It's still there; I just moved it to an appendix and added a link. Keepalive is documented in the
Install OpenACS 4.6.2 chapter:
Assuming AOLserver started cleanly in the previous step, we'll
set it up so that it's always running, and automatically restarts
whenever it dies or is stopped. This step is strongly recommended,
even for development sites, because it makes install and maintenance
much simpler.
The Reference Platform uses Daemontools to control AOLserver.
A simpler method, using init, is here
My reasoning was that 1) we should only document one approach in the main flow of the documentation, 2) the community seems pretty evenly split on which to use, 3) daemontools is more functional (appropriate for other programs, finer control). If it's too hard to find, please tell me how better to link it or place it. If there is demand to swap them so that inittab is in the main flow and daemontools is the alternate method, I can do that too.