Book Image

Mastering Symfony

Book Image

Mastering Symfony

Overview of this book

In this book, you will learn some lesser known aspects of development with Symfony, and you will see how to use Symfony as a framework to create reliable and effective applications. You might have developed some impressive PHP libraries in other projects, but what is the point when your library is tied to one particular project? With Symfony, you can turn your code into a service and reuse it in other projects. This book starts with Symfony concepts such as bundles, routing, twig, doctrine, and more, taking you through the request/response life cycle. You will then proceed to set up development, test, and deployment environments in AWS. Then you will create reliable projects using Behat and Mink, and design business logic, cover authentication, and authorization steps in a security checking process. You will be walked through concepts such as DependencyInjection, service containers, and services, and go through steps to create customized commands for Symfony's console. Finally, the book covers performance optimization and the use of Varnish and Memcached in our project, and you are treated with the creation of database agnostic bundles and best practices.
Table of Contents (17 chapters)
Mastering Symfony
Credits
About the Author
About the Reviewers
Index

Definition of a cache


A cache is a temporary place that stores contents in order to be served faster when they are needed. Considering that we already have a permanent place on disk to store our web contents (templates, codes, and database tables), a cache sounds like a duplicate storage.

That is exactly what they are. They are duplicates and we need them because, in return for consuming extra space to store the same data, they provide a very fast response to some requests. So this is a very good trade-off between storage and performance.

To give you an example of how good this deal can be, consider the following image. On the left-hand side, we have a usual client/server request/response model, and let's say that the response latency is two seconds and there are only 100 users who hit the same content per hour.

On the right-hand side, however, we have a cache layer that sits between the client and server. What it basically does is it receives the same request and passes it to the server. The...