It’s been a few months since we‘ve started actively using ActiveMQ queue server in our project. For some time we had pretty weird problems with it and even started thinking about switching to something else or even writing our own queue server which would comply with our requirements. The most annoying problem was the following: some time after activemq restart everything worked really well and then activemq started lagging, queue started growing and all producer processes were stalling on push() operations. We rewrote our producers from Ruby to JRuby, then to Java and still – after some time everything was in a bad shape until we restarted the queue server.

So, long story short, after a lots of docs and source code reading we’ve found really interesting thing. There is a “feature” added in the recent ActiveMQ release …

I was invited to give a short introduction to Ruby on Rails at Tech Meetup in Edinburgh a couple of days ago. I’d been racking my brain for days on what to talk about — 15 minutes is too short for me to give a meaningful introduction to Rails — and eventually settled on telling a few stories.

The slides don’t make much sense on their own, so I’ve included the “script” of what I talked about too. I deviated quite a bit from the script as I got into it, so hopefully I should be able to provide audio (or, dread the thought, maybe even video) of the talk in due course.

Intro

I’m Graeme. I’m the Managing Director of Rubaidh Ltd, and have been developing Ruby on Rails applications professionally for 3 years now.

Telling Stories

To be honest, I didn’t know what my audience this evening was going to be like. I wasn’t sure if …

A compilation of news of interest:

Few months ago I’ve switched one of our internal projects from doing synchronous database saves of analytics data to an asynchronous processing using starling + a pool of workers. This was the day when I really understood the power of specialized queue servers. I was using database (mostly, MySQL) for this kind of tasks for years and sometimes (especially under a highly concurrent load) it worked not so fast… Few times I worked with some queue servers, but those were either some small tasks or I didn’t have a time to really get the idea, that specialized queue servers were created just to do these tasks quickly and efficiently.

All this time (few months now) I was using starling noticed really bad thing in how it works: if workers die (really die, or lock on something for a long time, or just start lagging) …

On a large data migration project that I am currently spearheading, we have a large installed userbase of over 2 million users running on a social networking engine. The schema has been redesigned from scratch, and code is being written to match the new schema, using the all-powerful MySQL database as the system to manage all that data.

Since this social network is global, we need good and reliable location information. The current location model is flawed and full of holes, so we have chosen AssemblySys‘ data to replace it.

We are not using AssemblySys’ schema, as we’ve rolled our own. I’ve designed our new schema to be hierarchial in nature, treating all locations on the planet as ‘nodes’ with a tree relationship, with “Earth” being the parent of all nodes. This model allows us to account for all countries and their idiosyncratic …

I had first seen the interesting Rails logo in a talk by Terry Chay, while I was at OSCON, a few months ago.

Now, my esteemed colleague Jay Pipes has it on his laptop. It seems they’re making stickers, even.

Otherwise, my next task is to revamp our Ruby content. Currently, it looks a little sad. It has to at least be as good as Using MySQL With Ruby, no?

TOTD #9 explained how to configure JDBC connection pooling for Rails application deployed on GlassFish v2. There are several benefits of using using the JDBC connection pools:

• No need to create a new database connection for each Rails instance.
• No need to specify your password in database.yml or create a hack to hide it.
• No garbage collection of connection after each use.

And because of the above mentioned (and other reasons) an improved application performance, scalability and efficiency.
The only way to deploy a Rails application on GlassFish v2 is to create a WAR file using …

If you deal with databases for a living, eventually you’ll come across cases where you’ll need to migrate a lot of data from one schema to another. I am not just talking about migrating from one different type of database to another, like from Oracle to MySQL, but from, for instance, a badly-designed schema to one more expertly crafted.

If there are minor differences between the source and target schema, this is a trivial affair. On the other hand, if the schema is completely different, this can be quite a challenge. Moreover, the database being migrated might represent a high-demand website that will need to be done with little or no downtime, with lots of planning and preparation to boot. You may be interacting with the application developers, the systems crew, and juggling tight deadlines as well.

Well, as you may have guessed, I have described some of the roles I now play at a leading social networking company. We are …

Today I’ve managed to finish initial version of our bounces-handler package we use for mailing-related stuff in Scribd.

Bounces-handler package is a simple set of scripts to automatically process email bounces and ISP‘s feedback loops emails, maintain your mailing blacklists and a Rails plugin to use those blacklists in your RoR applications.

This piece of software has been developed as a part of more global work on mailing quality improvement in Scribd.com, but it was one of the most critical steps after setting up reverse DNS records, DKIM and SPF.

The package itself consists of two parts:

• Perl scripts to process incoming email:
  • bounces processor — could be …

Launching a Startup in 3 Hours was a great talk given by Andrew Hyde (of techstars.org) and Gavin Doughtie (of Google). Both of the speakers are heavily involved in the recent trend of doing “Startup Weekends”, and techstars.org is an organization that hosts startup weekends all around the US (and I think internationally as well - Andrew mentioned one in Germany if I heard correctly).

The first half of the talk was about the general concept of a startup weekend, the problems it avoids (”we’ve been working for 9 months and haven’t launched anything”), the problems it brings up (”If you’re not using Java, you’re an idiot, so count me out!!”), and lots of details about how to organize, how to assign roles, and some common tools they use (like Basecamp and whatever your IM of choice is). There was also talk of legal issues, how (basically) to think about forming the company with the people involved, and decisions that need to …