Tutorial: Highly Available WordPress (Part I)
Unfortunately, things fail from time to time, including our applications’ servers. A connectivity problem at the datacenter, a natural disaster or a hardware issue can render our blog offline. Since we cannot predict the future nor prevent failures from happening, we are leveraging the power of the cloud in order to save ourselves from them and keep our services working despite them: we’re designing our infrastructure with failure in mind so nothing fails.
It’s important that our platform isn’t dependant on any specific component in order to work or else service will be interrupted should that component fail. We have to identify our platform’s components and isolate them as much as possible: if our front web servers depend on some specific database server, then everything in our application depends on it and it becomes a dreadful single point of failure. On the other hand, if we design in a way in which we don’t depend on specific machines, we can have more than one of them serving each of our application’s layers and we won’t see any issues as a result of a single machine failing.
via Tutorial: Highly Available WordPress (Part I) | Celingest Blog – Feel the Cloud.