Pressflow

Pressflow makes Drupal scaleable and resilient:

If your requirement is for hi-traffic or hi-demand web-sites then Pressflow is the answer, its Drupal  with speed.  

What is Pressflow:

Pressflow is Drupal, but it is extended to work with Varnish and Memcache plus Apache / PhP extras and database handlers for Mysql replication and performance 'tweaking'.

Every version of Pressflow is fully compatible with the same major Drupal version. therefore Pressflow 6 is compatible with all Drupal 6 modules. Pressflow 6 can also integrate with the SimpleTest system from Drupal 7 and the CDN (Content Delivery Network) support patch.

How does Pressflow work:

It works by integrating Drupal with a number of Open Source applications designed to improve web-page delivery eg. Apache, Varnish and Memcache.

Pressflow, Varnish, Memcache  and the LAMP stack (Linux, Apache, Mysql and Php ) all need to be configured and fine tuned to work in harmony and maximise the systems response. Performance ‘tweaking’ is normally ongoing and is based on the behaviour of the environment (the web sites and servers) over a time period, load demands and traffic analysis.

Our server and LAMP team can provide support with LAMP stack and Pressflow, Varnish and Memcahe tuning. We can also provide infrastructure recommendations or system audits of your installation.

Pressflow with Varnish:

Pressflow and Varnish deliver pages for unauthenticated users (not logged in) up to 1000’s of times faster than normal Drupal. It does by caching (storing for quick delivery) Drupal pages, assets and style sheets. When a browser makes a request, rather than processing Drupal, Varnish delivers the page immediately from its store (cache).  Web Pages, Asset (images etc) and CSS style sheets storage life times (expires) are all configurable ensuring that the correct content is delivered in the fastest possible time and are kept up-to-date and fresh.         

Pressflow with Memcache:

Unlike Varnish, Memcache stores elements of HTML (web pages), Drupal blocks and  views, database calls (SQL Queries) etc, enabling the delivery of dynamic content to authenticated users (logged-in). When a  request arrives the various page elements held in memory are joined and delivered as a single page. This method ensures the fastest possible response for dynamic  content whilst maintaining real-time data flows.   

Pressflow and resilience:

Pressflow can work with load balancers and  MYSQL Replication.  Load Balancer direct web-page traffic to specfic 'Apache' servers and Mysql Replication handles SQL calls and data syncronization between a Mysql Master server and a Mysql Slave. The Mysql Slave can be anywhere and called on should disaster hit the Master. It can also be used to deliver content over a multi-server network where the load-balancer distributes page requests to a number of servers and can isolate a server from the pool when problems arrive.

Pressflow scalability and NAS (Network-attached storage):

Using  NAS with Pressflow enables multiple page servers to share assets and a scaleable delivery infrastructure is created. Replacing the Drupal pages servers  ‘Files’ directory with  a single NAS mounting point enables a number of ‘Page’ servers to share a single ‘files’ directory ensuring that assets and content are immediately available to the entire system. Load balancers can used to allocate requests between servers and distributing requests over the entire system to spread the load.  This approach, used in conjunction with Varnish / Memcache, removes the limit to the number of pages which can be delivered at any one time. It provides Fast, Reliable Drupal content and is completely scaleable and robust. 

What you get with Pressflow: 

Pressflow gives Drupal Speed, Saleability, and Resilience.

We can help with the deployment and implementation of Drupal for demanding applications and sites, by using Pressflow, and the configuration and tuning of the LAMP STACK, Pressflow, Varnish, and Memcache either on your servers or ours to get the most out of Pressflow.  

Aleady Got Pressflow:

If you’ve already have Pressflow depolyed we can help with tuning and configuration to get the best out of your installation.  If you need a Module or Theme our developers are use to creating code and designs with performance, and security built in. We have created code for some of the best known corporate and household names in the country and can help you.