JBoss (now WildFly) and Glassfish represent two distinct approaches to Java EE implementation. JBoss uses a modular classloading system with AS7+ architecture, while Glassfish follows a more traditional monolithic design with OSGi-based modularity.

// JBoss module descriptor example
module com.example.myapp {
    requires javaee.api;
    exports com.example.myapp.services;
}

// Glassfish deployment descriptor snippet
<glassfish-application>
    <module>
        <web>
            <web-uri>myapp.war</web-uri>
            <context-root>/app</context-root>
        </web>
    </module>
</glassfish-application>

In recent benchmarks (Java EE 8 implementations):

• JBoss EAP 7 averages 12% faster request processing for REST endpoints
• Glassfish 5 shows 18% better memory efficiency in long-running processes
• JBoss handles 23% more concurrent WebSocket connections

Feature	JBoss EAP 7	Glassfish 5
MicroProfile Support	Full 2.0 implementation	Partial 1.4 support
Hot Deployment	Exploded deployment only	Full hot deploy
Clustering	mod_cluster	GMS/HADB
Management API	REST/DMR	REST/AMX

Datasource configuration differs significantly:

// JBoss datasource
<datasource jndi-name="java:jboss/datasources/ExampleDS">
    <connection-url>jdbc:h2:mem:test</connection-url>
    <driver>h2</driver>
    <security>
        <user-name>sa</user-name>
    </security>
</datasource>

// Glassfish datasource
<resources>
    <jdbc-connection-pool name="ExamplePool">
        <property name="URL" value="jdbc:h2:mem:test"/>
    </jdbc-connection-pool>
    <jdbc-resource jndi-name="jdbc/ExampleDS" pool-name="ExamplePool"/>
</resources>

IDE integration varies considerably:

• JBoss Tools plugin for Eclipse provides complete server adapters
• Glassfish has better NetBeans integration with visual admin console
• IntelliJ IDEA supports both but with more advanced JBoss debugging

When moving between servers:

// Common migration issues
1. JNDI naming differences (java:global vs java:jboss)
2. Security realm configurations
3. Transaction timeout handling
4. JPA second-level cache implementations

Key ecosystem differences:

• JBoss has broader commercial support options (Red Hat)
• Glassfish reference implementation gets earlier Java EE spec updates
• JBoss community provides more third-party extensions

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JBOSS (now WildFly) implements the full Java EE specification with additional enterprise extensions, while Glassfish serves as Oracle's reference implementation. The key architectural divergence appears in their modularity approaches:

// JBOSS module configuration example
<subsystem xmlns="urn:jboss:domain:ee:4.0">
    <global-modules>
        <module name="org.apache.log4j" slot="main"/>
    </global-modules>
</subsystem>

// Glassfish equivalent in domain.xml
<applications>
    <module name="log4j" type="jar" location="/lib/log4j.jar"/>
</applications>

Recent benchmarks (2023) show WildFly 27 outperforms Glassfish 7 in throughput tests:

• JAX-RS requests: WildFly 18% faster
• JMS messaging: Glassfish shows better stability under 10k+ concurrent connections
• Memory footprint: Glassfish requires 15-20% more heap for equivalent workloads

JBOSS provides superior integration with Red Hat's middleware stack:

// JBOSS Fuse integration example
@RouteConfiguration(routeId = "jms2rest")
public class JmsToRestRoute extends RouteBuilder {
    public void configure() {
        from("jms:queue:orders")
        .to("rest:post:orders/api?host=192.168.1.100");
    }
}

Glassfish offers tighter Oracle Database integration:

// Glassfish Oracle UCP configuration
<resource-adapter-config 
  resource-adapter-name="oracle-ucp-ra" 
  thread-pool-ids="connector-thread-pool">
    <property name="URL" value="jdbc:oracle:thin:@localhost:1521:ORCL"/>
</resource-adapter-config>

WildFly's modular architecture translates better to cloud-native deployments:

# WildFly Dockerfile snippet
FROM quay.io/wildfly/wildfly:27.0.1.Final
COPY --chown=jboss:jboss target/app.war /opt/jboss/wildfly/standalone/deployments/
CMD ["/opt/jboss/wildfly/bin/standalone.sh", "-b", "0.0.0.0"]

Glassfish requires additional tuning for Kubernetes:

# Glassfish memory settings for containers
ENV MEM_MAX_RAM_PERCENTAGE=80.0
ENV MEM_XSS=256k
ENV MEM_MAX_METASPACE_SIZE=192m

When moving between servers, pay attention to these differences:

// JNDI lookup pattern comparison
// JBOSS
InitialContext ctx = new InitialContext();
DataSource ds = (DataSource) ctx.lookup("java:/MyDS");

// Glassfish
DataSource ds = (DataSource) ctx.lookup("jdbc/MyDS");

JBOSS implements Elytron security subsystem:

<security-domain name="AppDomain">
    <authentication>
        <login-module code="LdapExtended" flag="required">
            <module-option name="java.naming.provider.url" value="ldap://ldap.example.com:389"/>
        </login-module>
    </authentication>
</security-domain>

Glassfish uses older but more standardized JAAS configuration:

<auth-realm name="ldap-realm" classname="com.sun.enterprise.security.auth.realm.ldap.LDAPRealm">
    <property name="directory" value="ldap://ldap.example.com:389"/>
    <property name="base-dn" value="dc=example,dc=com"/>
</auth-realm>