otp on Poeticoding

Realtime Market-Data Updates with WebSocket and Elixir

Wed, 19 Dec 2018 14:00:00 +0000

Cryptocurrency exchanges usually open their realtime feed for free and, like Coinbase Pro, without even having to create an account. This gives us a great way to build an architecture around realtime market data. In this article we see how to build an Elixir application to get realtime updates from the coinbase websocket feed, handling crashes and disconnections.

Running Elixir in Docker Containers

Wed, 12 Dec 2018 14:15:00 +0000

One of the wonderful things about Docker Containers is that you can easily freeze your environment and application in a Docker Image, and deploy it in production without worrying about installing dependencies on your servers. It just works. This is also great for debugging. If something doesn’t work in production, you can run exactly the same image locally in matter of seconds. The features and advantages of docker obviously don’t stop here. In this article we see how to use Docker to run our development Elixir environment and to run multiple Elixir Nodes over a Docker bridge network.

Build a Simple Persistent Key-Value Store in Elixir, using Logs - Part 2

Tue, 04 Dec 2018 16:40:00 +0000

Published articles in the series:

Part 1
Part 2 (this article)

In the part 1, we’ve introduced a simple implementation of a kv-store engine, written in Elixir. We developed three modules: an Index, a Writer and a Reader. The Writer writers the values in a log-file keeping the keys in a in-memory Index. Since the state of the index is only kept in memory, once the index process fails, or the whole engine crashes, we are not able to distinguish the values …