Rust Rate Limiter

A gRPC-based rate limiter service built with Rust, Tonic, and Tokio.

Building

cargo build

Running

cargo run

The server will start listening on 127.0.0.1:50051 (IPv4 localhost on port 50051).

Testing with grpcurl

# Install grpcurl if not already installed
# https://github.com/fullstorydev/grpcurl/releases

# Send a ping request (reflection enabled, no .proto needed)
grpcurl -plaintext -d '{"message":"hello"}' 127.0.0.1:50051 rate_limiter.RateLimiter/Ping

Example Clients and Load Tests

The examples/ directory contains several binaries for testing and benchmarking:

• client.rs: Simple gRPC client for manual requests.
• load_test.rs: Multi-threaded, configurable load test for rate limiter and heartbeat endpoints.
• loop_load_test.rs: Repeated requests in a loop (single-threaded).
• single_threaded_load_test.rs: Basic single-threaded load test for baseline throughput.

Running the Server

cargo run

Running the Example Client

cargo run --example client

Running the Main Load Test

Always run load tests with the --release flag to avoid debug-mode overhead.

# Run rate limiter endpoint load test
cargo run --release --example load_test -- rate

# Run heartbeat endpoint load test
cargo run --release --example load_test -- heartbeat

# Run both endpoints
cargo run --release --example load_test -- both

Running Other Load Test Variants

cargo run --release --example loop_load_test
cargo run --release --example single_threaded_load_test

Load Test Results

Metric	Value
Throughput (req/s)	300,000
Mode	release
Test	both endpoints

Project Structure

• proto/ - Protocol Buffer definitions
• src/ - Rust source code
• build.rs - Build script to compile proto files
• examples/ - Example client binaries (run via cargo run --example client)