ActiveRecord::StatementInvalid: Mysql::Error: Incorrect string value: ‘\xF0\x90\x8D\x83\xF0\x90…’ for column ‘content’ at row 1

上面的官方bug页面说要到mysql6.0才会解决。其实这个问题在mysql 5.5就解决了。5.5或以上的mysql都可以通过使用utf-16或utf8mb4等字符集解决这个问题。

不过使用ruby on rails的话可能需要一些额外的设置。

sudo gem install -v=2.3.9 rails
Password:
ERROR:  Could not find a valid gem 'rails' (= 2.3.9) in any repository
ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    too many connection resets (http://production.s3.rubygems.org/latest_specs.4.8.gz)

或

ERROR: While executing gem ... (Gem::DependencyError)
  Unable to resolve dependencies: rails requires activesupport (= 3.0.5), actionpack (= 3.0.5), activerecord (= 3.0.5), activeresource (= 3.0.5), actionmailer (= 3.0.5), railties (= 3.0.5), bundler (~> 1.0)

google了半天（期间google中短NNN次），才明天了现在使用rubygems 安装gem也得开代理了。。。

要使用加了代理的命令：

sudo gem install rails -p http://127.0.0.1:8118

现在rubygems好像只支持http代理。 如果你使用的是socks代理，可以通过Privoxy（支持linux和mac)这个软件来搞一个http代理 通道， 详细参看这个教程。

安装unicorn:

sudo gem install unicorn


创建网站配置文件(myproject是项目名称):

sudo mkdir /etc/unicorn
cd /etc/unicorn/
sudo nano /etc/unicorn/myproject.conf


内容如下：

RAILS_ROOT=/www/myproject
RAILS_ENV=production


在网站里再创建一个unicorn配置文件

nano /www/myproject/config/unicorn.rb


内容如下：

# Minimal sample configuration file for Unicorn (not Rack) when used
# with daemonization (unicorn -D) started in your working directory.
#
# See http://unicorn.bogomips.org/Unicorn/Configurator.html for complete
# documentation.
# See also http://unicorn.bogomips.org/examples/unicorn.conf.rb for
# a more verbose configuration using more features.

app_path = "/www/myproject"

listen 8080 # by default Unicorn listens on port 8080
worker_processes 2 # this should be >= nr_cpus
pid "#{app_path}/tmp/pids/unicorn.pid"
stderr_path "#{app_path}/log/unicorn.log"
stdout_path "#{app_path}/log/unicorn.log"


设置unicorn启动脚本：

sudo nano /etc/init.d/unicorn_init

脚本内容：

#!/bin/sh
#
# init.d script for single or multiple unicorn installations. Expects at least one .conf
# file in /etc/unicorn
#
# Modified by jay@gooby.org http://github.com/jaygooby
# based on http://gist.github.com/308216 by http://github.com/mguterl
#
## A sample /etc/unicorn/my_app.conf
##
## RAILS_ENV=production
## RAILS_ROOT=/var/apps/www/my_app/current
#
# This configures a unicorn master for your app at /var/apps/www/my_app/current running in
# production mode. It will read config/unicorn.rb for further set up.
#
# You should ensure different ports or sockets are set in each config/unicorn.rb if
# you are running more than one master concurrently.
#
# If you call this script without any config parameters, it will attempt to run the
# init command for all your unicorn configurations listed in /etc/unicorn/*.conf
#
# /etc/init.d/unicorn start # starts all unicorns
#
# If you specify a particular config, it will only operate on that one
#
# /etc/init.d/unicorn start /etc/unicorn/my_app.conf

set -e

sig () {
test -s "$PID" && kill -$1 `cat "$PID"`
}

ARGS="$1 $2"
start_stop $ARGS

注意将里面的/usr/bin/unicorn_rails 换成你系统中unicorn_rails程序的实际路径。

设置unicorn_init文件属性:

sudo chmod 755 /etc/init.d/unicorn_init


启动unicorn:

/etc/init.d/unicorn_init


修改nginx的配置文件，加入unicorn的代理设置：

upstream myproject_mongrel {
server 127.0.0.1:8080 fail_timeout=0;
}

这部分跟使用mongrel的类似的。

这样unicorn的设置就完成了。 刚设置好，感觉unicorn跟mongrel一样， 都是比较吃内存的， 一启动就占了50M. 不知道会不会也像mongrel一样把内存吃爆， 会得话得设置监控软件（如god）看住它。

Extreme Programming Explained describes Extreme Programming as being:
    * An attempt to reconcile humanity and productivity
    * A mechanism for social change
    * A path to improvement
    * A style of development
    * A software development discipline

Test-Driven Development
The goal of TDD is to write clean code that works.

What is Test-Driven Development?
Test-Driven Development (TDD) is a software development technique that involves repeatedly first writing a test case and then implementing only the code necessary to pass the test. Test-driven development is a method of designing software, not merely a method of testing.

In addition to normal “did it pass?” testing, you can go the opposite route. By testing your application where the weak points are, you can fix it before it ever becomes an issue.

Test-Driven Development Cycle
1. Add a test
In order to write a test, the developer must understand the specification and the requirements of the feature clearly.
2. Run all tests and see the new one fail
testing the tests
3. Write some code
It is important that the code written is only designed to pass the test; no further (and therefore untested) functionality should be predicted and ‘allowed for’ at any stage.

KISS
Keep It Simple, Stupid.
Everything should be made as simple as possible, but no simpler.
                    –Albert Einstein

You Ain’t Gonna Need It
‘You Ain’t Gonna Need It’(YAGNI), is a reminder for programmers that one should never add functionality until it is necessary.

4. Run the automated tests and see them succeed
5. Refactor code

Refactoring
A code refactoring is any change to a computer program which improves its readability or simplifies its structure without changing its results.
List of refactorings

    * Encapsulate Field(e.g. providing methods that can be used to read/write to/from the field rather than accessing the field directly.)
    * Extract Method (to turn part of a larger method into a new method. By breaking down code in smaller pieces, it is more easily understandable. This is also applicable to functions)
    * Generalize Type (to making more general or more abstract some subset of the traits of a specific type. An example of generalizing a type would be moving a method from a child to a parent class for common use by all the parent class’ children, not just the original child.)
    * Pull Up (moving a method from a Subclass into a Superclass. )
    * Push Down (moving a method from a SuperClass into a SubClass.)
    * Rename Method (changing the name of a method into a new one that better reveals its purpose).

The cycle is then repeated, starting with another new test to push forward the functionality.

"Test-Driven Development Mantra" is known as red/green/refactor where red means fail and green is pass.

Benefits
By focusing on the test cases first, one must imagine how the functionality will be used by clients (in this case, the test cases). Therefore, the programmer is only concerned with the interface and not the implementation.
It allows a programmer to focus on the task at hand as the first goal is to make the test pass.
Ensuring that all written code is covered by a test.

Limitations
A test-driven development is only as good as its tests.

Reference
http://en.wikipedia.org/wiki/Test-driven_development
http://en.wikipedia.org/wiki/You_Ain%27t_Gonna_Need_It
http://en.wikipedia.org/wiki/Refactoring

Related Resources
Test::Unit – Ruby Unit Testing Framework
A Guide to Testing the Rails
Test Driven Design for Ruby and Rails
Ruby, Rails, Test::Rails Cheat Sheet