Tomcat Web Application Manager How To

Table of Contents

Introduction

In many production environments it is very useful to have the capability to manage your web applications without having to shut down and restart Tomcat. This document is for the HTML web interface to the web application manager.

The interface is divided into six sections:

  • Message - Displays success and failure messages.
  • Manager - General manager operations like list and help.
  • Applications - List of web applications and commands.
  • Deploy - Deploying web applications.
  • Diagnostics - Identifying potential problems.
  • Server Information - Information about the Tomcat server.

Message

Displays information about the success or failure of the last web application manager command you performed. If it succeeded OK is displayed and may be followed by a success message. If it failed FAIL is displayed followed by an error message. Common failure messages are documented below for each command. The complete list of failure messages for each command can be found in the manager web application documentation.

Manager

The Manager section has three links:

  • List Applications - Redisplay a list of web applications.
  • HTML Manager Help - A link to this document.
  • Manager Help - A link to the comprehensive Manager App HOW TO.

Applications

The Applications section lists information about all the installed web applications and provides links for managing them. For each web application the following is displayed:

  • Path - The web application context path.
  • Display Name - The display name for the web application if it has one configured in its "web.xml" file.
  • Running - Whether the web application is running and available (true), or not running and unavailable (false).
  • Sessions - The number of active sessions for remote users of this web application. The number of sessions is a link which when submitted displays more details about session usage by the web application in the Message box.
  • Commands - Lists all commands which can be performed on the web application. Only those commands which can be performed will be listed as a link which can be submitted. No commands can be performed on the manager web application itself. The following commands can be performed:
    • Start - Start a web application which had been stopped.
    • Stop - Stop a web application which is currently running and make it unavailable.
    • Reload - Reload the web application so that new ".jar" files in /WEB-INF/lib/ or new classes in /WEB-INF/classes/ can be used.
    • Undeploy - Stop and then remove this web application from the server.

Start

Signal a stopped application to restart, and make itself available again. Stopping and starting is useful, for example, if the database required by your application becomes temporarily unavailable. It is usually better to stop the web application that relies on this database rather than letting users continuously encounter database exceptions.

If this command succeeds, you will see a Message like this:

OK - Started application at context path /examples

Otherwise, the Message will start with FAIL and include an error message. Possible causes for problems include:

  • Encountered exception

    An exception was encountered trying to start the web application. Check the Tomcat logs for the details.

  • Invalid context path was specified

    The context path must start with a slash character, unless you are