EdgeGraphql

This Phoenix application uses Absinthe to handle the GraphQL implementation and Cachex to deal with caching. GraphQL query results are fetched from Punk api using HTTPoison. We can then deploy it to multiple regions with Fly to cache queries closer to the user.

You also have a companion article where we talk about the reasons you might want to do something like this and some interest bits of this sample application.

To run it locally:

• Clone the repo

• Install dependencies with mix deps.get

• Start Phoenix endpoint with mix phx.server

  Now you can visit localhost:4000/ from your browser and play with the available query. The following query is available to try it out:

  {
    beers(name:"beer name") {
      name,
      abv,
      firstBrewed,
      foodPairing
    }
  }
  

Deploy to Fly:

• Create your account on Fly
• Install flyctl
• Create a Fly app: flyctl apps create
• Change the host of your config/prod.exs to match your Fly app name.
• Deploy the app with flyctl deploy
• You can navigate to https://your-app.fly.dev/ and play around.

Testing latency:

You can use cURL to see how long your requests are taking.

Punk API:
beer by name
curl 'https://api.punkapi.com/v2/beers?beer_name=Punk' \
-o /dev/null -sS \
-w "Timings\n------\ntotal:   %{time_total}\nconnect: %{time_connect}\ntls:     %{time_appconnect}\n"


GraphQL API:
beer by name:
curl 'https://<appname>.fly.dev/?variables=%7B%7D&query=%7B%0A%20%20beers(name%3A%22punk%22)%20%7B%0A%20%20%20%20name%2C%0A%20%20%20%20abv%2C%0A%20%20%20%20firstBrewed%2C%0A%20%20%20%20foodPairing%0A%20%20%7D%0A%7D' \
-o /dev/null -sS \
-X GET \
-H "Content-Type: application/json" \
-w "Timings\n------\ntotal:   %{time_total}\nconnect: %{time_connect}\ntls:     %{time_appconnect}\n"

You could also flyctl logs and check the response time from there.

Some numbers:

Hit on Source Api	seconds
total:	0,296964
connect:	0,123632
tls:	0,218332

Hit on App - Uncached	seconds
total:	0,628647
connect:	0,066114
tls:	0,324010

Hit on App - Cached	seconds
total:	0,178687
connect:	0,046614
tls:	0,109855