Relationship of "ulimit -a" to fs.file-max

Question

I am on an amazon linux ec2 instance and need to increase the files limit (to run spark).

It had been my recollection there were a way to do something like

ulimit -n 8192

But that is not "taking" ulimit -a still shows:

open files                      (-n) 1024

From sudo su - root the following was attempted:

sysctl  -w fs.file-max=16335
fs.file-max = 16335   

So it seemed to work .. except ..:

open files                      (-n) 1024

Why are these commands not "sticking" ?

Answer 1

Finally found a suitable reference

https://glassonionblog.wordpress.com/2013/01/27/increase-ulimit-and-file-descriptors-limit/