title: Docker container memory usage not going down
body: <p>I have a flask web server running with docker-compose. <br>
  When the container first starts, it starts by using around <strong>200MB</strong> of memory but after some use goes up to <strong>1GB</strong> (docker stats). <br>
  However once it reaches high consumption, even when idle, the memory usage of the container is not decreasing and eventually hitting the limit - causing dead uwsgi workers and stopped processes.<br>
  Can someone explain what happens behind the curtain and how to have the container release unused memory?</p>