Apache Tomcat 7 Essentials

Table of Contents

Apache Tomcat 7 Essentials

Credits

About the Author

Acknowledgement

About the Reviewers

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Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Installation of Tomcat 7

History of Tomcat

Tomcat support matrix

Features and enhancements of Apache Tomcat 7

Web application memory leak detection and prevention

Servlet 3.0

Improved logging

Aliases

Installation of Tomcat 7

How to download the Tomcat software

Binary package

RPM/exe

Source

Prerequisites for the Tomcat 7 installation

Installation of Java

Installation of Java in Linux

Installation of Java in Windows

Configuration of OS environment variables

What is JAVA_HOME?

Setting the JAVA_HOME and PATH variable in Windows

Setting the global path variable in Windows

Setting the JAVA_HOME and the PATH environment variable in Linux

Installation of Apache Tomcat 7

Installation on a Windows environment

Installation on a Linux environment

Startup and shutdown of Tomcat services

Services in Windows

Services in Linux

Startup script

Shutdown script

Verification of Tomcat status

Common problems and troubleshooting in installation

Error: Permission denied for the Java binary

Error: Tomcat is not able to find JAVA_HOME

Error: Error in the logs showing port already in use

Summary

2. Configuration and Deployment

Configuration files and their usage

Configuration of Tomcat 7

DataSource configuration

JDBC

JNDI

DataSource

DataSource for Oracle

DataSource for MySQL

DataSource for PostgreSQL

Comparison of the datasource for common databases

Tomcat Manager configuration

Enabling the Tomcat Manager

Context path

Enabling the context path

GUI using the Tomcat Web Application Manager

Command-line configuration in server.xml

Deployment in Tomcat 7

Structure of the WebArchive

Archive Files

Exploded archive directories

Deployment operations

Types of deployment

Ways of application deployment in Tomcat 7

Common issues in deployment, configuration, and their troubleshooting

Summary

3. Performance Tuning

Performance tuning for Tomcat 7

Why we need performance tuning?

How to start performance tuning

Tomcat components tuning

Types of connectors for Tomcat 7

Java HTTP Connector

Java AJP Connector

APR (AJP/HTTP) Connector

Thread optimization for Tomcat 7

Shared thread pool (shared executor)

Dedicated thread pool

Shared thread pool versus dedicated thread pool

maxThreads

maxKeepAlive

JVM tuning

Why do we need to tune the JDK for Tomcat?

JMAP (Memory Map)

Syntax for jmap

How to increase the heap size in Tomcat 7

Garbage collection

How garbage collection works

JVM options

Standard options

Non-standard options

Parameters displayed in the logs for GC

SurvivorRatio

OS tuning

Summary

4. Integration of Tomcat with the Apache Web Server

User request flow (web/application level)

Why the Apache HTTP server

Installation of the Apache HTTP

Apache HTTP installation on Windows

How to monitor the Apache service

Installation of Apache HTTP on Linux (non-DOS environment)

Apache Portable Runtime

Installation of APR/APR-util

Apache Jserv protocol

Installation and configuration of mod_jk

Installation of mod_jk

Configuration of mod_jk in Apache

mod_proxy configuration

Comparison between mod_jk and mod_proxy

IIS integration with Tomcat 7

Prerequisites

Steps for installation

Common issues and troubleshooting for integration

Summary

5. Securing Tomcat 7

Tomcat Manager

Tomcat security permissions

catalina.properties

catalina.policy

System Code permissions

Catalina Code permissions (Tomcat core permission)

Web application permissions

tomcat-users.xml

server.xml

Enabling Tomcat Manager

How to enable the Tomcat Manager

Securing Tomcat 7 for production

Tomcat settings

Connector Port

Slimming of Tomcat application

Disable hot deployment

Non-Tomcat settings

Service as a separate user

Firewall

Password

SSL configuration on Tomcat 7

Types of SSL certificates

Process of installing SSL

Summary

6. Logging in Tomcat 7

JULI

Loggers, appenders, and layouts

Types of logging in Tomcat 7

Application log

Server log

Console log

Access log

Host manager

Types of log levels in Tomcat 7

Log4j

Log level for log4j

How to use log4j

Log level mapping

Values for Tomcat 7

Log analysis

Helpful commands for log analysis

Summary

7. Troubleshooting in Tomcat

Common problem areas for web administrators

How to troubleshoot a problem

Slowness issue in applications

How to solve slowness issues in Tomcat 7

User end troubleshooting

Web server troubleshooting

Tomcat 7 troubleshooting

Troubleshooting at the database level

Telnet DB server IP port

JVM analysis in the Tomcat instance

How to obtain a thread dump in Tomcat 7

Thread dump using Kill command

Thread dump using jstack

How to analyze the thread dump for Tomcat instance

Thread dump analysis using Samurai

Thread dump analysis using the Thread Dump Analyzer

Errors and their solutions

JVM (memory) issues

Out of Memory exception

OutOfMemoryError: PermGen space

Stack over flow exception

Database-related issues

Broken pipe exception

Timeout waiting for an idle object

Database connectivity exception

Web server benchmarking

ApacheBench

JMeter

Summary

8. Monitoring and Management of Tomcat 7

Different ways of monitoring

Monitoring setup for a web application and database server

Tomcat Manager in Tomcat 7

Monitoring in Tomcat 7

Summary of the Server Status of Tomcat 7

Complete Server Status of Tomcat 7

Application List

JVM

Connections on the HTTP port (8080)

Connections on the AJP

JConsole configuration on Tomcat 7

Remote JMX enabling

How to connect to the JConsole

Different tabs for the JConsole and their features

Memory overview

Threads overview

VM Summary and Overview

MBeans

Types of MBeans

Summary

9. Clustering in Tomcat 7

What is a cluster?

Benefits of clustering

Disadvantages of clustering

Clustering architecture

Vertical clustering

Advantages of vertical clustering

Disadvantages of vertical clustering

Horizontal clustering

Advantages of horizontal clustering

Disadvantages of horizontal clustering

Vertical clustering in Apache Tomcat 7

Installation of the Tomcat instance

Configuration of a vertical cluster

Configuration of instance 1

Configuration of instance 2

Apache web server configuration for vertical clustering

Horizontal clustering in Apache Tomcat 7

Installation of the Tomcat instance

Configuration of the cluster

Configuration of instance 1

Configuration of instance 2

Apache web server configuration for horizontal clustering

Testing of the clustered instance

Monitoring of Tomcat clustering

Summary

10. Tomcat Upgrade

Different types of environment

Development environment

Quality Assurance environment

Staging environment

Production environment

Life cycle of the upgrade

Tomcat upgrade from 6 to 7

Prerequisites for Tomcat 7

Installation of Tomcat 7 for the upgrade

Configuration of Tomcat 7

JVM configuration

Database connection settings

Application migration

Alias configuration

ITIL process implementation

Availability management

Capacity management

Service Transition

Summary

11. Advanced Configuration for Apache Tomcat 7

Virtual hosting

Name-based virtual hosting

IP-based virtual hosting

Virtual hosting in Tomcat 7

Hostname aliases

Multiple applications hosting on a single Tomcat 7 instance

Multiple Tomcat environments—Development/QA/Stage/Production

Tuning cache

Optimization of Tomcat 7

Running Tomcat 7 as a non privileged user

Summary

Index

Apache Tomcat 7 Essentials

Apache Tomcat 7 Essentials

Copyright © 2012 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: March 2012

Production Reference: 1160312

Published by Packt Publishing Ltd. Livery Place 35 Livery Street Birmingham B3 2PB, UK..

ISBN 978-1-84951-662-4

www.packtpub.com

Cover Image by Vinayak Chittar ( <[email protected]> )

Credits

Author

Tanuj Khare

Reviewers

Zeeshan Chawdhary

Ty Lim

Vidyasagar N V

Acquisition Editor

Usha Iyer

Lead Technical Editor

Susmita Panda

Technical Editor

Unnati Shah

Copy Editor

Laxmi Subramanian

Project Coordinator

Vishal Bodwani

Proofreader

Linda Morris

Indexer

Rekha Nair

Graphics

Valentina D'Silva

Manu Joseph

Production Coordinator

Alwin Roy

Cover Work

Alwin Roy

About the Author

Tanuj Khare has been a professional in IT for over six years. He is involved in process improvements using the ITIL framework and techniques such as Lean Six Sigma. He is MCSA and ITIL certified, and has expertise in handling critical production server issues. He also has a track record of dealing with many complex problems. His quick resolution to issues faced in the production environment has helped his team and clients in a big way.

Tanuj has Subject Matter Expertise (SME) in Tomcat, WebLogic, and JBoss server administration. His experience includes working with large-enterprise web hosting environments for J2EE containers with small teams, and his quick turnaround time gave on-time delivery. Apart from this, his technical expertise in Root Cause Analysis, Problem Management, Migration of enterprise applications, and upgrade of web application servers are commendable. Up to now, he has migrated more than 100 enterprise applications and upgraded J2EE web applications. He has also managed environments with over 1000 middleware instances.

Apart from work life, Tanuj enjoys playing Table Tennis and exploring new technologies. He is a good dancer. This is his first book.

Acknowledgement

I would like to express my gratitude to all the people who have helped me to make this book better. I thank Ranveer Chandel, who has helped me to provide high technical standards for this book.

I would like to thank Archana Kannoujia, who has patiently helped me to improve my writing style.

I would like to thank Mitesh Parikh and Giri Moturi for their support.

I would like to thank Usha Iyer, Vishal Bodwani, Susmita Panda, and everyone else at Packt Publishing for all their hard work to get this book published. A special thanks to Unnati Shah for her hard work and dedication to get this book published.

I would like to thank Ty Lim,Vidyasagar N V, and Zeeshan Chawdhury for providing their valuable guidance and support that helped me achieve the high technical standards.

And finally, I'd like to thank all my colleagues and friends, with whom I've worked throughout my career, for contributing to my professional development.

About the Reviewers

Zeeshan Chawdhary is the CTO of Wcities Inc., a location-based travel content provider, running technical operations from their Technical Headquarters in Mumbai.

He is a do-it-all and code-in-any-language guy, having worked with various technologies from 3D gaming to consumer websites, from iPhone apps to serving over 30 million hits over the Cloud.

He is currently writing two real-world-use books with Packt Publishing which are, iPhone Location Aware Applications by Example - Beginners Guide and Windows Phone 7.5 - Building Location Aware Applications.

He can be reached at imzeeshan on Twitter. He currently blogs at http://justgeeks.in.

I would like to thank the great people at Packt for letting me review this book. Special thanks to Vishal Bodwani, Susmita Panda, Leena Purkait, Amey Kanse, Alina Lewis, and a special mention for Mary Nadar, for having introduced me to the Packt family.

Ty Lim has been in the IT industry for over 15 years. He has worked for several startup companies in the mid 1990s and found himself working at several major corporations after his stint in Silicon Valley. He has worked in the following industries: Software Development, Consulting, Healthcare, Telecommunications, and Finance. He has experience in utilizing JBoss, Tomcat, and WebSphere middleware technologies. He holds a Bachelor of Science degree in Computer Science from the University of the Pacific, and is currently pursuing a Master of Science degree in CIS from Boston University.

He has also worked on IBM WebSphere Application Server v7.0 Security, Packt Publishing.

I would like to thank all my friends and family for their continued support. I am truly blessed to have such great support. It is because of all of you that I consider myself a very happy man.

Vidyasagar N V was interested in Computer Science since his early age. Some of his serious work in computers and computer networks began during his high school days. Later, he went to the prestigious institute of technology, Banaras Hindu University for his B.Tech. He has been working as a Software Developer, Data Expert, developing and building scalable systems since then. He has worked with a variety of 2nd, 3rd, and 4th generation languages. He has also worked with Flat files, Indexed files, Hierarchical databases, Network databases, Relational databases, NoSQL databases, Hadoop, and related technologies.

Currently, he is working as a Senior Developer at Ziva Software Pvt. Ltd, developing a big data-based structured data extraction technique from the Web and local information. He enjoys producing high-quality software, web-based solutions, and designing secure and scalable data systems.

He has also worked on PHP and MongoDB Web Development Beginner's Guide, Packt Publishing.

He can be reached at <[email protected]>.

I thank the almighty for giving me such a blessed life and thank my parents, Mr. N. Srinivasa Rao and Mrs. Latha Rao, and my family who supported and backed me throughout my life. I thank my friends and all those people who donated their time, effort, and expertise by participating in open source software projects. Also, thanks to Packt Publishing for selecting me as one of the technical reviewers for this wonderful book. It is my honor to be a part of this book.

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I would like to dedicate this book to my mom, Mrs. Shashi Khare and dad, Mr. Rajkumar Khare, for standing beside me during the writing of this book.

Without their support and encouragement, completing this book would have been a much more difficult task.

Preface

This book will help you resolve these issues and boost your confidence in handling Apache Tomcat 7 administration using the tips, tricks, and best practices used by various industry experts to maintain their middleware infrastructure. The best thing that the author did while designing the content is a practical solution, with a detailed description of why we are doing this solution.

Apache Tomcat (or Jakarta Tomcat, or simply Tomcat) is an open source servlet container developed by The Apache Software Foundation. The latest major stable release, Apache Tomcat version 7, implements the Servlet 3 and JavaServer Pages 2 specifications from the Java Community Process. It includes many additional features that make it a useful platform for developing and deploying web applications