Good morning all,
it was long time i was around with some solution to help me supporting something right now is really complex, but i need to do.
Nginx looks like me last solution, so i've started with preliminary test, now , and i'm asking you a little help to validate first if it is possible and how to accomplish. I would thanks in adavance whoever can be so kind to help me.

Scenario: a sinlge server (physical) with a lot of ram, near 96Gb that should be used to run from a minimun of 3 to 6 or even more tomcat istances with same configuration, apart listening port. The matter is that JVM running on big heap max memory took a life to complete Gargage collections, so it is a reasonable solution to split up the jvm with lower memory and run in parallel tomcat. But this should be done smoothly with one only real IP no subnet, no possibility to do L3 balance, so NGINX seems to be the only solution.

server NGINX+TOMCAT on the backend
NGINX on port 80
TOMCAT will run from 81 to 88 for example.

But, i have some constraints.

A) i have to use HTTP and HTTPS
B) sticky: who use tomcat1 should remain there for both HTTP/HTTPS protocol
C) if incoming IP is x.x.x.x it shoudl go to tomcat 8
D) if one of the tomcat is down, it won't be used anymore
E) if i have a peak of reqeustes, i should be able to add more instances without stopping anything and/or use backup servers realtime.

I believe NGINX can do it, but it is a matter of starting to read right documentantion.

Thank you for any help on this.

Michele