AustLit

What I've done

• Dates-as-topics which were still lurking in the thesaurus have been converted to real "dates" in the works referring to them and deleted from the thesaurus.

• Work list format changed to support viewing and emailing of all or selected works in HTML, plain text, new tagged text and XML formats.

• Started further changes to the work list format and search options to support selection of work sort order. So far, order by date x title and order by title are operational. Hope to implement "book first" and "on-line text available first" orders next week.

• Subset search result pages now show contributor logos.

• The definition of the "Australian Responses to Asia" (ARA) subset was changed to include many more thesaurus topics. This required a way of flagging ARA associated topics in the thesaurus, necessitating a new attribute on thesaurus topics and minor changes to the thesaurus maintenance suite. The new ARA topics have now been flagged and the subset is working as required.

• Misc minor changes to maintenence suite over the last few weeks have included a new work type and template for reference works, marked-up text in the source note and maxmimum field length restrictions now enforced in the user interface.

• One-off query to find works with alt titles at the expression level and multiple manifestations of that expression.

• The system was stable and available except for a few seconds on a few occassions when I restarted the web server to allow updated work list functions to become operational.

  The Java "Tomcat" process was using more memory this week than usual, but the problem was tracked down to the new mode we are in now of delivering lots of "access denied" pages. As has been previously identified, the XSLT (XML stylesheet) package we are using seems to have a memory leak which we worked around by clearing all stylesheet templates from memory periodically (based on system activity). With this new mode of activity, the algorithm which decided when to clear all stylesheets needed a tweak - it was modified from working on the number of works/agents displayed to a simple elapsed time method: now, all stylesheets are released every hour regardless of activity. This has fixed the increased memory consumption problem.

  Sun have released the Java Virtual Machine 1.4.0 as a "release candidate" for public testing. This usually means that the official release is imminent (maybe a month). We are looking forward to the new release for the fix to the JVM hanging problem we occassionally experience.

  Middle Age

  Remember when you last acquired a new bookshelf? If is had moveable shelves, a big 'design' issue for you was to optimize the spacing. Regardless, you probably thought for some time about how to arrange the books - alphabetically, thematically, Dewey..., and how to distribute the free space amongst the shelves in anticipation of acquisitions.

  As time when on, if there was any "update activity" on the bookshelve's contents, your initial design probably became less optimal:

  • not enough space for the books beginning with "R", or on topics associated with "Golf" or "Fishing"
  • the "tall" shelf now had never-opened coffee-table books mixed with the "Reference" section atlases...

  and eventually it became time to take everything out of the bookshelf and reorganize.

  Like this bookshelf, AustLit is reaching "middle age" - the flexibility of youth has been challenged by hundreds of (self-)compatibility constraints which resist change. I've been noticing this over the past few weeks when adding in the new tagged-format options and work sorting options. Nothing major, just slight resistance of the original design and existing code base to being flexed, stretched and punctured.

  As with bookshelves, there comes a time when you take everything out and start again. The AustLit system is a long way away from that time - the design is sound, and what has been happening so far has happened almost entirely within that design.

  The main impact of recent changes has been in the time they take to test. Now that AustLit is a production system with paying customers, changes have to be carefully tested to ensure that they don't break or interact with existing functions in unexpected ways. And as the number of functions increase, the possibility for unexpected interactions increases.

  Most changes to AustLit will continue to be simple due to the basic architecture - new attributes, new relationships present no "threat" to the basic design. But they do require more work to update the summary, detail, HTML and tagged-text stylesheet, and to add to the search screens (if applicable) and test that the searches involving them haven't thrown the Oracle query optimizer into an unexpected new mode!

Next Week

• Function to support mass extract of records/scope into XML formatted file.

• Investigate problems with IE6 and the AustLit maintenance suite.

• Design/implement "public view" processing.

• Continue with work sorting options.

• Program to help linking of full text images to works.

• Multiple creation events for a work as a mechanism for allowing date ranges to be associated with agents responsible for works, eg editors of a periodical.

• Refining NBD Holdings searches.

• Combining searches

Link of the week

• Criteria for optimal web design (designing for usability) - Michael L Bernard

  Simple and effective guidlelines for designing web sites. Includes a wonderfully simple study of where items should be located on pages based on asking people where they'd first look to find certain elements such as a search box.

• Web design patterns - Martijn van Welie

  The American architect Christopher Alexander set forth a philiosophy of architecture, from the smallest nook to the largest city, based on recognising and implementing patterns of construction/implementation/use.

  His work has been very influential in the world of software, with numerous books of patterns to help software designers recognise common problems and solutions. Martijn van Welie has started a collection of patterns for web pages.