Benchmarking Go in the cloud

Go now seems to be a natural choice for writing your next microservice or web app. It’s mature and fast.

But where would you host your app? In this post I will compare some popular PaaS (platform-as-a-service) and how the same primitive Go web app performs on each of them.

Go

I’m using the latest Go compiler and the latest version of Gin framework with zero-allocation router.

Gin is configured to run in release mode, but I used default gin settings, where a single-line log per request is printed, because that’s what most web apps would like to have anyway.

App has one route “/ping” and responds with a static string “pong” (as in Gin’s example).

Benchmarks are made using wrk utility. I used 2 threads (my laptop is not that powerful to run more) and 100 connections.

main.go:

package main

import (
        "os"

        "github.com/gin-gonic/gin"
)

func main() {
        addr := ":8080"
        if env := os.Getenv("PORT"); env != "" {
                addr = ":" + env
        }
        if env := os.Getenv("OPENSHIFT_GO_PORT"); env != "" {
                addr = os.Getenv("OPENSHIFT_GO_IP") + ":" + env
        }
        gin.SetMode(gin.ReleaseMode)
        r := gin.Default()
        r.GET("/ping", func(c *gin.Context) {
                c.String(200, "pong")
        })
        r.Run(addr)
}

Procfile:

web: go-cloud-benchmark

Godeps generated automatically with godep save.

My laptop

Old dual-core Thinkpad X120e running Ubuntu 14.04 LTS. Since I’ve been running other apps during this test - the result is just a rough approximation of how my dev machine performs.

In the logs Gin reports that each request takes it 7..30 microseconds to process. Here’s what wrk says:

Running 30s test @ http://localhost:8080/ping
	2 threads and 100 connections
	Thread Stats   Avg      Stdev     Max   +/- Stdev
		Latency    68.48ms  104.17ms   1.56s    93.11%
		Req/Sec     1.05k   406.19     3.47k    75.26%
	62189 requests in 30.08s, 7.12MB read
Requests/sec:   2067.63
Transfer/sec:    242.30KB

Heroku

Heroku is a well-known cloud platform, only one app can be hosted for free. Integration with Github is super-easy and deployment procedure is just a single button click (which can be automated as well).

Running 30s test @ http://bench.herokuapp.com/ping
	2 threads and 100 connections
	Thread Stats   Avg      Stdev     Max   +/- Stdev
		Latency    90.30ms   41.55ms 643.77ms   88.68%
		Req/Sec   569.23    186.85     0.89k    76.95%
	33778 requests in 30.08s, 5.67MB read
Requests/sec:   1122.88
Transfer/sec:    192.95KB

OpenShift

OpenShift is a cloud platform made by RedHat. It allows you to run up to 3 apps for free. As with Heroku, you can just enter a link to your github sources and the git branch name, and the deployment will happen automatically.

There is a ready-to-use Go cartridge (aka gear aka dyno), but beware that your app port is not in the $PORT env variable, but in $OPENSHIFT_GO_PORT. Also, you should care about $OPENSHIFT_GO_IP variable, it tells where to bind you listening socket to.

At the moment OpenShift Go cartridge still uses Go 1.4, so this might affect the performance due to GC improvements they made in Go 1.5.

Running 30s test @ http://bench-tunes.rhcloud.com/ping
  2 threads and 100 connections
 Thread Stats   Avg      Stdev     Max   +/- Stdev
   Latency   171.70ms   87.78ms   1.96s    92.20%
   Req/Sec   305.20    114.46   505.00     65.20%
  17990 requests in 30.08s, 2.46MB read
Requests/sec:    597.99
Transfer/sec:     83.57KB

Yes, I ran the test several times, and the numbers were never higher than 650 requests per second (which happened once).

Cool feature of OpenShift is automatic scaling. I only had 2 gears available for scaling, and here’s the results with the load balancer they provide:

Running 30s test @ http://bench-tunes.rhcloud.com/ping
  2 threads and 100 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   364.71ms  240.09ms   1.91s    93.57%
    Req/Sec    80.35     49.57   262.00     62.11%
  4547 requests in 30.07s, 1.25MB read
  Socket errors: connect 0, read 0, write 0, timeout 23
  Non-2xx or 3xx responses: 4547
Requests/sec:    151.22
Transfer/sec:     42.63KB

Wait… I wish someone could explain this to me - how scaling onto another gear makes the app 3 times slower? Tried the test multiple times, results are pretty much the same.

DigitalOcean + Dokku

Digital Ocean is a well-known hosting provider. Although you can not get a free VM, you can buy the cheapest one for 5$ per month and install Dokku there.

Dokku is a DIY Heroku alternative. It uses Docker and Heroku buildpacks to create app containers.

So I only added a remote git branch pointing to my existing 5$ DigitalOcean VM and made a git push. A few seconds later my app was up and running.

Running 30s test @ http://dokku.trikita.co:32777/ping
  2 threads and 100 connections
	Thread Stats   Avg      Stdev     Max   +/- Stdev
		Latency   137.23ms   24.27ms 817.04ms   97.53%
		Req/Sec   367.39     54.15   480.00     71.14%
	21855 requests in 30.05s, 2.50MB read
Requests/sec:    727.20
Transfer/sec:     85.22KB

AWS EC2 + Dokku

Amazon provides its own Elastic BeanStalk with Docker, but my general impression was rather negative because the deployment procedure was way too slow.

Still, you can always install Dokku onto your regular AWS EC2 instance. I used the existing t2.micro instance.

Running 30s test @ http://52.25.xx.xx:32769/ping
  2 threads and 100 connections
	Thread Stats   Avg      Stdev     Max   +/- Stdev
		Latency   216.62ms   28.15ms   1.08s    97.41%
		Req/Sec   232.62     55.81   480.00     75.04%
	13724 requests in 30.08s, 1.57MB read
Requests/sec:    456.20
Transfer/sec:     53.46KB

Yep, even slower than OpenShift. Tried multiple times.

Scaleway

UPD Sep 18th I’ve just discovered Scaleway, someone mentioned that Camlistore can be installed there for only 3 EUR/month. They offer a 4-core ARM server with 2GB of RAM, and it can perfectly run Go (of course, the binraries compiled for ARM). Test app used all 4 cores (otherwise the speed was about 2-3 times slower).

Running 10s test @ http://xxx.xx.xx.85:8080/ping
  2 threads and 100 connections
	Thread Stats   Avg      Stdev     Max   +/- Stdev
		Latency   212.17ms  146.26ms   1.86s    91.67%
		Req/Sec   255.42    109.43   595.00     73.20%
	4977 requests in 10.01s, 583.24KB read
Requests/sec:    497.07
Transfer/sec:     58.25KB

Summary

Just summing up:

localhost:           2067 / free :)
Heroku:              1122 / 1 free dyno, or 7$/month (0.009$/hour)
DigitalOcean/Dokku:   727 / 5$/month (0.007$/hour), multiple containers
OpenShift:            597 / 3 free cartridges, or 0.02$/hour
Scaleway:             497 / 3.41$/month (0.005$/hour), multiple containers
AWS T2.micro/Dokku:   456 / 0.013$/hour, multiple containers

The only dual-core machine here is my laptop, thus it wins the race. Other VMs seem to be single-core.

Altough my persontal preference is Digital Ocean, I like how well Heroku performs. If only they made free dyno available for 24 hours - it would be a great choice for development purposes.

I’m very surprised with the OpenShift balancer, I really was hoping it gives some dramatic improvements to performance. Also the pricing…

Finally, I didn’t expect Amazon to take the last place in this rating. It might be good for big apps, but for small experiments, well, they charge more than DigitalOcean does, yet they give about 40% worse performance.

I’ve tested Scaleway as soon as I have heard about it - low prices, more RAM, nice ARM architecture. Still, it seems to be slower than other platforms, but if you need larger storage or can optimize your app by running cache in RAM - it may be worth trying. It’s close to the cheapest AWS instances, but is 3 times cheaper and has more RAM.

P.S. I understand that this benchmark can show different numbers in your case. But if you have any comments or different results - let me know!

Posted on 2015-09-04

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