path: root/aarch64/share/hadoop/httpfs/tomcat/RUNNING.txt

================================================================================
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
================================================================================

$Id: RUNNING.txt 1348600 2012-06-10 14:11:54Z kkolinko $

            ===================================================
            Running The Apache Tomcat 6.0 Servlet/JSP Container
            ===================================================

Apache Tomcat 6.0 requires a Java Standard Edition Runtime
Environment (JRE) version 5.0 or later.

=============================
Running With JRE 5.0 Or Later
=============================

(1) Download and Install a Java SE Runtime Environment (JRE)

(1.1) Download a Java SE Runtime Environment (JRE),
      release version 5.0 or later, from
      http://www.oracle.com/technetwork/java/javase/downloads/index.html

(1.2) Install the JRE according to the instructions included with the
      release.

      You may also use a full Java Development Kit (JDK) rather than just
      a JRE.


(2) Download and Install Apache Tomcat

(2.1) Download a binary distribution of Tomcat from:

      http://tomcat.apache.org/

(2.2) Unpack the binary distribution so that it resides in its own
      directory (conventionally named "apache-tomcat-[version]").

      For the purposes of the remainder of this document, the name
      "CATALINA_HOME" is used to refer to the full pathname of that
      directory.

NOTE:  As an alternative to downloading a binary distribution, you can
create your own from the Tomcat source code, as described in
"BUILDING.txt".  You can either

  a)  Do the full "release" build and find the created distribution in the
      "output/release" directory and then proceed with unpacking as above, or

  b)  Do a simple build and use the "output/build" directory as
      "CATALINA_HOME".  Be warned that there are some differences between the
      contents of the "output/build" directory and a full "release"
      distribution.


(3) Configure Environment Variables

Tomcat is a Java application and does not use environment variables. The
variables are used by the Tomcat startup scripts. The scripts use the variables
to prepare the command that starts Tomcat.

(3.1) Set CATALINA_HOME (required) and CATALINA_BASE (optional)

The CATALINA_HOME and CATALINA_BASE environment variables are used to
specify the location of Apache Tomcat and the location of its active
configuration, respectively.

The CATALINA_HOME environment variable should be set as defined in (2.2)
above. The Tomcat startup scripts have some logic to set this variable
automatically if it is absent (based on the location of the script in
Unixes and on the current directory in Windows), but this logic might not work
in all circumstances.

The CATALINA_BASE environment variable is optional and is further described
in the "Multiple Tomcat Instances" section below. If it is absent, it defaults
to be equal to CATALINA_HOME.


(3.2) Set JRE_HOME or JAVA_HOME (required)

The JRE_HOME variable is used to specify location of a JRE that is used to
start Tomcat.

The JAVA_HOME variable is used to specify location of a JDK. It is used instead
of JRE_HOME.

Using JAVA_HOME provides access to certain additional startup options that
are not allowed when JRE_HOME is used.

If both JRE_HOME and JAVA_HOME are specified, JRE_HOME is used.


(3.3) Other variables (optional)

Other environment variables exist, besides the four described above.
See the comments at the top of catalina.bat or catalina.sh scripts for
the list and a description of each of them.

One frequently used variable is CATALINA_OPTS. It allows specification of
additional options for the java command that starts Tomcat.

See the Java documentation for the options that affect the Java Runtime
Environment.

See the "System Properties" page in the Tomcat Configuration Reference for
the system properties that are specific to Tomcat.

A similar variable is JAVA_OPTS. It is used less frequently. It allows
specification of options that are used both to start and to stop Tomcat as well
as for other commands.

Do not use JAVA_OPTS to specify memory limits. You do not need much memory
for a small process that is used to stop Tomcat. Those settings belong to
CATALINA_OPTS.

Another frequently used variable is CATALINA_PID (on *nix platforms only). It
specifies the location of the file where process id of the forked Tomcat java
process will be written. This setting is optional. It will enable the
following features:

 - better protection against duplicate start attempts and
 - allows forceful termination of Tomcat process when it does not react to
   the standard shutdown command.


(3.4) setenv script (optional)

Apart from CATALINA_HOME and CATALINA_BASE, all environment variables can
be specified in the "setenv" script.

The script is named setenv.bat (Windows) or setenv.sh (*nix). It can be
placed either into CATALINA_BASE/bin or into CATALINA_HOME/bin. The file
has to be readable.

By default the setenv script file is absent. If the setenv script is
present both in CATALINA_BASE and in CATALINA_HOME, the one in
CATALINA_BASE is used.

For example, to configure the JRE_HOME and CATALINA_PID variables you can
create the following script file:

On Windows, %CATALINA_BASE%\bin\setenv.bat:

  set "JRE_HOME=%ProgramFiles%\Java\jre6"
  exit /b 0

On Unix, $CATALINA_BASE/bin/setenv.sh:

  JRE_HOME=/usr/java/latest
  CATALINA_PID="$CATALINA_BASE/tomcat.pid"

You cannot configure CATALINA_HOME and CATALINA_BASE variables in the
setenv script, because they are used to find that file.


(4) Start Up Tomcat

(4.1) Tomcat can be started by executing one of the following commands:

      %CATALINA_HOME%\bin\startup.bat         (Windows)

      $CATALINA_HOME/bin/startup.sh           (Unix)

   or

      %CATALINA_HOME%\bin\catalina.bat start  (Windows)

      $CATALINA_HOME/bin/catalina.sh start    (Unix)

(4.2) After startup, the default web applications included with Tomcat will be
      available by visiting:

      http://localhost:8080/

(4.3) Further information about configuring and running Tomcat can be found in
      the documentation included here, as well as on the Tomcat web site:

      http://tomcat.apache.org/


(5) Shut Down Tomcat

(5.1) Tomcat can be shut down by executing one of the following commands:

      %CATALINA_HOME%\bin\shutdown.bat       (Windows)

      $CATALINA_HOME/bin/shutdown.sh         (Unix)

   or

      %CATALINA_HOME%\bin\catalina.bat stop  (Windows)

      $CATALINA_HOME/bin/catalina.sh stop    (Unix)

==================================================
Advanced Configuration - Multiple Tomcat Instances
==================================================

In many circumstances, it is desirable to have a single copy of a Tomcat
binary distribution shared among multiple users on the same server.  To make
this possible, you can set the CATALINA_BASE environment variable to the
directory that contains the files for your 'personal' Tomcat instance.

When running with a separate CATALINA_HOME and CATALINA_BASE, the files
and directories are split as following:

In CATALINA_BASE:

 * bin  - Only the following files:

           * setenv.sh (*nix) or setenv.bat (Windows),
           * tomcat-juli.jar

          The setenv scripts were described above. The tomcat-juli library
          is documented in the Logging chapter in the User Guide.

 * conf - Server configuration files (including server.xml)

 * lib  - Libraries and classes, as explained below

 * logs - Log and output files

 * webapps - Automatically loaded web applications

 * work - Temporary working directories for web applications

 * temp - Directory used by the JVM for temporary files (java.io.tmpdir)


In CATALINA_HOME:

 * bin  - Startup and shutdown scripts

          The following files will be used only if they are absent in
          CATALINA_BASE/bin:

          setenv.sh (*nix), setenv.bat (Windows), tomcat-juli.jar

 * lib  - Libraries and classes, as explained below

 * endorsed - Libraries that override standard "Endorsed Standards"
              libraries provided by JRE. See Classloading documentation
              in the User Guide for details.

              By default this "endorsed" directory is absent.

In the default configuration the JAR libraries and classes both in
CATALINA_BASE/lib and in CATALINA_HOME/lib will be added to the common
classpath, but the ones in CATALINA_BASE will be added first and thus will
be searched first.

The idea is that you may leave the standard Tomcat libraries in
CATALINA_HOME/lib and add other ones such as database drivers into
CATALINA_BASE/lib.

In general it is advised to never share libraries between web applications,
but put them into WEB-INF/lib directories inside the applications. See
Classloading documentation in the User Guide for details.


It might be useful to note that the values of CATALINA_HOME and
CATALINA_BASE can be referenced in the XML configuration files processed
by Tomcat as ${catalina.home} and ${catalina.base} respectively.

For example, the standard manager web application can be kept in
CATALINA_HOME/webapps/manager and loaded into CATALINA_BASE by using
the following trick:

 * Copy the CATALINA_HOME/webapps/manager/META-INF/context.xml
   file as CATALINA_BASE/conf/Catalina/localhost/manager.xml

 * Add docBase attribute as shown below.

The file will look like the following:

  <?xml version="1.0" encoding="UTF-8"?>
  <Context docBase="${catalina.home}/webapps/manager"
    antiResourceLocking="false" privileged="true" useHttpOnly="true" >
  </Context>

See Deployer chapter in User Guide and Context and Host chapters in the
Configuration Reference for more information on contexts and web
application deployment.


================
Troubleshooting
================

There are only really 2 things likely to go wrong during the stand-alone
Tomcat install:

(1) The most common hiccup is when another web server (or any process for that
    matter) has laid claim to port 8080.  This is the default HTTP port that
    Tomcat attempts to bind to at startup.  To change this, open the file:

       $CATALINA_HOME/conf/server.xml

    and search for '8080'.  Change it to a port that isn't in use, and is
    greater than 1024, as ports less than or equal to 1024 require superuser
    access to bind under UNIX.

    Restart Tomcat and you're in business.  Be sure that you replace the "8080"
    in the URL you're using to access Tomcat.  For example, if you change the
    port to 1977, you would request the URL http://localhost:1977/ in your
    browser.

(2) The 'localhost' machine isn't found.  This could happen if you're behind a
    proxy.  If that's the case, make sure the proxy configuration for your
    browser knows that you shouldn't be going through the proxy to access the
    "localhost".

    In Firefox, this is under Tools/Preferences -> Advanced/Network ->
    Connection -> Settings..., and in Internet Explorer it is Tools ->
    Internet Options -> Connections -> LAN Settings.


====================
Optional Components
====================

The following optional components may be included with the Apache Tomcat binary
distribution. If they are not included, you can install them separately.

 1. Apache Tomcat Native library

 2. Apache Commons Daemon service launcher

Both of them are implemented in C language and as such have to be compiled
into binary code. The binary code will be specific for a platform and CPU
architecture and it must match the Java Runtime Environment executables
that will be used to launch Tomcat.

The Windows-specific binary distributions of Apache Tomcat include binary
files for these components. On other platforms you would have to look for
binary versions elsewhere or compile them yourself.

If you are new to Tomcat, do not bother with these components to start with.
If you do use them, do not forget to read their documentation.


Apache Tomcat Native library
-----------------------------

It is a library that allows to use the "Apr" variant of HTTP and AJP
protocol connectors in Apache Tomcat. It is built around OpenSSL and Apache
Portable Runtime (APR) libraries. Those are the same libraries as used by
Apache HTTPD Server project.

This feature was especially important in the old days when Java performance
was poor. It is less important nowadays, but it is still used and respected
by many. See Tomcat documentation for more details.

For further reading:

 - Apache Tomcat documentation

    * Documentation for APR/Native library in the Tomcat User's Guide

      http://tomcat.apache.org/tomcat-6.0-doc/apr.html

    * Documentation for the HTTP and AJP protocol connectors in the Tomcat
      Configuration Reference

      http://tomcat.apache.org/tomcat-6.0-doc/config/http.html

      http://tomcat.apache.org/tomcat-6.0-doc/config/ajp.html

 - Apache Tomcat Native project home

      http://tomcat.apache.org/native-doc/

 - Other projects

    * OpenSSL

      http://openssl.org/

    * Apache Portable Runtime

      http://apr.apache.org/

    * Apache HTTP Server

      http://httpd.apache.org/

To disable Apache Tomcat Native library:

 - To disable Apache Tomcat Native library when it is installed, or
 - To remove the warning that is logged during Tomcat startup when the
   library is not installed:

   Edit the "conf/server.xml" file and remove "AprLifecycleListener" from
   it.

The binary file of Apache Tomcat Native library is usually named

  - "tcnative-1.dll" on Windows
  - "libtcnative-1.so" on *nix systems


Apache Commons Daemon
----------------------

Apache Commons Daemon project provides wrappers that can be used to
install Apache Tomcat as a service on Windows or as a daemon on *nix
systems.

The Windows-specific implementation of Apache Commons Daemon is called
"procrun". The *nix-specific one is called "jsvc".

For further reading:

 - Apache Commons Daemon project

      http://commons.apache.org/daemon/

 - Apache Tomcat documentation

    * Installing Apache Tomcat

      http://tomcat.apache.org/tomcat-6.0-doc/setup.html

    * Windows service HOW-TO

      http://tomcat.apache.org/tomcat-6.0-doc/windows-service-howto.html

The binary files of Apache Commons Daemon in Apache Tomcat distributions
for Windows are named:

  - "tomcat6.exe"
  - "tomcat6w.exe"

These files are renamed copies of "prunsrv.exe" and "prunmgr.exe" from
Apache Commons Daemon distribution. The file names have a meaning: they are
used as the service name to register the service in Windows, as well as the
key name to store distinct configuration for this installation of
"procrun". If you would like to install several instances of Tomcat 6.0
in parallel, you have to further rename those files, using the same naming
scheme.