Category: Technology

Bar Camp, Code Camp

I met some of the Bar Camp guys:

http://barcamp.org/

at ETech last week:

http://conferences.oreillynet.com/etech/

and mentioned Code Camp to them:

http://blogs.msdn.com/trobbins/archive/2004/12/12/280181.aspx

These two non-conferences seem to have a lot in common, though one is vaguely MS-centric (it was briefly known as MSDN Code Camp) with the other isn’t. Brian Button is putting together a Code Camp here in St. Louis soon, it will be interesting to see how it works out.

http://www.agileprogrammer.com/oneagilecoder/archive/2006/01/22/11023.aspx

SQL Server Log Shipping Fragility

In a customer production system, we use MS SQL Server 2000 “log shipping” extensively to offload reporting DB load to secondary servers… a common use of the technology. This generally works very well, most of the time.
We’ve noticed, though, that it can be somewhat fragile, in that it is easy to inadventantly run a SQL operation (such as a large index update, schema change, etc.) that results in many, many pages shipped, and hence in large log backup files, and large “standby” files – all of which are processed surprisingly slowly by SQL Server. The result of this (the fragility) is that the log ship destination servers can then take many, many hours to return to an operatonal state.
It turns out that one cause of this is that log backup (and hence log shipping) apparently happens at the “page” level: if one bit on a page changes, all 8K of the page is shipped.

A second cause is that if a log backup happens during the middle of a large operation, it will ship the partially complete operation; the destination servers will then generate huge “standby” files (we’ve seen them over a gigabyte) in the restore process.
One path forward is to to move up to SQL Server 2005, which has numerous log shipping improvements. Imagine my dismay to find this today:

http://sqljunkies.com/WebLog/acalvett/archive/2006/03/12/18993.aspx

in which Andrew Calvett found that the log ship monitoring functionality is much worse in SQL Server 2005 than in SQL Server 2000.

As usual there is likely a third party tool to make this better. But since log shipping is such a powerful and flexible tool for scaling up SQL Server based applications, it is disappointing to see the monitoring get worse rather than better. Perhaps in SQL Server “2010”…

Sea change in Web vs. Desktop Development

In the late 1990s, I rushed in to web-app development with a million other developers, following the demand. At the time I accepted that it took more work to get a web app working than a desktop app, using the tools of the era.

But looking at Ruby / Rails and TurboGears:

http://www.turbogears.org/preview/docs/tutorials/eajaxtg/paper.html

It strikes me that it is now *less work and less code* to get the functionality shown here working in a web app w/AJAX, than it would be to get it working in a rich client with Swing or in a multi-tier application in Delphi. The idea above that desktop client apps are less work than web apps, is no longer true. We are now paying a penalty when we choose to create non-web-apps.

Switched to WordPress

After a few years of using a barely-maintained homegrown CMS / weblog engine, I’ve switched to WordPress 2.0. Through a few hours of tedious migration work, most of the old content has been preserved. Moreover, a set of Apache directives like this:

RedirectMatch story-275- http://kylecordes.com/2005/09/09/direct-swing/
RedirectMatch printable-275- http://kylecordes.com/2005/09/09/direct-swing/

makes all (or very nearly all) of the old URLs still work.

Direct Manipulation Java Swing GUI Talk

At the St. Louis Java User Group meeting on Sep. 8, 2005, I gave a talk on building “Direct Manipulation” user interfaces with Java Swing. Here are the slide and code from that talk. The slides are quite limited, as the talk was spent almost entirely in the code – this is the kind of talk I prefer to give, with a lot of technical depth crammed in to the time allotted. Unfortunately this makes it somewhat less useful for people who weren’t at the talk; I’ve thought of making a “screencast” of the presentation for that reason.

Source Code and Presentation: SwingTalk.zip

Update: The sample code that got the most attention was the “flying boxes” code in the swingtalk.ordering package; you can try it now via Web Start.

Update: I presented this code again at the St. Louis Code Camp on May 5, 2007. Alex Miller picked it up and revamped it to use the new Swing Application Framework stuff coming (most likely) in Java 7.