Thoughts of Geoff

Some writing by Geoff Petrie

Fixing a Slow Localhost Webrick Server

For the longest time I could not get Webrick to work for me. It would boot up with rails s but would take several seconds for even the default landing page of a rails app to load. It was terrible.

I resorted to using Thin as my default browser by making sure it was in all my Gem files, but I still wanted to figure out why Webrick simply wouldn’t work for me. (Truth is, Thin is a better web server, but I still wanted to get Webrick to work for me.)

Searching for “webrick slow” brought up a possible solution via Stack Overflow. Basically you change the :DoNotReverseLookup symbol in your global Webrick config from nil to true.

If you’re on OS X Lion you’ll find the Webrick configuration here:


I found the :DoNotReverseLookup configuration on line 36.

Once I made the change Webrick was screaming fast. I’m pretty happy about it.

I still haven’t found the definitive reason why this problem is occurring, but at least this change appears to fix things for me.

Please note, depending on the version of Ruby you’re running ruby-1.9.3-p362 could be something different. Just as long as you’re changing the confg.rb file in the webrick/ directory, you should be fine.