I’ve started playing with MongoMapper, and it’s quite excellent, but it does suffer very much from being young. There are lots of pieces missing that veterans of ActiveRecord will take for granted. I’ve been working around or patching them, for the most part, but I felt that my solution to `:counter_cache` deserved a post. In [...]
Author Archives: Chris Heald
Feb
10
2010
Safe action caching with Memcached
I’ve started using action caching more aggressively, to handle a large volume of not-signed-in search traffic. It composes a significant chunk of my site’s total traffic, but there’s no good reason to be recomputing full pages for all those long-tail hits. So, the obvious thing is to just implement a quick action cache. # Controller [...]
Dec
23
2009
Eight tips for getting the most out of your Rails app
Rails does an awful lot to optimize page generation, but there are a number of hacks, tweaks, and usage patterns you should be using to get the most out of your app. Configuration tweaks There’s a lot of the Rails stack that’s written in Ruby, which is great – it’s portable, it’s flexible, it works [...]
Dec
15
2009
When you have to store user passwords…
Today we got word of yet-another-database-hack-with-plaintext-passwords. This time, it’s RockYou, purveyor of many of those Facebook and Myspace apps you use. Oops. Every time this comes up, everyone says “How naive! They should have been using salted hashed passwords!” This is true in any case where you don’t need to use the password again on [...]
Dec
06
2009
Multibyte string slicing for fun and profit
Ran into a small issue in one of my user models. I was using a helper to display a user’s first name, last initial. It looked something like this: def display_name(user) "user.first_name #{user.last_name.slice(0,1)}" end Seems innocent enough, sure. Except…it doesn’t work in multibyte character sets. The first Cyrillic speaker to sign up blew that all [...]
Dec
05
2009
System date considered important
I’ve been slamming my head against the wall for the past two hours. I had an OAuth connection to a remote service working just dandy in development, but as soon as I tried to use that exact same code with the exact same config and exact same gems in production…I was getting “401 unauthorized” errors [...]
Jul
29
2009
Sweet-ass performance hacks: better_assets
HTTP overhead is expensive. DNS lookups are expensive. Start dropping a bunch of Twitter widgets, Google ads, and GetSatisfaction buttons into your killer new Web 2.0 social networking site and you’ll find that your painstakingly-optimized site has slowed to a crawl while the server sits there waiting on Amazon S3 to get its act together [...]
Jun
13
2009
Fine tuning your garbage collector
If you’re familiar with Ruby at all, you know that it can be a little wacky when it comes to memory usage. Most of us have observed a Mongrel/Passenger instance that starts out small and then grows by leaps and bounds, eventually settling on some uncomfortably high number. We’re going to fix that with Ruby [...]
Mar
28
2009
Quick tip: Strip URLs before parsing!
Rather than roll my own URL regexes, I prefer to let the existing libraries do the heavy lifting. Ruby has a uri library which is fantastic for parsing (and validating) URLs. For example, something like this might be used in a model validation: require ‘uri’ def validate_url(url) parsed_uri = URI::parse(url) rescue URI::InvalidURIError errors.add :url, "Sorry, [...]