Go http server slow benchmark performance

Question

I was trying to find the maximum throughput of a go webserver. I ran simplewebserver on a 8 core machine(Intel Xeon 2.5 Mhz) and ran wrk tool on a different 8 core machine. Iperf command shows around 8-10Gbps between these machines . Initially, I made a mistake by using apache ab tool that gave only 16k requests/second. The problem was same as link. Now when I switched to wrk tool, I am getting around 90k requests per second and ~ 11MB/sec.

on the first 8 core machine, I ran simplewebserver.go

package main

import (
   "io"
    "net/http"
    "runtime"
)

func hello(w http.ResponseWriter, r *http.Request) {
    io.WriteString(w, "Hello world!")
}

 func main() {
    runtime.GOMAXPROCS(8)
    http.HandleFunc("/", hello)
    http.ListenAndServe(":8000", nil)
 }

On a different 8 core machine, i ran

 ./wrk -t8 -c1000 -d10s http://10.0.0.6:8000/

Result:

Running 10s test @ http://10.0.0.6:8000/
8 threads and 1000 connections
Thread Stats   Avg      Stdev     Max   +/- Stdev
Latency    42.65ms  114.89ms   1.96s    91.33%
Req/Sec    11.54k     3.01k   25.10k    74.88%
923158 requests in 10.10s, 113.57MB read
Socket errors: connect 0, read 0, write 0, timeout 20
Requests/sec:  91415.11
Transfer/sec:     11.25MB

Can i say that I have reached maximum throughput of a golang web server? I am getting 11 MB/sec which looks quite small for the basic program. If I run the wrk tool on www.google.com page, I am getting around 200 MB/sec. Even for larger complex computing systems like kafka(java server), the benchmark results get more than 70 MB/sec(https://engineering.linkedin.com/kafka/benchmarking-apache-kafka-2-million-writes-second-three-cheap-machines). How can a golang server handle extreme workloads of millions of requests per second(more than 100MB/sec minimum)? Am I wrong in any assumptions?

UPDATE:

I ran the same program on a 16 core machine with the same specs. I changed the maxprocs to 16 and results went higher to 120k requests/sec. I feel that I have the reached the maximum of golang http server and hence I am not finding any significant increment in the requests/sec.

Answer 1

Golang net/http is rather slow. If the goal is to maximize the requests rate there are other implementations. For example https://github.com/valyala/fasthttp In my tests fasthttp doubles the query rate. My test is a short request and short reply.

The library comes with limitations, like no HTTP/2 support. If you need HTTP for REST API and you are not looking for interoperability fasthttp will fit nicely

Answer 2

"premature optimization is the root of all evil"1

I would suggest building something for your use case and then attempting to optimize. It is difficult to build a good benchmark that tests what you want so make sure you are testing what you want and not something like the speed of your router.