Redmine

Redmine is a flexible project management web application. Written using Ruby on Rails framework, it is cross-platform and cross-database.

Redmine is open source and released under the terms of the GNU General Public License v2 (GPL).

Overview

• Multiple projects support
• Flexible role based access control
• Flexible issue tracking system
• Gantt chart and calendar
• News, documents & files management
• Feeds & email notifications
• Per project wiki
• Per project forums
• Time tracking
• Custom fields for issues, time-entries, projects and users
• SCM integration (SVN, CVS, Git, Mercurial, Bazaar and Darcs)
• Issue creation via email
• Multiple LDAP authentication support
• User self-registration support
• Multilanguage support
• Multiple databases support

http://www.redmine.org/

nested relations in ActiveRecord

class State < ActiveRecord::Base
 has_many :cities
end

class City < ActiveRecord::Base
 has_many :streets
 belongs_to :state
end

class Street < ActiveRecord::Base
 has_many :houses
 belongs_to :city
end

class House < ActiveRecord::Base
 belongs_to :street
end

How do you get all of the Houses in virginia?

Well, you could do this:

virginia.cities.collect{|c| c.streets}.flatten.uniq.collect{|s| s.houses}.flatten.uniq

... but that's epically lame. It looks like shit and produces an metric ton of queries and as a result is highly inefficient.

How about this:

House.find(
 :all,
 :include => {:street => {:city => :state}},
 :conditions => {'states.id' => virginia.id}
)

This is a single query with joins where appropriate, and it's a finder on House which is what you're getting anyways. Makes sense, no?

http://joshsharpe.com/archives/56

Understanding the MySQL forks

But in the distributed revision control world we live in, it's never really that simple. Here are some other notes:

• XtraDB is an InnoDB fork and "mostly" only a storage engine. It has a future in MariaDB and Drizzle, but may not make it into MySQL (about to be owned by Oracle, who also owns InnoDB).
• OurDelta collects more patches than just the Percona patches, and enables the PBXT storage engine. There's also a repository of OurDelta for 5.1 - binaries just aren't out yet.
• Like XtraDB, PBXT has a future in Drizzle, MariaDB and *maybe* also MySQL (Oracle may be more friendly towards PBXT than XtraDB, but Oracle is not known to be friendly so who knows!). I left PBXT absent from the diagram for not having much of a lineage with previous MySQL releases (flames welcome if you disagree).
• XtraDB draws a lot from the Google patches for MySQL/InnoDB (not present on the diagram either).
• Drizzle is now incompatible with everything else in MySQL-land terms (replication, partitioning, etc), and they're happy to be. In storage engine terms, they're still compatible though, which leads me to describe Drizzle as a completely new "userland", with storage engine options still remaining very similar.
• MariaDB is both a new storage engine (Maria) and a userland "delta" of MySQL. I call it a delta since it is trying to keep binary-format compatibility with MySQL wherever it can. This means that it makes a good retrofit, but it limits what they can do without changing things like the .frm format, etc.
• The InnoDB plugin has a weird history. Oracle announced it as an optional replacement for the 5.1 InnoDB but not much has become of it since introduction. I would have expected 5.4 to be based off the plugin, but it's not (at least at this point).
• MySQL is the real loser in the direction the patches are moving. While all other forks are free to share amongst themselves (where compatible) and take from MySQL, MySQL will only accept a patch if the author signs a Contributor's License Agreement. They need to do this - otherwise they can't sell OEM copies, which still make a large chunk of sales. Until recently, MySQL didn't accept any InnoDB patches unless they came downstream from Oracle, and Oracle keeps InnoDB development as a closely guarded secret - which makes influencing it very difficult.

http://mtocker.livejournal.com/50931.html

JSGI

JSGI is a web server interface specification for JavaScript, inspired by Ruby’s Rack (http://rack.rubyforge.org/) and Python’s WSGI (http://www.wsgi.org/). It provides a common API for connecting JavaScript frameworks and applications to webservers.

Jack is a collection of JSGI compatible handlers (connect web servers to JavaScript web application/frameworks), middleware (intercept and manipulate requests to add functionality), and other utilities (to help build middleware, frameworks, and applications).

http://jackjs.org/

Narwhal

Narwhal is a cross-platform, multi-interpreter, general purpose JavaScript platform. It aims to provide a solid foundation for building JavaScript applications, primarily outside the web browser. Narwhal includes a package manager, module system, and standard library for multiple JavaScript interpreters. Currently Narwhal’s Rhino support is the most complete, but other engines are available too.

Narwhal’s standard library conforms to the ServerJS standard. It is designed to work with multiple JavaScript interpreters, and to be easy to add support for new interpreters. Wherever possible, it is implemented in pure JavaScript to maximize reuse of code among engines.

Combined with Jack, a Rack-like JSGI compatible library, Narwhal provides a platform for creating server-side JavaScript web applications and frameworks such as Nitro.

http://narwhaljs.org/

DB Charmer – ActiveRecord Connection Magic Plugin

DbCharmer is a simple yet powerful plugin for ActiveRecord that does a few things:

1. Allows you to easily manage AR models’ connections (switch_connection_to method)
2. Allows you to switch AR models’ default connections to a separate servers/databases
3. Allows you to easily choose where your query should go (on_* methods family)
4. Allows you to automatically send read queries to your slaves while masters would handle all the updates.
5. Adds multiple databases migrations to ActiveRecord

OurDelta

OurDelta produces enhanced builds for MySQL 5.0 and builds for MariaDB 5.1, on common production platforms. James Purser of Open Source On The Air describes OurDelta as “a new distribution for MySQL”.

http://ourdelta.org/