Implementation:Ray project Ray Serve RequestContext

Knowledge Sources	Ray Ray Serve
Domains	Model_Serving, Distributed_Computing
Last Updated	2026-02-13 16:00 GMT

Overview

RequestContext provides thread-local storage for per-request metadata accessible within Ray Serve deployment code during request processing.

Description

RequestContext uses a ThreadLocal variable to store request-scoped context information including route, request ID, application name, and multiplexed model ID. A default empty context is used as the initial value for each thread. Static methods set(), get(), and clean() manage the context lifecycle, ensuring each concurrent request thread has isolated context data without requiring explicit parameter passing.

Usage

Use RequestContext within deployment handler code to access metadata about the current request, such as the route path, request ID for tracing, application name, or multiplexed model ID. The context is automatically set by the Serve framework before invoking the handler and should be cleaned up after processing completes.

Code Reference

Source Location

• Repository: Ray
• File: java/serve/src/main/java/io/ray/serve/context/RequestContext.java

Signature

public class RequestContext {

    public static void set(
        String route, String requestId, String appName, String multiplexedModelId)

    public static RequestContext get()

    public static void clean()
}

Import

import io.ray.serve.context.RequestContext;

I/O Contract

Fields

Field	Type	Description
route	String	The HTTP route path for the current request
requestId	String	Unique identifier for the current request
appName	String	Name of the Ray Serve application handling the request
multiplexedModelId	String	Model ID when using multiplexed model serving

Static Methods

Method	Return Type	Description
set(route, requestId, appName, multiplexedModelId)	void	Sets the thread-local request context; null values fall back to defaults
get()	RequestContext	Returns the current thread's request context
clean()	void	Removes the thread-local context, resetting to the default

Instance Methods

Method	Return Type	Description
getRoute()	String	Returns the route path
getRequestId()	String	Returns the request ID
getAppName()	String	Returns the application name
getMultiplexedModelId()	String	Returns the multiplexed model ID

Usage Examples

// Inside a deployment handler method
public Object handleRequest(Object request) {
    // Access the current request context
    RequestContext ctx = RequestContext.get();

    String route = ctx.getRoute();
    String requestId = ctx.getRequestId();
    String appName = ctx.getAppName();

    logger.info("Processing request {} on route {} for app {}",
        requestId, route, appName);

    try {
        // Process the request
        return doWork(request);
    } finally {
        // Context is typically cleaned up by the framework
        RequestContext.clean();
    }
}

Related Pages

• Environment:Ray_project_Ray_Java_Build_Environment