Our production environment includes the following:
- 3 frontends who serve our website
- 2 database backends (Master-Slave, replication)
- 1 mixed which runs httpd and database for adserving
Our development environment is a single server running both database and httpd, configuration-wise we have different workspaces for everyone setup and our VC is subversion. Staging is rather simple too - it runs on one of the frontends.
Database changes
Initially we spent a lot of time on the database design and it seems to have really paid off. We haven't changed anything major in five months now. Most of the changes we deploy are on the frontend. Now, so far we run all the changes to the database manually and I always wrote a small script to revert.
If I had more of those, I'd use Doctrine and Migrations here. I've never actually had the chance to use them in production but I've played with those extensively already and they seem very powerful.
Deployment
So whenever we deploy a new version we create a tag of the code which we check out on staging, then go through a couple lists of checks etc. and then we deploy the code on the production frontends. For doing all of the deployment, I have a couple tasks setup in Capistrano.
Check out this sample capfile:
role :www, "web01", "web02", "web03"
role :web, "web01", "web02", "web03", "web04"
role :db, "db01", "db02"
desc "Deploy sites"
task :deploy, :roles => :www do
run "cd /usr/www/website && sudo svn --username=deploy --password=foo update"
end
Capistrano also allows you to run any other command without defining a task:
cap invoke COMMAND="uptime" ROLES=web
(Requires the role "web" to be setup. See example above.)
Coding style and documentation
We pretty much adhere to the PEAR Coding standard, which we check using PHP_CodeSniffer (phpcs). When I say pretty much, I mean that I forked the sniffs provided and added a few exceptions of my own gusto.
On top of coding style, phpcs checks on inline documentation as well. This documentation is created by phpDocumentor in the end.
CI
I have both of those tools setup in our CI-server (continuos-integration), which is phpUnderControl using the above and CruiseControl, phpUnit, Xdebug (a couple code metrics...), etc..
unit-testing is something we currently lack. But what we do right now is that with each bug we find in our parsing engine (we parse text into certain formats), we write a test to make sure it doesn't come back. I've also written some basic tests to check the URL-routing and the internal XMLRPC API but this is really subject to improvement. We employ both phpUnit-style tests and phpt as well.
The CI-server builds a new version a couple times per day, generates graphs, docs and all kinds of reports.
On top of all of the tools mentioned, we also use Google Apps (primarily for email) and keep a Google Sites wiki with all other documentation. For example, deployment procedure, QA test lists, etc..
