WordPress is a popular platform for editing and publishing content for the web. In this tutorial, I’m going to walk you through how to build out a highly available (HA) WordPress deployment using Kubernetes. Read more
Note: this is Part 4 in a series on building highly resilient workloads. Parts 1, 2, and 3 are available already online.
In Part 4 of this series on running resilient workloads with Docker and Rancher, we take a look at service updates. Generally, service updates are where the risk of downtime is the highest. It doesn’t hurt to have a grasp of how deployments work in Rancher and the options available within.
For this post, instead of focusing on how to setup a continuous deployment/integration pipeline, we’ll instead focus on experimenting and learning with upgrades using rancher-compose files, and reference the great chain of articles by the awesome bloggers. We will skim over the Rancher CI/CD ebook for now, and sprinkle in enough theory to get us start using Rancher upgrades comfortably. Read more
Note: Rancher has come a long way since this was first published in June 2015. We’ve revised this post (as of August 2016) to reflect the updates in our enterprise container management service. Read on for the updated tutorial!
Rancher supports multiple orchestration engines for its managed environments, including Kubernetes, Mesos, Docker Swarm, and Cattle (the default Rancher managed environment). The Cattle environment is rich with features like stacks, services, and load balancing, and in this post, we’ll highlight common uses for these features. Overall, we’ll use Rancher and Docker to build a highly available and scalable WordPress environment, then we’ll cover how Rancher Catalog can be used to deploy complex stacks.
A scalable system is one that can handle an increasing number of requests without any impact on the response time and performance. On the other hand, High Availability describes a system that is continuously operational for a given period of time; the components of a high availability service often have failover components to continuously operate under any circumstances.
HA Deployment of WordPress
WordPress is one of the most popular CMSs out there, and can be configured with high availability and scalability by using specific components including:
Shared storage for the application files: GlusterFS.
Database Cluster backend: Percona XtraDB Cluster.
Decoupled application Docker image.
Load Balancer to distribute requests to the application containers.