two weeks back the application starting loading extremely slow. Frequently getting error pages, tried to use snapshopt, debug, logs, nothing can be obtained.
Lucee is on ubuntu and SQL server is on a separted machine connected through IP for data requests.
did all lucee templates settings increase jvm memory size but nothing seem to be working.
Could you please tell us and specify what type of errors you are getting? Do you have any stack traces with more information? This could be SQL or DB issue, networking, an connector issue or whatever. But without any information and details it will be very hard for us to help.
I would recommend installing a tool like FusionRector, which will give you great insights into what your application is doing. Right now, your question is basically unanswerable as the issue could literally be anything in the world.
If you want more help troubleshooting, you can purchase consulting services. My company, Ortus Solutions, offers this along with other great CF people like Charlie Arehart and CF Web Tools. I will tell you, Ortus and Charlie at least will require you purchase FusionReactor either way, so you may as well start down that path and see what you can find on your own.