We built an event driven system in my team over 2 years ago that sometime back ran into database transaction deadlock problems which puzzled me enough to want to take a deeper look into what happened. This mini-post is a bit of documentation of that investigation.
Recently a planned AWS Aurora database failover/master reboot caused database connection failures in one of our services which caused me to delve deeper into how MySql driver manages connections under the hood.
Many articles talk about the what of this style but in my view, not enough talk about the how. In this post, I am going to try and show one way to actually structure the solution to be more in line with the hexagonal ports and adapters style.