opportunity__cost

AWS Free Usage Tier (Per Month):

• 750 hours of Amazon EC2 Linux Micro Instance usage (613 MB of memory and 32-bit and 64-bit platform support) – enough hours to run continuously each month*
• 750 hours of an Elastic Load Balancer plus 15 GB data processing*
• 10 GB of Amazon Elastic Block Storage, plus 1 million I/Os, 1 GB of snapshot storage, 10,000 snapshot Get Requests and 1,000 snapshot Put Requests*
• 5 GB of Amazon S3 storage, 20,000 Get Requests, and 2,000 Put Requests*
• 30 GB per of internet data transfer (15 GB of data transfer “in” and 15 GB of data transfer “out” across all services except Amazon CloudFront)*
• 25 Amazon SimpleDB Machine Hours and 1 GB of Storage**
• 100,000 Requests of Amazon Simple Queue Service**
• 100,000 Requests, 100,000 HTTP notifications and 1,000 email notifications for Amazon Simple Notification Service**

In addition to these services, the AWS Management Console is available at no charge to help you build and manage your application on AWS.

Amazon is giving away the small Linux instances for free starting the 1st of November for 1 year. Sounds like a decent bait for developers.

What's Wrong with MySQL?

Our primary motivation for moving away from MySQL is the increasing difficulty of building a high performance, write intensive, application on a data set that is growing quickly, with no end in sight. This growth has forced us into horizontal and vertical partitioning strategies that have eliminated most of the value of a relational database, while still incurring all the overhead.

Relational database technology can be a blunt instrument and we're motivated to find a tool that matches our specific needs closely. Our domain area, news, doesn't exact strict consistency requirements, so (according to Brewer's theorem) relaxing this allows gains in availability and partition tolerance (i.e. operations completing, even in degraded system states). We're confident that our engineers can implement application level consistency controls much more efficiently than MySQL does generically.

As our system grows, it's important for us to span multiple data centers for redundancy and network performance and to add capacity or replace failed nodes with no downtime. We plan to continue using commodity hardware, and to continue assuming that it will fail regularly. All of this is increasingly difficult with MySQL.

An interesting blog post from from Digg's VP of Engineering, briefly describing their need and chosen solution.

Nothing new for those who are interested in NoSQL space, because Digg was contributing a decent amount of development time with Cassandra and shared its experience with developers.

What's also a good thing, that Digg decided to open source everything that they do and will do with Cassandra, making it more solid product.

Random Ruby and Rails tips.
This blog is dedicated to deliver short, interesting and practical tidbits of the Ruby language and Ruby on Rails framework.

Nice collection of tips and tricks on Ruby (+oR). Not that big (about 20 so far?), but nice thing to keep in bookmarks.

Flickr is somewhat unique in that it uses a code repository with no branches; everything is checked into head, and head is pushed to production several times a day. This works well for bug fixes that we want to go out immediately, but presents a problem when we’re working on a new feature that takes several months to complete. How do we solve that problem? With flags and flippers!

I really like this approach. It's definitely far from perfect, but gives a feeling of tech importance and value that is live. Every single moment.

Conclusion: worth considering for your project.

Rails in a Nutshell

This is the draft of upcoming O'Reilly book. Feel free to read and comment. :)