[albatross-users] Welcome to Albatross-users

[Tim Churches]

Andrew McNamara wrote:
> 
> Since the list has been rather quiet, I thought I would just say "welcome"
> to the 3 non-Object Craft subscribers on the list!
> 
> I have some questions for you:
> 
>   - Are you using Albatross or just considering it?

Andrew, Ben and Dave already know about our use of Albatross, since we
have contracted them to assist us withing with the development of our
application, but I'll describe it briefly for the other two subscribers
and for the list archives.

We are building, or rather have built a prototype epidemiological
mortality analysis system. It allows the user to specify a range of
quite complex parameters, such as the cause of death (picked from an
Albatross tree display of International Classification of Diseases codes
in three groups [ICD-8, ICD-9 and ICD-10] - the ICD trees each have
between 6,000 and 9,000 nodes in them, but Albatross manages their
display and unfolding perfectly, using very little code - very
impressive), age of death, residence, year of death etc, and then lets
the user specify what they want in terms of particular graphs, tables
and other statistical analyses. The number crunching is handled partly
by a data analysis engine we have written in Python (with help from Dave
Cole of Object Craft - we hope to release this engine separately in the
next few months) and is partly handled by the R open source statistical
package (see http://www.r-project.org). Thus, a set of inter-related
analysis parameters are built up and modified (in any order) by the user
through a number of different screens, and Albatross transparently
handles the maintenance of this 'state' i.e. the set of parameters being
specified. There are facilities to store and recall sets of parameters
too. Finally the user clicks "Submit" and their analysis is performed
and teh results displayed, as graphs and tables. The whole thing works a
treat and I am now happily extending the user Albatross-mediated
interface without reference to Object Craft (except for the occasional
request for help).

>   - Do you have any suggestions regarding the module or it's documentation?

Looks like you have already implemented most of them for the 0.6
release.

One thing which almost every application requires is logging. Would it
be possible to add some hooks into Albatross so that a logging class is
called automatically at given points in teh processing?

Would it be possible to incorporate the nifty cgitb (CGI traceback)
module which is now standard in python 2.2 into Albatross 9it is
available for early versions of Python - see
http://www.python.org/doc/current/lib/module-cgitb.html)?

Related to the last two requests, a built-in means of logging exceptions
and/or emailing their occurence and/or details to nominated addresses
would be useful.

>   - Do you have any questions?
> 
> We expect to do a 0.06 release shortly, as well as announcing the mailing
> list more widely - this release contains:
> 
>   - many documentation improvements,
>   - a samples installer,
>   - MD5 signing of hidden field data (which required a new "secret"
>     parameter to app objects utilising the HiddenField mixin),
>   - tag parsing now accepts either single or double quotes in attributes,
>     as well as allowing the quotes to be escaped with backslash.
>   - a new file based session recorder to supplement the hidden field
>     and session server recorders,
>   - a wrapper around the session server to allow it to be easily used
>     as a daemon on unix platforms,
>   - more unit tests, unit tests now use the current albatross instance,
>     rather than the installed instance.

Sounds good. Will the file-based session server support "migration" of
user sessions from one server to another eg if there is a "farm" of Web
app servers each accessing a shared file-based session server, then a
round-robin DNS can be used to route each HTTP request to the next
server and that server will load the correct application state.
Possible?

Cheers,

Tim C