If you have a long running job that leaks few bytes of memory it will eventually will consume all of your memory with time.
Of course you need to find out where is the memory leak and fix it, but sometimes you can’t because it on a code that you use and not your own code.
Apache webserver solve this problem by using
MaxRequestsPerChild directive, which tells Apache worker process to die after serving a specified number of requests (e.g. 1000), which will free all the memory the process acquired during operation.
I had a similar problem with Django under Gunicorn, my Gunicorn workers memory keep growing and growing, to solve it I used Gunicorn option
-max-requests, which works the same as Apache’s
gunicorn apps.wsgi:application -b 127.0.0.1:8080 --workers 8 --max-requests 1000