Resin is a web server and Java application server from Caucho Technology. In addition to Resin (GPL), 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 (GPL) is free for use in production, Resin Pro includes optimizations such as: built-in caching public/private/or hybrid clustering advanced administration health system HTTP session replication distributed cache replication auto-recovery & diagnostic reports
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 Session Replication Load balancing Distributed Cache Memcached wire protocol for Couchbase Server like caching
Development
Class compilation
JIT Profiling and heap analysis
No required
JUnit support
Web Admin
DevOps support via CLI and REST control of Resin
Apache Ant/Maven/Ivy integration
IDE integration
Flexible project management
Logging
Production Ready
Reliability
Server Monitoring
Deployment / Cloud deployment
Versioned deployment
Merge paths
Troubleshooting aids
Server health reports, baselining and post mortem reporting
Throttling
App Server
Java EE Web Profile certified, Java CDI standard Java dependency injection similar to Guice and Spring, part of Java EE Transaction support
Web Server
Static files/JSP/Servlet/JSF
Extensible access logging
URL rewriting
Proxy caching (similar to Squid) Gzip compression
Virtual Hosts
Comet/Server push
WebSocket
mod-php like support via Quercus
FastCGI
Usage
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 (parent company of Wired, Vogue, GQ), 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 (empty HTML page), 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 (from Caucho), 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 stated in 2007 that Quercus was faster than standard PHP 5 (PHP 8 with JIT is much faster than older PHP versions; PHP 5 is no longer supported) 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.