Let’s first talk about the reason I started looking for this. I have a couple of services running in Ubuntu including DBs like MySQL, MongoDB, etc. along with running nGinx and other services.

However, sometimes, I noticed that the memory consumption goes upwards and it’s wise to know which process could be responsible for this.

I decided to look into this using the ps command

ps -eo pmem,pcpu,pid,args | tail -n +2 | sort -rnk 1 | head

Let’s look at the arguments provided:

ps	Current process snapshot report
-e	Select all processes. Identical to -A.
-o	format is a single argument in the form of a blank-separated or comma-separated list, which offers a way to specify individual output columns.
pmem	the ratio of the process’s resident set size to the physical memory on the machine, expressed as a percentage.
pcpu	CPU utilization of the process in the “##.#” format. Currently, it is the CPU time used divided by the time the process has been running (cputime/real time ratio), expressed as a percentage.
pid	A number representing the process ID
args	Command with all its arguments as a string.
tail -n +2	Output lines starting to the second line
sort -rnk 1	r (reverse) n(numeric sort) by column 1 i.e., pmem
head	Output the first 10 lines

Hope it helps!