Django Deployment Workshop

So you’ve written a Django site… now what? Writing the application is just the beginning; now you’ve got to put it into production! In this hands-on workshop we’ll walk through the creation of a full Django deployment environment running on a cluster of (virtual) machines.

This class will introduce students to a wide variety of technologies, including, Apache, Fabric, nginx, mod_wsgi, memcached, PostgreSQL, pgpool, pg_standby, and more.

By the end of the class, each student will have created an environment featuring:

• Multiple levels of caching and load balancing.
• Multiple web application servers.
• Redundant replicated database servers.

We’ll create this whole stack on virtual machines, and students will be able to take home a complete copy of all the deployment configuration for future review at their leisure.

Note: the example application used in this class with be a Django site, and the class assumes at least a moderate comfort level with Django. However, the tools and techniques apply just as well to other Python web frameworks, so users of other tools will likely be able to follow along fairly easily.

Outline:

• Introducing our example application.
• Overview of where we’re going.
• Very brief intro to EC2 and S3.
• Exercise: run our first VM.

• What’s an application server?
• Introducing mod_wsgi
• Configuring Apache and mod_wsgi
• Exercise: deploy the application under mod_wsgi.
• Exercise: initial load test.

• Why a separate database server?
• Configuring PostgreSQL
• Exercise: deploy PostgreSQL.

• What’s Fabric?
• Writing fabfiles.
• Integrating fabfiles into Django applications.
• Exercise: deploy using Fabric

• Why multiple web servers?
• “Shared nothing”
• Dealing with medi
• Load balancers
• Introducing nginx
• Using nginx as a reverse proxy
• Exercise: deploy onto multiple machines.
• Exercise: crash a web server.

• Local caching vs. dedicated caching.
• Introducing memcached
• Using memcached with Django.
• Exercise: deploy with multiple cache servers.

• Why connection middleware?
• Introducing pgpool.
• Configuring pg_pool and Django.
• Exercise: deploy pg_pool

• Redundancy strategies
• Warm standby with pg_standby
• Exercise: configure warm standby
• Exercise: fall over to the slave

Final exercise: load testing – how’d we do?