Sun Microsystems introduced GlassFish as an open-source application server for the Java EE platform, marking its debut in 2005. The GlassFish Project unveiled its first version supporting the Java EE 5 specification on May 4, 2006. GlassFish is currently available in versions 3.0.1, 3.1, 3.2, and 4.0, focusing on features such as clustering, virtualization, and seamless integration with Coherence and various Oracle technologies. Renowned for its speed, security, scalability, and as a leading Java EE container, GlassFish offers a robust foundation for enterprise applications.

GlassFish is distributed under two free software licenses: the Common Development and Distribution License (CDDL) and the GNU General Public License (GPL), making it a freely available software. It also receives commercial support, providing an enterprise-level application server to the open-source community and building upon the legacy of the Sun Java System Application Server.

Apache Tomcat, also known as Jakarta Tomcat or simply Tomcat, represents another significant player in the open-source ecosystem, specializing in Java Servlet and JavaServer Pages technologies. Developed under the Java Community Process, Tomcat enjoys widespread popularity within the Java community. Most applications designed for Tomcat can also operate on GlassFish without modifications, thanks to their compatibility. Tomcat boasts native support for both Windows and Unix environments, enhancing its platform integration capabilities.

GlassFish vs. Tomcat Difference

GlassFish is a prominent figure in the realm of enterprise application servers, often mentioned alongside other heavyweight servers such as JBoss and WebSphere. These servers are known for their comprehensive support of the Enterprise JavaBeans (EJB) standard, offering a plethora of advanced features ready for immediate use. This makes them particularly suitable for large-scale enterprise applications that demand robust, high-performance backends. GlassFish, in particular, stands out for its complete Java EE platform support, which includes:

  1. EJB Container: Enables the execution of Enterprise JavaBeans, facilitating the development of scalable, transactional, and multi-tier Java applications;
  2. Web Container: Supports Servlets and JavaServer Pages (JSP), allowing for the creation and hosting of dynamic web applications and services;
  3. Application Client Container: Provides a runtime environment for application client components, running on the client machine and enabling a rich, interactive user interface;
  4. Resource Adapter Container: Supports connectivity to external systems and resources, such as databases and messaging systems, through the Java EE Connector Architecture (JCA);
  5. Management and Security: GlassFish incorporates robust management and security features, including monitoring, logging, authentication, and authorization mechanisms, ensuring applications are not only performant but also secure.

In contrast to servers like Tomcat, which is primarily a web container focusing on Servlets and JSPs, GlassFish offers a comprehensive suite of Java EE containers. This enables developers to leverage a full range of Java EE technologies beyond just web applications, including EJBs, web services, and more, making it a versatile choice for developing and deploying enterprise applications. This integrated support for various Java EE specifications means that developers can use GlassFish to build and deploy highly scalable, secure, and sophisticated applications that require a broad set of Java EE features.

Web Container Feature Alignment: GlassFish vs. Tomcat

The GlassFish community has worked to incorporate Tomcat’s popular features into GlassFish, while also introducing unique capabilities not found in Tomcat. This effort has led to a comprehensive comparison of features between GlassFish versions 2 and 3 and Tomcat, covering a wide array of functionalities from basic support for Tomcat valves, mod_jk, WebDAV, and CGI, to advanced Java EE certification, sophisticated administrative consoles, and robust integration tools.

Notably, GlassFish version 3 expands its feature set with native jRuby/Rails deployment, rapid redeployment capabilities, verification tools, and a modular architecture based on OSGi, among others. These enhancements underscore GlassFish’s commitment to flexibility, efficiency, and a comprehensive support system for Java EE applications.

GlassFish vs. Tomcat Performance Comparison

A performance comparison between GlassFish and Tomcat underlines the differences in their handling of web applications. Utilizing JMeter as a testing tool, the comparison revealed Tomcat’s performance with an average response time and throughput over a specific number of samples, highlighting its capability to handle Java-based web applications efficiently.

Conversely, GlassFish showcased superior performance metrics, with higher average response times and throughput, indicating its robustness and ability to manage more demanding Java EE applications with greater efficiency and fewer errors.

This performance evaluation illustrates the distinctive strengths and applications of each server, providing valuable insights for developers and organizations in selecting the appropriate server for their specific Java EE application requirements.

Table: Feature and Performance Comparison

Feature/AspectGlassFishTomcat
Java EE SupportFull support, including EJB, JPA, JSF, JMS, CDILimited to Servlets, JSPs, and basic Java EE features
Management & SecurityAdvanced management, monitoring, and security featuresBasic security and management features
PerformanceHigher throughput and response times for Java EE appsEfficient for web applications with faster setup
ScalabilityDesigned for large-scale enterprise applicationsSuitable for smaller scale applications and microservices
FlexibilitySupports a broad range of Java EE technologiesFocused on web applications, more straightforward to manage
Community & SupportCommercial support available, robust communityLarge open-source community, wide adoption

This table summarizes the key differences between GlassFish and Tomcat, helping developers and organizations make informed decisions based on their specific project needs.

Conclusion

Choosing between GlassFish and Tomcat for a project involves weighing the distinct features and performance capabilities each server offers. GlassFish shines in environments that demand full Java EE support, offering a comprehensive set of containers for EJBs, web services, and more. This makes it an ideal choice for large-scale, enterprise-level applications that require extensive back-end functionality, robust security, and scalability. On the other hand, Tomcat serves best when projects are focused primarily on web applications utilizing Servlets and JSPs. Its lighter weight, simplicity, and ease of use make it a popular choice for developers looking for a straightforward but efficient server to deploy Java-based web applications.

The performance comparison further delineates their suitable domains: Tomcat for applications where high throughput and low latency are critical with simpler Java EE needs, and GlassFish for more complex, enterprise-grade applications requiring the full spectrum of Java EE features. Ultimately, the choice between GlassFish and Tomcat hinges on the specific requirements of the project, including the needed Java EE features, performance demands, and the scale of the application being developed. Both servers have their place in the Java ecosystem, and selecting the right one can significantly impact the success and scalability of your project.