Re: [ebxmlms-develop] Variable interpolation in configuration

SourceForge Headquarters 1320 Columbia Street Suite 310 San Diego, CA 92101 +1 (858) 422-6466

On Fri, 2003-02-07 at 05:01, Patrick Yee wrote:
> Dear Jason,
> OK, we have added your patch to the source tree. Thanks for your effort.

Amazing thank you!

I will strip down the little application server that we have to only
contain Hermes and put it up as an example of how easy it can be to
install Hermes. It consists of all OSS pieces so anyone could use it as
they wish. Our little application server, call Plexus, also uses JMX so
I will probably try to whip up a little MBean so that Hermes can be
managed with a JMX console.

Much appreciated, thank you very much for listening. You guys are great!
:-)

> Regards, -Patrick
> 
> ----- Original Message -----
> From: "Jason van Zyl" <ja...@ze...>
> To: <ebx...@li...>
> Sent: Tuesday, February 04, 2003 4:28 PM
> Subject: Re: [ebxmlms-develop] Variable interpolation in configuration
> 
> 
> > On Tue, 2003-02-04 at 03:02, Patrick Yee wrote:
> > > Hi Jason,
> > >
> > > Thanks for the suggestion. However, after some discussion, we think the
> > > change is not quite necessary because:
> > >
> > > 1. Hermes deployment is not a day-to-day work. We expect the
> configuration
> > > will not be changed frequently. So using static values will be adequate
> for
> > > most of the time.
> >
> > I have integrated Hermes into our application server which might be
> > installed anywhere in the filesystem on machines with various operating
> > systems. I need to be able to dynamically configure Hermes because I
> > don't know where the installation is going to land. Something like
> > "/tmp/hermes" might possibly work on unix machines but it certainly
> > wouldn't work on other platforms. In addition, we like to keep all the
> > files for our application grouped together. We don't care where they are
> > grouped together. Without interpolation I can't provide the type of
> > installation that we require. I do not know ahead of time where our
> > clients will install our product.
> >
> > > 2. In the scenario that you suggest, we are only transferring the
> > > "hard-wiring" of property values from Hermes's configuraiton file to the
> > > application server's configuration files.
> >
> > We don't hardwire anything. Everything is dynamic. Our application
> > server works from the directory where it is installed. We don't know
> > where ahead of time but when our container starts up it gathers
> > information from the environment and makes that available to all our
> > components running in the container.
> >
> > > There is anyway a file which
> > > should "hard-wire" the property values, which is not portable from file
> > > system to file system. Under this basis, we believe to "hard-wire" the
> value
> > > in Hermes property file is acceptable.
> >
> > You can't make an installer with Hermes in it without variable
> > interpolation or some sort of runtime configurability. Variable
> > interpolation is a very simple solution to the general problem of
> > relocatable applications.
> >
> > > 3. We need some extra exception handling when trying to interpolating a
> > > non-existing system property. In this angle, this makes the
> configuration
> > > more complicated. Our design philosophy is to keep every behaviour
> > > deterministic. Of course, we may not be doing very well, but at least
> that
> > > is our direction.
> >
> > I can add any exception handling if I missed something, more than happy
> > to make things as robust as possible.
> >
> > Allow a form of runtime configurability has no down side and is of great
> > value to users trying to integrate Hermes into various products. It
> > allows Hermes to be used in unforseen circumstances. For example the way
> > I have Hermes working now inside our container it could be stopped,
> > package up because it's all in a single directory, moved to another
> > machine in a completely different path, started up and Hermes would work
> > just as it did. This might need to be done because of hardware failure
> > or just because someone wants to move it. Providing this kind of
> > flexibility, I believe, is well worth any extra work that needs to be
> > done internally in Hermes. And I volunteer to do the work :-) For me
> > this feature is essential for the operation of our container and
> > necessary to satisfy our user requirements.
> >
> > > What do you think? Let's discuss about this. Thank you for your
> continuous
> > > input.
> >
> > Happy to help, you've saved me months of development time so I'll
> > contribute however I can.
> >
> > > Regards, -Patrick
> > >
> > > ----- Original Message -----
> > > From: "Jason van Zyl" <ja...@ze...>
> > > To: <ebx...@li...>
> > > Sent: Sunday, February 02, 2003 12:45 AM
> > > Subject: [ebxmlms-develop] Variable interpolation in configuration
> > >
> > >
> > > > Hi,
> > > >
> > > > I've added variable interpolation in the XMLProperty.java file so that
> I
> > > > can more easily integrate Hermes into our application server. The
> > > > interpolation only works with system properties with the "ebxmlms"
> > > > prefix.
> > > >
> > > > So I'm setting a system property in our application server with:
> > > >
> > > >   <system-properties>
> > > >     <property name="ebxmlms.basedir" value="${plexus.work}/ebxmlms"/>
> > > >   </system-properties>
> > > >
> > > > And then I can do something like the following in the
> > > > msh.properties.xml:
> > > >
> > > > <?xml version="1.0" encoding="UTF-8"?>
> > > > <Property>
> > > >   <MSH>
> > > >     <Log>
> > > >       <!-- "JDK" or "LOG4J" -->
> > > >       <UseLogger>LOG4J</UseLogger>
> > > >       <!-- empty path: user.home -->
> > > >       <LogPath>${ebxmlms.basedir}</LogPath>
> > > >       <LogFile>msh.log</LogFile>
> > > >       ...
> > > >     </Log>
> > > >   </MSH>
> > > > </Property>
> > > >
> > > > This makes it very easy for integrators, like myself, to move the
> > > > application server around the filesystem and have things completely
> > > > self-contained.
> > > >
> > > > So this means we can deploy Hermes and not have to deal with absolute
> > > > paths which is essential for our installation setup.
> > > >
> > > > You can find the file here:
> > > >
> > > > http://www.apache.org/~jvanzyl/ebxmlms/XMLProperty.java
> > > >
> > > > I'll send changes in whatever form you like. Do you prefer patches or
> > > > whole files?
> > > >
> > > >
> > > > --
> > > > jvz.
> > > >
> > > > Jason van Zyl
> > > > ja...@ze...
> > > > http://tambora.zenplex.org
> > > >
> > > > In short, man creates for himself a new religion of a rational
> > > > and technical order to justify his work and to be justified in it.
> > > >
> > > >   -- Jacques Ellul, The Technological Society
> > > >
> > > >
> > > >
> > > > -------------------------------------------------------
> > > > This SF.NET email is sponsored by:
> > > > SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
> > > > http://www.vasoftware.com
> > > > _______________________________________________
> > > > ebxmlms-develop mailing list
> > > > ebx...@li...
> > > > https://lists.sourceforge.net/lists/listinfo/ebxmlms-develop
> > > >
> > >
> > >
> > >
> > > -------------------------------------------------------
> > > This SF.NET email is sponsored by:
> > > SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
> > > http://www.vasoftware.com
> > > _______________________________________________
> > > ebxmlms-develop mailing list
> > > ebx...@li...
> > > https://lists.sourceforge.net/lists/listinfo/ebxmlms-develop
> > --
> > jvz.
> >
> > Jason van Zyl
> > ja...@ze...
> > http://tambora.zenplex.org
> >
> > In short, man creates for himself a new religion of a rational
> > and technical order to justify his work and to be justified in it.
> >
> >   -- Jacques Ellul, The Technological Society
> >
> >
> >
> > -------------------------------------------------------
> > This SF.NET email is sponsored by:
> > SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
> > http://www.vasoftware.com
> > _______________________________________________
> > ebxmlms-develop mailing list
> > ebx...@li...
> > https://lists.sourceforge.net/lists/listinfo/ebxmlms-develop
> >
> 
> 
> 
> -------------------------------------------------------
> This SF.NET email is sponsored by:
> SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
> http://www.vasoftware.com
> _______________________________________________
> ebxmlms-develop mailing list
> ebx...@li...
> https://lists.sourceforge.net/lists/listinfo/ebxmlms-develop
-- 
jvz.

Jason van Zyl
ja...@ze...
http://tambora.zenplex.org

In short, man creates for himself a new religion of a rational
and technical order to justify his work and to be justified in it.

  -- Jacques Ellul, The Technological Society