I read from some books that Phusion Passenger is the answer to easy Ruby on Rails deployment. But my friend said that first there was Apache + bunch of Mongrels, and then lighttpd, and then nginx, and now Passenger, and it seems endless...
he also said he uses dreamhost which uses Passenger, and sometimes he sees his request not being processed.
So I wonder if Passenger is the final answer to RoR deployment? do you use it and used the "ab" command to test if the site is doing quite well?
short answer: yes.
long answer: yeeeeeeeeeeeeeeesssssssssssssssss.
In all seriousness, Phusion Passenger and Ruby Enterprise Edition have taken out pretty much all of the pain of moving a Rails app into production. Previous approaches, including running a suite of Mongrels, required lots of setup surrounding starting, stopping, and recycling listener processes that Passenger handles transparently, or via simple Apache (or nginx) configuration options. And REE's complementary garbage collector means that forking off a new listener uses MUCH less memory, and is faster to boot (in Passenger's "smart" spawning mode).
Edit: @srboisvert makes a very good point; Passenger isn't the final answer to RoR deployment, but for now it's my favorite by far. One day, after a lot of hard engineering problems are solved, mainstream Ruby will probably move from hosting RoR using a multi-process model to a single-process model, which would make management even easier than with Passenger.