Yesterday I had a strange problem with Docker during a build process. I use Linux Mint. I didn’t have enough space at the main system directory /. By default, Docker saves all data (images, volumes, etc.) in /var/lib/docker. Firstly I wanted to move this directory to the /home, but unfortunately, there was probably a problem with encryption, and Docker’s daemon couldn’t start properly. The second option was to move the directory to a hdd drive. But it also wasn’t a piece of cake (just Linux user normal day 😀 ).
In most systems, we use remote calls. Many factors may have an impact on these remote calls e.g. network latency, server availability and so on. So we should assume that something can go wrong. These calls can be potential bottlenecks, we don’t want user waiting for the response from the server very long, because external API is very slow or not available. Also if we have a few services which communicate with each other we shouldn’t aggravate the situation when one of them has too much traffic and slow down significantly. So how to do it correctly?
Writing tests should assure us that the code created by us is working correctly. Often we point out the code coverage factor and if we have 100% we can say that implemented solutions are correct. Are you sure? Maybe there is a tool that can give us more accurate feedback?
In the most of systems need to save data somewhere and in some way. ORM (Object-Relational Mapping), is the way of mapping the system to the database. ORM is the layer between database and application which deals with creating, updating, reading and deleting.