Document commonly seen Cumulocity connectivity issues with resolutions

[albinsuresh]

Is your documentation request related to a problem? Please describe.

Many customers face issues with cloud connectivity while connecting thin-edge to Cumulocity, mostly due to some misconfigurations either at the device side or in their cloud tenant. We've seen many such issues recurring again and again from one customer to another, where we've seen some recurring patterns in our debug approach as well as in our resolutions. Often times, the misconfigurations are beyond our control (like misconfigurations in their cloud tenant), where we can only detect/observe the issue from thin-edge and just suggest solutions rather than do something to fix it or even get around it.

So, it might make sense to document such recurring issues that customers are facing so that we can plan how we can improve our product, if possible, to avoid customers making such issues in future. Or at least guide them in the right direction with instructions on how to debug any external environmental issues and even suggest solutions.

Documenting such cases also help us developers share our debug approaches and tooling that we use to efficiently analyse an issue so that fellow developers dealing with such issues can also refer to this document and solve those issues quickly.

Describe the improvement you'd like

Create a live document with the most common issues around cloud connectivity that customers face and the resolutions that we come up with, including our approach in analysing/debugging such issues. This document can act like an FAQ doc that we or our future customers can refer to, to solve similar issues that they are facing.

While documenting the debug approach, describe the steps that we take to identify an issue with the mapper like checking the service status, journal logs, tracing the messages exchanged via the MQTT broker, directly connecting an MQTT client to Cumulocity etc.

[rina23q]

We are having two kinds of issues

1. Low debug-ability
2. Live document to collect the issues happened in the past

[rina23q]

Write a living document to collect troubles and solutions (FAQ guide).

The document should be publicly available and accessible.

Where? in our documentation. Will be located in the reference guide, and the page will be linked by mapper and agent. Also, the page will be linked directly by the repository main README.