example-webserver

The plan was for this example webserver to use the fasthttp golang library due to its lower memory footprint over the native net/http golang library, as well as other significant benchmarking results. However, the external APIs we're sending requests to are not able to handle an incredible amount of load such that the faster HTTP golang library shouldn't matter that much.

We will include our "benchmark" results by running tests using wrk

We will be sending requests to 2 external services:

After profiling both of the above URLs (results in benchmarks directory), it is apparent the first one (uinames) does not allow as much traffic as the second by a significant amount. In order to work around this, we will be caching 500 random names.

Benchmarks

Setup

I noticed during benchmarking that I was seeing socket errors relating to too many files being opened.

{
  "file": "v1.go:48",
  "func": "randomNameJoke",
  "level": "info",
  "msg": "request to joke either returned an error or status code != 200dial tcp4 104.24.114.160:80: socket: too many open files"
}

I have seen this before, so I checked the limit on my machine by running uname -n. 256 on MacOS (argh). Even on an Ubuntu 18 VM, the default is 1024. So I increased it:

$ echo "fs.file-max=400000" >> /etc/sysctl.conf
$ sysctl -p

# And for good measure
$ reboot

Results

I ran the server on a machine with the following specs:

 OS: Ubuntu 18.04 bionic
 Kernel: x86_64 Linux 4.15.0-51-generic
 Uptime: 9m
 Packages: 557
 Shell: su
 CPU: Intel Xeon E312xx (Sandy Bridge, IBRS update) @ 4x 2GHz
 GPU:
 RAM: 179MiB / 15032MiB

Running 2m test @ http://localhost:5000/v1/
  12 threads and 400 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   176.51ms   32.00ms   1.67s    95.90%
    Req/Sec   185.53     42.64   333.00     74.00%
  Latency Distribution
     50%  170.86ms
     75%  173.76ms
     90%  178.00ms
     99%  328.44ms
  264893 requests in 2.00m, 48.80MB read
  Socket errors: connect 0, read 85, write 0, timeout 0
Requests/sec:   2206.00
Transfer/sec:    416.12KB

Building

There are 2 options for building and running this example webserver

1 Local dev env is setup

# Clone repo
$ git clone git@github.com:CamelCaseNotation/example-webserver.git

# Download latest Go version
# https://github.com/travis-ci/gimme#installation--usage
$ brew install gimme
$ gimme stable

# Download all dependencies
$ go mod tidy

# Build the binary
# This creates the binary at $(pwd)/bin/server
$ go build -o bin/server

# Run the server
$ ./bin/server

2 Docker is installed

# You can also just build the docker image and run the container

$ docker build .

# Previous command will end with "Successfully built __ID__"
# To start a container using that image as a daemon and exposing the default port of 5000 such that you can send requests to it via localhost:5000, run command below

$ docker run -d --name example-webserver -p 5000:5000 aff5bc597b5c

# See the container running
$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS                    NAMES
30709672cdd1        aff5bc597b5c        "/server"           About a minute ago   Up About a minute   0.0.0.0:5000->5000/tcp   example-webserver

# Stop and remove container when done
$ docker stop 30709672cdd1 && docker rm 30709672cdd1