Have you ever had any problem with memory? In the past week, I have had multiple memory problems, both in a containerized system, in single processes and in full virtual machines. I have learned that memory usage and statistics is not easy under Linux, and multiple problems can occur.
I found this article from Heroku that shows one of this problem with memory statistics inside containers. This is just the tip of the iceberg, but it is explaining well where is this problem and what are the solutions to it (currently only temporary solutions).