While working on setup automation I often ran into HTTP startup challenges.
It can take up to 40-50 seconds until the HTTP task is started.
If you look at open files, you notice that each thread has more than 70 files open.
This sums up to up quite some files and the HTTP server start/stop time is much slower.
In case you don't use XPages there is a simple switch to disable the XPages run-time and only load the standard Java components.
notes.ini INotesDisableXPageCMD=1
I first had the impression Java in general would cause overhead on start. But my tests drilled down to XPages/OSGI.
This is a companion discussion topic for the original entry at https://blog.nashcom.de/nashcomblog.nsf/dx/disabling-xpages-if-not-needed-reduces-open-files-and-http-startstop-time.htm