Master-Master Replication and Scaling of an Application between Each of the IoT Devices and the Cloud
In this article, I want to share with you how I solved a very interesting problem of synchronizing data between IoT devices and a cloud application.
I’ll start by outlining the general idea and the goals of my project. Then I’ll describe my implementation in greater detail. This is going to be a more technically advanced part, where I’ll be talking about the Contiki OS, databases, protocols and the like. In the end, I’ll summarize the technologies I used to implement the whole system.
So, let’s talk about the general idea first.
Here’s a scheme illustrating the final state of the whole system:
I have a user who can connect to IoT devices via a cloud service or directly (that is over Wi-Fi).
Also, I have an application server somewhere in the cloud and the cloud itself somewhere on the Internet. This cloud can be anything — for example, an AWS or Azure instance or it could be a dedicated server, it could be anything :)
The application server is connected to IoT devices over some protocol. I need this connection to exchange data between the application server and the IoT devices.
The IoT devices are connected to each other in some way (say, over Ethernet or Wi-Fi).
Also, I have more IoT devices generating some telemetry data, like light or temperature readings. There can be more than 100 and even over 1,000 devices.
Basically, my goal was to make it possible to exchange data between the cloud and these IoT devices.
Before I proceed, let me outline some requirements for my system: