Apache Tomcat Training

Lesson 1 • Tomcat Architecture Overview

Examines the layered component model: Server, Service, Connector, Engine, Host, and Context. Understanding this hierarchy is prerequisite for all configuration chapters.

Lesson 2 • Tomcat Manager and Host Manager

Introduces the built-in web-based management interfaces for deploying and monitoring applications. Learners configure manager roles and access the GUI and text interfaces.

Lesson 3 • Directory Structure and Key Files

Maps the Tomcat installation layout including bin, conf, lib, logs, webapps, and work directories. Familiarity with this structure underpins every configuration task ahead.

Lesson 4 • What Is Apache Tomcat

Defines Tomcat as an open-source servlet container implementing Java Servlet and JSP specifications. Establishes context for all subsequent configuration and deployment topics.

Lesson 1 • Logging Configuration with logging.properties

Configures Java Util Logging handlers, levels, and file rotation in logging.properties. Proper logging is essential for troubleshooting covered in later chapters.

Lesson 2 • Connector Configuration and Protocols

Configures HTTP/1.1, HTTP/2, and AJP Connectors including thread pools and timeout settings. Connector tuning directly impacts throughput and latency under load.

Lesson 3 • Global and Application web.xml

Explains the global conf/web.xml defaults and per-application WEB-INF/web.xml overrides. Covers servlet mappings, MIME types, session config, and welcome files.

Lesson 4 • Understanding server.xml

Dissects every major element in server.xml: Server, Service, Connector, Engine, Host, and Valve. Changes here directly affect network ports, virtual hosts, and request routing.

Lesson 1 • Manual Deployment via Manager

Demonstrates WAR upload, context path assignment, and undeployment through the Manager web interface and text API. Reinforces Manager setup from Chapter 1.

Lesson 2 • Deployment with Ant and Maven Plugins

Integrates Tomcat Maven Plugin and Ant tasks into build pipelines for automated deployment. Enables CI/CD workflows built upon in the advanced chapters.

Lesson 3 • Context Path and Virtual Hosting

Configures multiple Host elements and context paths to serve several applications from one Tomcat instance. Builds on server.xml knowledge from Chapter 2.

Lesson 4 • Auto-Deploy and Hot Deploy

Explains autoDeploy and deployOnStartup attributes and how Tomcat watches the appBase directory. Learners configure and test automatic deployment and reloading behaviour.

Lesson 1 • Tomcat Class Loader Hierarchy

Maps Tomcat's Common, Catalina, Shared, and WebApp class loaders and their visibility rules. Correct placement of JARs in lib directories depends on this hierarchy.

Lesson 2 • Managing Shared Libraries

Covers placing JARs in CATALINA_HOME/lib for sharing across applications and avoiding duplication. Reduces memory footprint and prevents version conflicts between deployed apps.

Lesson 3 • Java Class Loading Fundamentals

Reviews parent-delegation model and bootstrap, extension, and system class loaders as a baseline. This foundation is required to understand Tomcat's custom loader hierarchy.

Lesson 1 • Realms and Authentication Mechanisms

Configures UserDatabaseRealm, JDBCRealm, JNDIRealm, and DataSourceRealm for user authentication. Realm selection determines how credentials are stored and validated.

Lesson 2 • TLS and HTTPS Configuration

Configures JSSE and OpenSSL-based TLS Connectors, keystore creation, and certificate installation. Enables encrypted communication required for production deployments.

Lesson 3 • Server Hardening Best Practices

Removes default applications, disables unused connectors, and restricts server information disclosure. Reduces attack surface on internet-facing Tomcat instances.

Lesson 4 • Role-Based Access Control

Applies security-constraint, auth-constraint, and user-data-constraint elements in web.xml to restrict URL patterns. Enforces least-privilege access across application resources.

Lesson 1 • JVM Tuning for Tomcat

Sets heap size, garbage collection strategy, and JVM flags in CATALINA_OPTS for optimal performance. JVM tuning complements connector settings to reduce GC pauses and OOM errors.

Lesson 2 • Caching and Compression

Enables static resource caching via DefaultServlet and HTTP response compression via Connector attributes. Reduces bandwidth and improves perceived response times for end users.

Lesson 3 • Benchmarking and Profiling

Uses Apache JMeter and Java profilers to measure throughput, latency, and resource usage under load. Profiling results guide the tuning decisions covered in earlier sections.

Lesson 4 • Thread Pool and Executor Configuration

Configures shared Executor elements and per-Connector thread limits to handle concurrent requests efficiently. Thread pool sizing directly determines maximum request concurrency.

Lesson 1 • Tomcat Clustering Architecture

Explains the Cluster element, membership discovery, and channel communication components. This architecture overview is required before configuring replication in the next section.

Lesson 2 • Session Management Fundamentals

Covers HTTP session lifecycle, session ID generation, and cookie vs. URL rewriting tracking. Understanding session mechanics is prerequisite for replication and persistence topics.

Lesson 3 • Session Persistence Strategies

Configures FileStore and JDBCStore Manager elements to persist sessions across restarts. Persistence prevents session loss during planned maintenance and unexpected restarts.

Lesson 4 • Load Balancer Integration

Integrates Tomcat with Apache HTTP Server mod_proxy_balancer and mod_jk for sticky session routing. Builds on AJP Connector knowledge from Chapter 2.

Lesson 1 • JMX Monitoring and MBeans

Enables JMX remote access and uses JConsole or VisualVM to inspect Tomcat MBeans at runtime. JMX provides real-time visibility into connectors, thread pools, and application state.

Lesson 2 • Log Analysis and Diagnostics

Interprets catalina.out, localhost logs, access logs, and GC logs to identify errors and anomalies. Log correlation across files accelerates root-cause identification.

Lesson 3 • Diagnosing Memory Leaks

Identifies classloader memory leaks, static reference leaks, and thread-local leaks common in web applications. Uses heap dumps and Tomcat leak detection listeners to pinpoint causes.

Lesson 4 • Thread Deadlock and Stuck Thread Detection

Captures and analyses thread dumps to identify deadlocks and stuck threads blocking request processing. StuckThreadDetectionValve automates detection before user-visible failures occur.