Drupal 6 stack

Below is the list of services available in !app_external stack.

Service Container Description
Nginx + PHP
The main container with Nginx as a web server. Nginx uses an asynchronous event-driven approach to handling requests which provides more predictable performance under high loads.

Available PHP versions for Drupal 6 are PHP 5.3 and 5.6.
Cache storage
Memcached is a well-known and mature memory caching system. The easiest way to improve performance of Drupal 6 (or Pressflow) is to connect an external in-memory cache storage.

Use Memcache API and Integration module to integrate it with Drupal
Search engine
Apache Solr
The de facto standard search engine for full-text or faceted search. Providing distributed search and index replication, Solr is designed for scalability and fault tolerance.

Reverse caching proxy
Varnish is an HTTP accelerator designed for content-heavy dynamic web sites as well as heavily consumed APIs. As HTTP accelerator works well in pair with most popular web servers.

Use Varnish module to integrate it with Drupal
MariaDB is a drop-in replacement for MySQL intended to remain free under the GNU GPL. It has multiple speed improvements comparing to MySQL and has a very active developers community.

Mail server
It's a simple and lightweight open-source SMTP server that delivers outbound emails from your apps.

Mail catcher
MailHog is an email testing tool for developers to catch and review all outbound emails from your dev/staging instances where you don't need to send real emails.

Database management
Simple tool to handle the administration of MariaDB/MySQL with the use of a web browser. It can perform various tasks such as creating, modifying or deleting databases, tables, fields or rows; executing SQL statements;

We regularly update stacks by releasing newer versions of stacks, such updates can include security updates and performance improvements.