As you probably know the default setting for Domino is to have the just in time compiler turned off.

Enabled in notes.ini with:
JavaEnableJIT=1

When you read the docs to turn it on they mention that it might cause problems to turn it on.

I have been running it for a time at som unimportant servers that run a lt of java and have had no problems at all.

So I will go ahead and enable it on some more servers.

Anyone had any troubles with that setting?

I think Joachim Dagerot and Fredrik Stöckel had a PMR with IBM about some XSL transforming taking 4 minutes when it should take 4 seconds and that setting solved it. Has it had any side effects?

Yes, we had some (rather odd) issues with performance and XSL transformation and had to turn JIT on . As far as I can tell, we haven't had any problems related to it being turned on after that (as far as I can tell).

This was on a dedicated server (cluster) running web-applications only (no mail or other standard notes apps).

I think the transformation takes about 1-3 sec now (from up to 4 mins before) :)

Good. I enabled it on a development server today.

A large PDF generation that took 50 seconds before now completes around 12 seconds. That is pretty good considering there is a lot of network operations involved that cant be done any faster.

After seeing the difference the customer is willing to enable it on the production server. I am starting to feel pretty confident about this setting.

...just found out that the the JIT compiler is enabled by default in R8 :)