Links Administrative Apps Internal Servlets Realm Implementations | | Overview |
| Introduction |
The purpose of this specification is to define high level requirements
for administrative applications that can be used to manage the operation
of a running Tomcat 4.0 container. A variety of Access Methods
to the supported administrative functionality shall be supported, to
meet varying requirements:
- As A Scriptable Web Application - The existing
Manager web application provides a simple HTTP-based
interface for managing Tomcat through commands that are expressed
entirely through a request URI. This is useful in environments
where you wish to script administrative commands with tools that
can generate HTTP transactions.
- As An HTML-Based Web Application - Use an HTML presentation
to provide a GUI-like user interface for humans to interact with the
administrative capabilities.
- As SOAP-Based Web Services - The operational commands to
administer Tomcat are made available as web services that utilize
SOAP message formats.
- As Java Management Extensions (JMX) Commands - The operational
commands to administer Tomcat are made available through JMX APIs,
for integration into management consoles that utilize them.
- Other Remote Access APIs - Other remote access APIs, such
as JINI, RMI, and CORBA can also be utilized to access administrative
capabilities.
Underlying all of the access methods described above, it is assumed
that the actual operations are performed either directly on the
corresponding Catalina components (such as calling the
Deployer.deploy() method to deploy a new web application),
or through a "business logic" layer that can be shared across all of the
access methods. This approach minimizes the cost of adding new
administrative capabilities later -- it is only necessary to add the
corresponding business logic function, and then write adapters to it for
all desired access methods.
The current status of this functional specification is
PROPOSED. It has not yet been discussed and
agreed to on the TOMCAT-DEV mailing list.
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| Implementation Requirements |
The implementation of this functionality shall conform to the
following requirements:
- To the maximum extent feasible, all administrative functions,
and the access methods that support them, shall run portably
on all platforms where Tomcat 4 itself runs.
- In a default Tomcat distribution, all administrative capabilities
shall be disabled. It shall be necessary for a system
administrator to specifically enable the desired access methods
(such as by adding a username/password with a specific role to
the Tomcat user's database.
- Administrative functions shall be realized as direct calls to
corresponding Catalina APIs, or through a business logic layer
that is independent of the access method used to initiate it.
- The common business logic components shall be implemented in
package
org.apache.catalina.admin.
- The common business logic components shall be built as part of the
standard Catalina build process, and made visible in the
Catalina class loader.
- The Java components required for each access method shall be
implemented in subpackages of
org.apache.catalina.admin.
- The build scripts should treat each access method as optional,
so that it will be built only if the corresponding required
APIs are present at build time.
- It shall be possible to save the configured state of the running
Tomcat container such that this state can be reproduced when the
container is shut down and restarted.
- Adminstrative commands to start up and shut down the overall
Tomcat container are out of scope for the
purposes of these applications. It is assumed that other
(usually platform-specific) mechanisms will be used for container
startup and shutdown.
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| Dependencies |
| Environmental Dependencies |
The following environmental dependencies must be met in order for
administrative applications to operate correctly:
- For access methods that require creation of server sockets, the
appropriate ports must be configured and available.
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| Container Dependencies |
Correct operation of administrative applications depends on the
following specific features of the surrounding container:
- To the maximum extent feasible, Catalina components that offer
direct administrative APIs and property setters shall support
"live" changes to their operation, without requiring a container
restart.
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| External Technologies |
The availability of the following technologies can be assumed
for the implementation and operation of the various access methods
and the corresponding administrative business logic:
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| Functionality |
| Properties of Administered Objects |
Functional requirements for administrative applications are specified
in terms of Administered Objects, whose definitions and detailed
properties are listed here. In general,
Administered Objects correspond to components in the Catalina architecture,
but these objects are defined separately here for the following reasons:
- It is possible that the administrative applications do not expose
every possible configurable facet of the underlying components.
- In some cases, an Administered Object (from the perspective of an
administrative operation) is realized by more than one Catalina
component, at a finer-grained level of detail.
- It is necessary to represent the configuration information for a
component separately from the component itself (for instance, in
order to store that configuration information for later use).
- It is necessary to represent configuration information (such as
a Default Context) when there is no corresponding component instance.
- Administered Objects, when realized as Java classes, will include
methods for administrative operations that have no correspondence
to operations performed by the corresponding actual components.
It is assumed that the reader is familiar with the overall component
architecture of Catalina. For further information, see the corresponding
Developer Documentation. To distinguish names that are used as both
Administered Objects and Components, different
font presentations are utilized. Default values for many properties
are listed in [square brackets].
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| Supported Administrative Operations |
The administrative operations that are available are described in terms
of the corresponding Administered Objects (as defined above), in a manner
that is independent of the access method by which these operations are
requested. In general, such operations are relevant only in the context
of a particular Administered Object (and will most likely be realized as
method calls on the corresponding Administered Object classes), so they
are organized based on the currently "focused" administered object.
The available Supported Operations are documented
here.
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| Access Method Specific Requirements |
Scriptable Web Application
An appropriate subset of the administrative operations described above
shall be implemented as commands that can be performed by the "Manager"
web application. FIXME - Enumerate them.
In addition, this web application shall conform to the following
requirements:
- All request URIs shall be protected by a security constraint that
requires security role
manager for processing.
- The default user database shall not contain any
user that has been assigned the role
manager.
HTML-Based Web Application
The entire suite of administrative operations described above shall be
made available through a web application designed for human interaction.
In addition, this web application shall conform to the following
requirements:
- Must be implemented using servlet, JSP, and MVC framework technologies
described under "External Technologies", above.
- Prompts and error messages must be internationalizable to multiple
languages.
- Rendered HTML must be compatible with Netscape Navigator (verson 4.7
or later) and Internet Explorer (version 5.0 or later).
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