Sorry for the late reply. I have had these notes for days and just
keep forgetting to post them. Notes in line...
On Apr 23, 2006, at 8:07 PM, Aaron Mulder wrote:
Apache Geronimo Principles & Goals
=== Principles ===
How about stating these with heading words like "Competitive",
"Flexiable", and "Just Works" that tie into the Goals section. This
is kind of the executive summary...
* Be competitive with other application servers
* Be flexible to include exactly what a user wants (lightweight,
heavyweight,
I know it is the same thing, but I'd state it as "only what a user
wants and nothing more"
product integration, customized admin tools, etc.). Make it
easy to get
there from the initial download.
flexiable enough to adapt to (almost) any operating environment. I
thinking of university environments where 90% of the server install
is shared and students get their own apps and logs dirs. Another one
is ISVs with shared installations for customers.
* Be the IntelliJ of app servers (it thinks like you do, works
like you
expect, etc.) -- alternately, be the OS X of app servers (easy
to use and
even the hard stuff "just works")
I would state this one as "Just Works" or "Simple". The server
should work as an average-joe would expect. If I throw a jar into
web-inf/lib and restart my web app it should get picked up (it
doesn't currently).
=== Goals ===
Flexibility
-----------
Geronimo should meet anyone's needs from very lightweight to very
heavyweight.
Generally, the distribution option should be:
1) Minimal -- kernel and command-line/script administration tools only
2) Web -- web container and web admin tools
3) J2EE -- certified J2EE stack with web admin tools
4) Installer -- select from the above "canned" solutions and customize
The included tools must make it extremely easy to download and install
additional features (e.g. plugins) to add on to the basic
distribution. And,
of course, anyone is free to create more comprehensive
distributions by
bundling plugins and distributing the resulting package.
and changing the directory layout.
It should be possible to get an app running and then have "1-click"
options
to strip down the server to only what that application requires.
It should
also be possible to easily replicate a Geronimo installation to
another
machine (or to another existing Geronimo installation). It should
also be
possible to export an environment to run a J2EE application client in
(ideally, export it as a dynamic Java Web Start configuration so
you can just
run it on your local PC by clicking a link in the console).
This feature should be available via a utility, so a user can easily
add a "download a think-client" button to their web application. I'd
also add "create an applet" and "create an installer" options.
Performance & Scalability
-------------------------
Performance must be comparable to other application servers in key
areas.
Geronimo should support clustering of web and EJB components for
scalability
and fail-over fault tolerance. Geronimo should work with common
hardware
load-balancers.
Benchmarks should be made available with clear instructions for
users to
configure and run them on Geronimo as well as on other application
servers.
There should be clear performance tuning guidelines, and the
performance
tuning options should be extremely accessible (e.g. provide a
dashboard-
style page with all the settings to tune a web application in one
place
along with recommendations for the various settings).
Benchmarks we create should reflect real world applications.
Application Portability
-----------------------
It should be as easy as possible to port applications to Geronimo,
meaning:
"to and from Geronimo"
- reduce the need for Geronimo-specific XML configuration files
- simplify and minimize required settings in Geronimo-specific XML
configuration files (e.g. eliminate nested namespaces, provide
optimized
file formats for common things like database pools, eliminate
target names
in references)
- Isolate the application classpath from Server internals (Spring,
logging)
- Make common but non-standard code work (global JNDI lookups, etc.)
- Support file layouts, config files, scripts, termininology from
other
popular application servers (or stay as similar as possible)
- Provide conversion tools to import configurations from other app
servers
It should be clear when you are using a geronimo specific feature to
avoid a surprise later.
Some popular J2EE applications should be ported to Geronimo to
confirm that
the process is as painless as possible.
Geronimo should run on as a many platforms as possible.
Administration & Management
---------------------------
Geronimo should provide command-line, Ant, Maven, and web versions
of all
key tools. This includes tools to:
- get a list of available plugins
- download and install plugins
- deploy/redeploy applications
- start and stop the server
- export an application client wrapped in Java Web Start, even
including
auto-generated SSL keys/certs for mutual authentication.
The web console should be at least as function as the BEA WebLogic web
console. It should make it easy to both configure the server and
gather
runtime statistics. It should make it easy to run a second
Geronimo instance
on the same machine (using different network ports). It should be
possible
to rearrange the console content to suit the user's needs/style, or
at least
provide breadcrumb-type access to frequently used functions.
It should be possible to set up several Geronimo configurations
that share
the same core installation files but have their own configuration
files,
deployments, etc. similar to WebLogic domains (but not like JBoss
which
copies too many JARs into each configuration).
Geronimo should include a Windows Service to run the server.
Ideally, it
would also have a service like BEA Node Manager to start and stop
servers
on remote machines.
Geronimo should include scripts or command-line tools that make it
easy to
perform and/or automate common tasks such as deploying a new
database pool or
adding a new JMS destination.
Geronimo should provide packaged integration for management tools
such as MC4J
and JConsole. It should be easy to construct custom management
tools using
Geronimo maangement APIs.
Individual plugins should be able to include management plugins
that fit into
both the console and the command-line tools. The user should be
able to
update the layout and navigation to customize their own experience.
Development Tools
-----------------
In additional the aforementioned tools, Geronimo should provide
detailed
integration with popular IDEs including Eclipse, IntelliJ, and
NetBeans. The
integration should include starting and stopping the server,
debugging, and
generating Geronimo deployment plans for application modules.
Geronimo should also include comprehensive XDoclet support.
Geronimo should provide tools to streamline development wherever
possible,
including things like (note Rails influence):
- generating persistence classes and simple web screens on top of
them
- populating a database with test data
- rolling back to a previous version of an application
Developer Experience
--------------------
Geronimo should produce high-quality error message. Every
deployment should
be validated according to the relevent specification's rules before
Geronimo
attempts to configure and run it. The deploy tool should always
display
relevant errors to the user (without additional arguments).
It would be great to create a more robust error-handling system
with codes
for internationalized messages, linked to a Wiki with discussion
and reports
from the field on when each error was encountered, how to work
around it,
links to related Jira issues & patches, etc.
It should be possible to easily enable performance traces that
break down the
time spent in each user-provided method (or important Geronimo
function such as
a persistence operation or JTA commit) over the course of a single
call/transaction. It's OK if this introduces overhead, so long as
it produces
usable aggregate information (62% of each call to /myapp/hello
spent "here").
Documentation
-------------
Geronimo should include comprehensive free documentation, including:
- Reference for server and application configuration, emphasizing why
particular settings are important, when you should use them, and
how you
decide what to set them to
- Howto's for writing your first J2EE applications with Geronimo
- Howto's for advanced server / administration tasks
- Detailed guides for available plugins
Production Integration
----------------------
Geronimo should provide canned integration with popular open source
and
commercial products in categories such as:
- Databases
- Distributed caching
- LDAP, single sign-on, & identity management
- Portals
- SOAP/XML stacks
- ESB/JBI/integration tools
- Scheduling
- Reporting
- Web frameworks
- Debugging/optimization tools
- Performance testing
- ISP virtual hosting / control panels
- Applications (samples, business apps, bug trackers, CI, etc.)
In many cases this will include an actual Geronimo plugin, but for
some areas
it may only include documentation (how to configure the tool and
Geronimo to
work together) or code and documentation (if the integration
requires extensive
customization so a plugin isn't flexible enough). In any case, the
package for
each product should include comprehensive documentation.
Updates and Upgrades
--------------------
Geronimo should include a strategy for updating a server in-place
to the latest
maintenance release, or at least to apply critical fixes. Ideally,
this will
not break any existing plugins or applications.
For major new versions of Geronimo, there should be an upgrade tool
to convert
configuration files, in any cases where Geronimo will not accept
configuration
files built for the previous version.
I think we should explicitly state we will never support unreleased
versions (i.e., no upgrade support from unstable builds).
Just Works
----------
Geronimo is arguable the last to the J2EE table and there is a lot of
built up knowledge in our users. We should leverage that knowledge
as much as possible. There should be no-surprises and no-docs
required. In places where we deviate from the defacto standard, we
should try to make the break obvious and explicit. The worst are
subtle differences and they should be avoided.
-dain
