Roughly 8 months back, I wrote an article comparing the performance of Python against Golang, and the latter emerged a clear winner. I went on to explore Golang at depth and even delivered a few talks in which I leveraged the power of goroutines and channels to build demos which showcased parallel processing and lightweight AI agent containerization.

However, my quest for extreme optimisation kept luring me towards Rust every few weeks, until today, when I decided to make the languages go head-to-head in the one domain I work on often - building APIs. The code used for testing is available here - https://github.com/xprilion/go-vs-rust-api-performance-test. I just ran the tests on my laptop without any changes in RAM/running apps while testing it.

Setting Up the Servers

To ensure an apples-to-apples comparison, I wrote minimal web servers in both Golang and Rust, which would be subjected to the same load tests. Since both languages offer compiling the code to performant binaries, I did that.

Then I ran the binaries on port 8080 for Golang and 8081 for Rust and stress tested them using the hey tool.

Golang Server

// server.go
package main

import (
    "fmt"
    "net/http"
)

func greetHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, visitor! You've requested: %s\n", r.URL.Path)
}

func main() {
    http.HandleFunc("/", greetHandler)
    fmt.Println("Starting server on :8080")
    if err := http.ListenAndServe(":8080", nil); err != nil {
        fmt.Printf("Error starting server: %s\n", err)
    }
}

Compiled and started with:

go build -o mygoserver server.go
./mygoserver

Rust Server

use warp::Filter;

#[tokio::main]
async fn main() {
    let route = warp::path::param()
        .map(|path: String| format!("Hello, visitor! You've requested: /{}", path));
    warp::serve(route).run(([127, 0, 0, 1], 8081)).await;
}

Ran it using:

cargo run --release

Load Testing Tools

I chose to use the hey tool for load testing. It's lightweight, written in Golang, and provides insightful metrics such as requests per second, latency distributions, and error rates.

go install github.com/rakyll/hey@latest

Running the Performance Tests

I conducted a series of load tests on both servers. Here's the breakdown:

Time taken to respond to 10,000 requests with 100 concurrent requests
How many requests the servers could handle in 5 seconds with 100 concurrent requests
How many requests the servers could handle in 5 seconds with 1 concurrent request

Test Results

The following table summarizes the results of the performance tests.

Language	Requests	Concurrency	Time Taken	Requests/sec
Golang	10,000	100	0.176 s	95,776.8
Rust	10,000	100	0.124 s	142,696.9
Golang	478,958	100	5 s	95,776.8
Rust	713,630	100	5 s	142,696.9
Golang	121,973	1	5 s	24,392.8
Rust	152,649	1	5 s	30,527.5

Breakdown of Results

Test 1: 10,000 Requests, 100 Concurrent Connections

In this test, Rust outperformed Golang significantly, handling 10,000 requests with 100 concurrent connections in 0.124 seconds, compared to Golang's 0.176 seconds. Rust also achieved a higher requests-per-second rate (142,696.9 vs. 95,776.8).

Test 2: 5 Seconds, 100 Concurrent Connections

Over 5 seconds, Rust processed 713,630 requests, while Golang managed 478,958. Once again, Rust demonstrated superior handling of high-concurrency scenarios.

Test 3: 5 Seconds, 1 Concurrent Connection

Even with only one concurrent connection, Rust managed to outperform Golang, handling 30,527.5 requests per second compared to Golang's 24,392.8.

Hence the verdict came out to be:

Single concurrent request: Rust is 1.25x faster than Golang.
100 concurrent requests: Rust is 1.49x faster than Golang.

Conclusion

The results speak for themselves: Rust outperforms Golang across all tests, particularly under high concurrency. While Golang is still significantly faster than Python (based on earlier tests), Rust offers even better performance with lower latency and higher throughput.

In a world where efficiency matters, it's clear that Rust is an exceptional choice for performance-critical applications. However, Golang's simplicity, ease of use, and its own solid performance still make it a great choice for a wide range of projects.

Friends, Romans, countrymen, I am so learning Rust AND Golang.

Golang vs Rust: API Performance Load Test