If you have a Rails app that sends e-mails, you are probably using ActionMailer. Unfortunately, starting with Rails 2.2.2, you may have encountered a wonderfully annoying little error that looks like this:
OpenSSL::SSL::SSLError (hostname was not match with the server certificate):
/usr/lib/ruby/1.8/openssl/ssl.rb:123:in `post_connection_check'
/usr/lib/ruby/1.8/net/smtp.rb:582:in `tlsconnect'
/usr/lib/ruby/1.8/net/smtp.rb:562:in `do_start'
/usr/lib/ruby/1.8/net/smtp.rb:525:in `start'
[...]
The are quite a few sites out there that give monkey patches for this problem, but those aren’t very useful because the next time you upgrade Rails, the monkey patch gets obliterated and you’re back to square 1. And then you have to remember how you monkeyed with it the last time to get it working again. Ug…
Instead, fix it the right way!
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Scottie Programming rails, ruby
If you use Rails on a high-traffic site, you know that as your number of users increases, you have three main options:
- Add servers to handle the load
- Optimize your queries
- Improve your caching scheme
You may be surprised to know that most people go for Door #1. It’s a lot easier. You don’t have to really do tons of work to rewrite your code and actually make it efficient. You don’t have to ditch “the Rails Way” and start actually thinking about what the database layer is doing to slow your site down to a crawl. And you don’t have to think about how Rails’ cache expiry functions actually work. Finally – and best of all – you can just pass the costs on to your customer, right??
I recently read an article that really slayed me. It was about a “niche site” that runs on Rails. They get 50 million hits a month, and they have SIX servers to handle the load, including multiple dedicated DB servers. I designed a Rails site that now gets 27 million hits a month, and it runs Rails on a single 1.86 GHz dual-core server with 3GB of RAM. By my calculations, the site could easily handle twice as many hits as it does now. Most of the time, the load is very low and the CPU and disk accesses hover at a few percent.
Of course, to achieve good performance, you can use things like Phusion Passenger. But that alone ain’t gonna cut it. You also have to optimize your queries, stop doing things The Rails Way and start thinking for yourself, and of course optimize your caching scheme.
In this episode, I’m going to tell you one very cool way to turbocharge your caching setup!
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Scottie Programming cache, rails, ruby
Say you were using the active_record_store for sessions in Rails 2.2, and you added your own custom column(s) to the default sessions table in your database. You might have done so because you wanted to add, say, the user’s id number to each entry in the sessions table. This would let you do things like quickly and efficiently delete a user’s session.
Unfortunately, when you upgrade to Rails 2.3.2, your session hack will be seriously busted. Cookies will work great, and so will the standard session scheme, but your custom column in the sessions table won’t be updated. Worse yet, you’ll get a lovely error when you do things the old way. The problem is due to 2.3.2′s new “lazy sessions“. In short, unless a session is accessed, it doesn’t load all the session handling stuff. If you don’t want to use sessions, you don’t have to turn them off anymore.
So, that’s great, but your custom sessions table is still broken. There are no solutions posted anywhere that I could find, so I took the liberty of figuring it out myself. Here’s what to do…
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Scottie Programming rails, ruby
Ruby on Rails has become a rather popular framework that many have used to easily and quickly create some pretty powerful web sites. As with any web programming language or framework, it certainly does have its problems. For example, Rails has never been well-known for its incredibly speedy database layer. In fact, if you’re not careful, you can make a glorious application that will run your server into the ground because of all the heavy behind-the-scenes DB queries.
Another problem is that a lot of people get their Rails coding tips and tricks from others – basically what you’re doing right now! The solutions you find online aren’t always optimal, and are sometimes downright scary.
Take a custom 404 error page. It’s easy enough to make, but you have to be careful about how you actually implement it.
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Scottie Programming rails, ruby
