
      && method == GET) {
      onOpen(ctx);
    } else if(GetOpParam.Op.GETFILECHECKSUM.name().equalsIgnoreCase(op)
      && method == GET) {
      onGetFileChecksum(ctx);
    } else if(PutOpParam.Op.CREATE.name().equalsIgnoreCase(op)
        && method == OPTIONS) {
      allowCORSOnCreate(ctx);
    } else {
      throw new IllegalArgumentException("Invalid operation " + op);
    }
  }

  @Override
  public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
    LOG.debug("Error ", cause);
    resp = ExceptionHandler.exceptionCaught(cause);
    resp.headers().set(CONNECTION, CLOSE);
    ctx.writeAndFlush(resp).addListener(ChannelFutureListener.CLOSE);
  }

  private void onCreate(ChannelHandlerContext ctx)
    throws IOException, URISyntaxException {
    writeContinueHeader(ctx);

    final String nnId = params.namenodeId();
    final int bufferSize = params.bufferSize();
    final short replication = params.replication();

View on GitHub (pinned to 2add963021)

Solutions

1. Use a valid WebHDFS operation name (e.g. OPEN, CREATE, MKDIRS, LISTSTATUS) in the request URL.
2. Check the client code or curl command for a misspelled or unsupported op parameter.

When it happens

Trigger: WebHDFS request on the DataNode with an HTTP/operation parameter that does not map to a supported WebHDFS op.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/95f7f8d4116bb1e9. Report an issue: GitHub.