Feeling the slowdown blues after going 0.13?.
It’s
somewhat ironic that we heralded Rails 0.13 as being a great move
forward for the performance of Rails and then half the threads on the
mailing list is about “Rails is sLOOOW!”. We’ve found the problems,
though.
The first was with the MySQL/Ruby bindings, which
called GC.start whenever MySQL#free was called. And we just put in
MySQL#free in 0.13 to improve things after each select of rows. This
caused the garbage collector to run every time you selected something.
Doh!
The C-bindings didn’t have this problem, so it wasn’t
discovered by the core team right away, and that was posed as the
solution on the mailing list. Unfortunately, it’s not necessarily
trivial to compile native bindings on all platforms (notably Windows),
so having fast Ruby bindings was indeed important. They’re fast again,
but if you upgraded to the C-bindings you can be happy that you’re even
faster.
The second problem was that we plugged a big memory
leak in development mode, but doing so caused a total of 8 runs through
the so-called ObjectSpace after each action (basically iterating over
all objects in the interpreter 8 times, eeks!). On big applications
this could take a while. On Basecamp it took 2 seconds. After the fix
went in where we just traverse the ObjectSpace once, it’s down to a
comfortable 0.2 seconds (which is about 0.17 faster than it even was
before the memory leak fix!).
Thus, Rails 0.13.1 is near
forth coming. As in this weekend. If you cannot wait, and we certainly
won’t blame you, there are new beta gems that consist purely of bug
fixes. Upgrade with gem install rails --source http://gems.rubyonrails.org --include-dependencies.