Category: Ruby / Rails Page 2 of 7

What VPS / cloud instance provider gives you the best bang for buck for a small linux server? I’ve been focusing on evaluating providers at the low cost end, and reasonable latency to Australia – Linode Tokyo, Octopus Australia, RailsPlayground USA and Amazon Singapore. From the tech specs on a VPS, most providers look similar. However, when you have an instance, you often find huge variation in performance due to contention for CPU and disk on the node. For a simple test, I ran a small ruby script on each server every 20 minutes on cron, and logged the results to a CSV file over the same 5 days.

Here is the script:

start = Time.now

`man ls`
`ls /`

disk_time = Time.now - start

start = Time.now

(1..200000).each { |i| i*i/3.52345*i*i*i%34 }

cpu_time = Time.now - start

total = disk_time + cpu_time
puts "#{total},#{disk_time},#{cpu_time},#{start.strftime('%Y-%m-%d')},#{start.strftime('%H:%M:%S')}"

It uses ls and man to test wait for disk and then some made up maths to test the CPU. It’s not perfect but gives a good indication of performance.

Results
All times are in seconds, and you can download the full data to get a better picture. I’ve provided a summary and notes for each provider below.

Linde 512mb Tokyo (Zen)

Full Results

This is my second Linode VPS. I asked to be moved to a different node as the first one started fast when I got it but performance degraded (due to contention on the node?) within a few days. Nothing else is running on the VPS besides the script. Overall this is consistent, good performance in both CPU and disk. Latency to this VPS is around ~130ms from my ADSL in Sydney.

Octopus 650mb Australia (VMWare)

Full Results

Octopus is running a site for me with a significant cron job on the hour. I’ve therefore removed results collected on the hour. Despite running my live site, Octopus has the fastest average performance of all VPS tested. The higher max time could have been caused by load on my site. Octopus costs a bit more but is hosted in Australia so has very low latency of around 20ms from my ADSL in Sydney.

Amazon Small Instance 1.7gb Singapore (Zen)

Full Results

Amazon EC2 Small instances are now in the same ballpark cost as small VPS instances, when you go for high usage reserved. Many people think that EC2 disk is poor. However, from my tests (and experience) it is not super fast, but it is consistent and reliable. Amazon is also very generous with memory and provides other benefits like free transfer to S3. Where it falls down is processor speed, which, although fairly consistent, is about 50% slower than Linode and Octopus. Latency from Sydney ADSL is around 120ms.

Rails Playground 640mb USA (Virtuozzo)

Full Results

My RailsPlayground VPS is running various services and sites for me but none of them are high load. As you can see, the CPU performance is similar to Amazon and doesn’t vary too much. The problem is disk which varies hugely and can sometimes lead to unresponsive sites and services while waiting for IO. Latency from Sydney ADSL is around 200ms.

Conclusion
If you want a fast VPS with low latency in Australia and are willing to pay a bit more than the other providers listed, Octopus VPS will serve you well.

For lots of memory but slower CPU, Amazon small instance will be good.

For faster CPU but less memory, Linode is your best choice.

It’s worth testing out any new VPS and keeping an eye on performance over time. Contention on your node could change dramatically without you being aware of it, dramatically impacting performance of your VPS.

Rails Refactor, a small command line tool to make rails refactoring more fun, is now available as a gem. To use:
gem install rails_refactor

More info available on github.

During the RORO hack night last Wednesday, Ryan Bigg (@ryanbigg) and I worked on a Rails Refactor, something I’ve been meaning to get going for a long time.

How often have you wasted time doing renames in rails? Sure it’s hard to automate everything without understanding the code, but there sure are a lot of mechanical steps that you can easily automate. Ryan and I took on controller renames and got a fair way in the few hours we spent on the night.

Code is on github

To rename a controller:
$ rails_refactor.rb rename OldController NewController

• renames controller file & class name in file
• renames controller spec file & class name in file
• renames view directory
• renames helper file & module name in file
• updates routes

To rename a controller action:
$ rails_refactor.rb rename DummyController.old_action new_action

• renames controller action in controller class file
• renames view files for all formats

Looking to extend it with model renames, and then more complex refactoring.
If you like it, please fork and contribute 🙂

While comparing Dates and Times in Rails (both 2.3 and 3), I came across an odd behaviour:

>> Time.parse("Mon, 26 Jul 2010 9:59") == Date.new(2010, 7, 26)
=> false
>> Time.parse("Mon, 26 Jul 2010 10:00") == Date.new(2010, 7, 26)
=> true
>> Time.parse("Mon, 26 Jul 2010 10:01") == Date.new(2010, 7, 26)
=> false

Also

>> Date.new(2010, 7, 26) == Time.parse("Mon, 26 Jul 2010 10:00")
=> false (Rails 2.3)
=> nil (Rails 3)
>> Date.new(2010, 7, 26) == Time.parse("Mon, 26 Jul 2010 0:00")
=> false (Rails 2.3)
=> nil (Rails 3)


Tonight, we’ll be having the RORO hack night in the ThoughtWorks Sydney office, with a focus on open source projects (your own or contributing). A patch for this date/time behaviour might be an interesting area to pursue.