Implementation:Apache Spark ProxyUtils

Knowledge Sources	Apache_Spark
Domains	Security, YARN, Web_UI
Last Updated	2026-02-08 22:00 GMT

Overview

Utility class providing HTTP proxy helper methods for redirect handling, error responses, and request validation in the YARN web proxy.

Description

ProxyUtils is a public utility class copied from Hadoop 3.4.0's `org.apache.hadoop.yarn.server.webproxy.ProxyUtils` and modified to use Jakarta Servlet APIs. It provides three static utility methods: `sendRedirect` for generating HTTP 302 redirects with an HTML body, `notFound` for generating HTTP 404 responses, and `rejectNonHttpRequests` for validating that incoming servlet requests are HTTP requests. The redirect method generates a user-friendly HTML page with a clickable link to the target URL using Hadoop's Hamlet HTML builder.

Usage

Use this class when implementing or extending YARN web proxy functionality in Spark. It is used internally by `AmIpFilter` to handle redirects and request validation. Application code generally does not call this directly.

Code Reference

Source Location

• Repository: Apache_Spark
• File: resource-managers/yarn/.../ProxyUtils.java
• Lines: 1-126

Signature

public class ProxyUtils {
    public static final String E_HTTP_HTTPS_ONLY =
        "This filter only works for HTTP/HTTPS";
    public static final String LOCATION = "Location";

    public static void sendRedirect(HttpServletRequest request,
        HttpServletResponse response, String target) throws IOException { ... }

    public static void notFound(HttpServletResponse resp, String message)
        throws IOException { ... }

    public static void rejectNonHttpRequests(ServletRequest req)
        throws ServletException { ... }
}

Import

import org.apache.spark.deploy.yarn.ProxyUtils;

I/O Contract

Inputs

Name	Type	Required	Description
request	HttpServletRequest	Yes (sendRedirect)	The original HTTP request
response	HttpServletResponse	Yes	The HTTP response to write to
target	String	Yes (sendRedirect)	Target URL for redirection
message	String	Yes (notFound)	Message to display on 404 page
req	ServletRequest	Yes (rejectNonHttp)	Request to validate

Outputs

Name	Type	Description
HTTP 302 response	HttpServletResponse	Redirect with Location header and HTML body
HTTP 404 response	HttpServletResponse	Not found with HTML message
ServletException	Exception	Thrown if request is not HTTP

Usage Examples

Redirect Usage

// Inside a servlet filter or handler:
ProxyUtils.rejectNonHttpRequests(req);
HttpServletRequest httpReq = (HttpServletRequest) req;
HttpServletResponse httpResp = (HttpServletResponse) resp;

// Redirect to the proxy URL
ProxyUtils.sendRedirect(httpReq, httpResp,
    "http://rm.example.com:8088/proxy/application_123");

Related Pages

• Principle:Apache_Spark_YARN_Web_Proxy_Security