Resin is a web server and Java application server from Caucho Technology. In addition to Resin, Resin Pro is available for enterprise and production environments with a license. Resin supports the Java EE standard as well as a mod_php/PHP like engine called Quercus. While Resin is free for use in production, Resin Pro includes optimizations such as:
Although a Java-based server, key pieces of Resin's core networking are written in highly optimized C. Caucho states Java is the layer that allows Resin to be "full featured" while C provides the speed. Resin, which was released in 1999, predates Apache Tomcat, and is one of the most mature application servers and web servers.
Product features
Resin Pro has been engineered to include:
Dynamic Clustering- Locking was replaced with non-locking atomic operations, cleared contention bottlenecks, improved the async/epoll performance, and reduced thread overhead to handle 100,000 requests per second.
Cloud Support- Elastic cluster members can be added or removed using a single command. Cluster topology, load balancing, caching, messaging and management automatically adapt to dynamic servers.
Compiled PHP on the JVM- Improves performance, scalability and security of PHP applications by allowing PHP code to directly call Java Objects.
Security though Open SSL integration- A comprehensive security framework for application authentication, authorization and transport level SSL based security.
Smart Software Load balancer- Application load is shared among resources automatically to balance them.
Proxy cache- Faster application performance is possible with Java caching by saving the results of long calculations and reducing database load and application response time.
Scalability
Elastic Clustering / Cloud support
*3rd generation clustering optimized for Virtualization 2.0, EC2 and OpenStack deployments
Resin's market share is small in the grand scheme of Java Application Servers, but some high traffic sites use it, such as Toronto Stock Exchange, Salesforce.com, Condé Nast, CNET. NetCraft's February 2012 Survey stated Resin grew to 4,700,000 sites; Resin was the only Java-based web server mentioned. A 2012-page on a Caucho wiki site describes a test procedure with results showing that tested 0k, 1K, 8K and 64K byte files. At every level Resin matched or exceeded nginx web server performance.
Quercus
Quercus is a Java-based implementation of the PHP language that is included with Resin. According to a slideshow presented by Emil Ong, to a San Francisco Java Meetup Group in April 2008 pertaining to Resin 3.1, an essential difference in the operation of Quercus between the Resin Open Source and the Resin Professional editions is that in Resin Professional the PHP is compiled to Java bytecode whereas in the open source version PHP is executed by an interpreter. Caucho states that Quercus is faster than standard PHP although this is only true for the JIT-compiled version in Resin Professional. Quercus ships with Resin.
Licensing
One license covers all components of the Resin architecture. Resin is provided in both an open source GPL license and a Pro version with enhancements for enterprises.
