Fib-Server

Assumptions and Caveats

• This server uses a global counter to track where the server is at in the fibonacci sequence - this has numeric limits. i.e. for fib(n) = x, n is between 0 and 18446744073709551615 and x is between 0 and 2^63 (machine dependent)
• Future versions could use a memcache/redis store to maintain sessions and users so that each user can track fib(n) separately

Benchmarks

Current benchmarks using wrk: Test: wrk -t12 -c500 -d20s http://<hosted-fib-server>/next

Running 20s test @ http://<hosted-fib-server>/next
  12 threads and 500 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   103.92ms  163.41ms   1.86s    96.19%
    Req/Sec   312.98    302.56     1.68k    80.59%
  56910 requests in 20.10s, 331.02MB read
  Socket errors: connect 251, read 0, write 0, timeout 0
Requests/sec:   2831.04
Transfer/sec:     16.47MB

Given that there are errors, there's certainly places to improve the server infrastructure and likely configuration

Fib-Server is a service API that exposes 3 primary endpoints:

/current Returns the current number in the servers fibonacci sequence

/previous Returns the previous number in the fibonacci sequence from current

/next Returns the next number in the fibonacci sequence from current and increments the central counter by 1 Note: If the server count reaches the uint64 max(18446744073709551615), it will reset back to 0

Deploying

Binary

This is designed to run on linux machine with 512mb RAM, 1 CPU, and port 80 open to HTTP traffic. The dist/ folder contains a binary ready to be deployed in that way.

Source Build

Clone the repo to your preferred destination

• Ensure you have go1.13 or higher installed
• Run go mod download to download the modules locally
• Run go build main.go or if you would prefer a custom named binary go build -o <appname>
• For statically linked binaries to ensure portability users can run env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o <appname> to produce a linux ready binary

Running the server

Once you have your binary, navigate to your host machine and within /etc/systemd/system/ run the command touch fib.service in order to create a systemd service entry to manage runtime of the server

A sufficient service file will look as such:

[Unit]
Description=Fibonacci Tracker API
After=network.target
StartLimitIntervalSec=0

[Service]
Type=simple
Restart=always
RestartSec=1
User=root
ExecStart=<binary-directory>/<appname> -addr=:80 -compress=true

[Install]
WantedBy=multi-user.target

To start the server from here, run systemctl start fib.service