As of today I’m no longer working for LivingSocial and I’m looking for the next thing to work on. Since my family is in Toronto and I have an apartment (mortgage) here, I’m not looking to relocate and currently looking for something remote (I have 7+ years of remote work experience) or something local in Toronto.
For more information on my background, please check my Github profile, my linkedin profile or the resume section on this blog. If you need to contact me, feel free to use any channels listed on the contacts page.
Update: After a few initial interviews I’d like to update this post with a bit more details on what I’m looking for in the new position.
First of all, I’m really not sure I want to be yet another ops engineer working on “everything ops” in my next company. If I’d be to join a company as a regular ops engineer, I’d prefer it to be a clearly defined role with a clear focus on some set of challenging problems. I’m honestly tired of setting up cacti/nagios/chef at this point and would like the job to be a little bit more challenging.
Though even more I’m interested in being able to make strategic technical decisions for an operations team and apply my experience and knowledge for solving challenging tasks with a dedicated team of ops engineers. This could be anything from a tech ops team lead role (in a medium/large companies) to a director of technical operations (in a small-to-medium sized startups).
Update: Ok, I’ve found a new job – I work for Swiftype now!
This week, after 3 months in the works, we’ve finally released version 1.7.0 of DbCharmer ruby gem – Rails plugin that significantly extends ActiveRecord’s ability to work with multiple databases and/or database servers by adding features like multiple databases support, master/slave topologies support, sharding, etc.
New features in this release:
- Rails 3.0 support. We’ve worked really hard to bring all the features we supported in Rails 2.X to the new version of Rails and now I’m proud that we’ve implemented them all and the implementation looks much cleaner and more universal (all kinds of relations in rails 3 work in exactly the same way and we do not need to implement connection switching for all kinds of weird corner-cases in ActiveRecord).
- Forced Slave Reads functionality. Now we could have models with slaves that are not used by default, but could be turned on globally (per-controller, per-action or in a block). This is a new feature that brings our master/slave routing capabilities to a really new level – we could now use it for a really mission-critical models on demand and not be afraid of breaking major functionality of our applications by switching them to slave reads.
- Lots of changes were made in the structure of our code and tests to make sure it would be much easier for new developers to understand DbCharmer internals and make changes in its code.
Along with the new release we’ve got a brand new web site. You can find much better, cleaner and, most importantly, correct documentation for the library on the web site. We’ll be adding more examples, will try to add more in-depth explanation of our core functions, etc.
If you have any questions about the release, feel free to ask them in our new mailing list: DbCharmer Users Group.
For more updates on our releases, you can follow @DbCharmer on Twitter.
Having a reverse-proxy web cache as one of the major infrastructure elements brings many benefits for large web applications: it reduces your application servers load, reduces average response times on your site, etc. But there is one problem every developer experiences when works with such a cache – cached content invalidation.
It is a complex problem that usually consists of two smaller ones: individual cache elements invalidation (you need to keep an eye on your data changes and invalidate cached pages when related data changes) and full cache purges (sometimes your site layout or page templates change and you need to purge all the cached pages to make sure users will get new visual elements of layout changes). In this post I’d like to look at a few techniques we use at Scribd to solve cache invalidation problems.
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Back in November 2009 I was working on a project to port Scribd.com code base to Rails 2.2 and noticed that some old plugins we were using in 2.1 were abandoned by their authors. Some of them were just removed from the code base, but one needed a replacement – that was an old plugin called acts_as_readonlyable that helped us to distribute our queries among a cluster of MySQL slaves. There were some alternatives but we didn’t like them for one or another reasons so we’ve decided to go with creating our own ActiveRecord plugin, that would help us scale our databases out. That’s the story behind the first release of DbCharmer.
Today, six months after the first release of the gem and we’ve moved it to gemcutter (which is now the official gems hosting) and we’re already at version 1.6.11. The gem was downloaded more than 2000 times. There are (at least) 10+ large users that rely on this gem to scale their products out. And (this is the most exciting) we’ve added tons of new features to the product.
Here are the main features added since the first release:
- Much better multi-database migrations support including default migrations connection changing.
- We’ve added ActiveRecord associations preload support that makes it possible to move eager loading queries to the same connection where your finder queries go to.
- We’ve improved ActiveRecord’s query logging feature and now you can see what connections your queries executed on (and yes, all those improvements are colorized :-)).
- We’ve added an ability to temporary remap any ActiveRecord connections to any other connections for a block of code (really useful when you need to make sure all your queries would go to some non-default slave and you do not want to mess with all your models).
- The most interesting change: we’ve implemented some basic sharding functionality in ActiveRecord which currently is being used in production in our application.
As you can see now DbCharmer helps you to do three major scalability tasks in your Rails projects:
- Master-Slave clusters to scale out your Rails models reads.
- Vertical sharding by moving some of your models to a separate (maybe even dedicated) servers and still keep using AR associations
- Horizontal sharding by slicing your models data to pieces and placing those pieces into different databases and/or servers.
So, If you didn’t check DbCharmer out yet and you’re working on some large rails project that is (or going to be) facing scalability problems, go read the docs, download/install the gem and prove them that Rails CAN scale!
Today I’m proud to announce the first public release of our ActiveRecord database connection magic plugin: DbCharmer.
DB Charmer – ActiveRecord Connection Magic Plugin
DbCharmer is a simple yet powerful plugin for ActiveRecord that does a few things:
- Allows you to easily manage AR models’ connections (
- Allows you to switch AR models’ default connections to a separate servers/databases
- Allows you to easily choose where your query should go (
on_* methods family)
- Allows you to automatically send read queries to your slaves while masters would handle all the updates.
- Adds multiple databases migrations to ActiveRecord
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