Sep

29

A More Usable Usability

Filed Under Blackboard Vista, Interweb, University | 3 Comments

Previously I have seen usability describing ease of using a web site. These four essences of usability are interesting.

I believe that to satisfy customers, a Web site must fulfill four distinct needs:

  • Availability: A site that’s unreachable, for any reason, is useless.
  • Responsiveness: Having reached the site, pages that download slowly are likely to drive customers to try an alternate site.
  • Clarity: If the site is sufficiently responsive to keep the customer’s attention, other design qualities come into play. It must be simple and natural to use – easy to learn, predictable, and consistent.
  • Utility: Last comes utility — does the site actually deliver the information or service the customer was looking for in the first place?

— Web Usability: A Simple Framework

The first two items deal with system administration issues like the network, server(s), database, or application. Redundancy and proactive dealing with problems before they impact the system hopefully maximizes availibility. Optimization for performance hopefully maximizes responsiveness. An unhealthy database could fail to deliver information.

The last two items deal with design issues. More utility issues are likely based in design than tuning.

UPDATE: In my past life as a “Webmaster,” my fingers were dirty in all four aspects of usability. These were my servers and while not my design, I certainly influenced it by cleaning up the HTML and presentation. We created in-house everything except some outsourced photography and the Apache web server.

Blackboard’s Vista is a proprietary application with decent opportunities for instructional designers to provide clarity and utility. As much as it provides, clients often purchase or create additional applications to integrate with Vista to fill in holes Blackboard left. Okay, technically, WebCT left those holes, but Blackboard took the same model with Academic Suite. Blackboard doesn’t really intend to fill in those holes. They should for issues affecting most of their customers on each platform. This is the same approach taken by open source products with the caveat that third party companies are not filling in the holes, customers are developing their own solutions and providing back to the community.

The declining responsiveness of Vista over time definitely seems to create one frustrating difficulty for some clients. As the database tables get larger, responsiveness of the sites declines. Ouch. Delete it all… Oh, wait… Can we really do that?

Sep

28

links for 2007-09-28

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Sep

27

links for 2007-09-27

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Sep

25

VM(Night)Mare

Filed Under Computers | 1 Comment

So, I need to install software on a couple servers which don’t exist. They are virtual: VMWare ESX. I can see and login to the web site. However, its frustrating to consistently get a working console. I get a partial page with “Error on page.” Going to the error reveals:

Browser#ResponseReceived(): invalid content type text/html (status 200) while processing vmNavigatorXml.do

What I have tried so far.

  1. Firefox 2.x is unsupported. I tried it; it didn’t work.
  2. So I tried IE6. That worked fine. Over a week later it doesn’t. Oh…kay…
  3. Figured iehttpheaders could have been the culprit. It was the last thing changed, so I removed it. Didn’t help.
  4. I tried Firefox 2.x again. No good.
  5. I tried Netscape 7.2. No good.
  6. Called workstation support, works for him, I removed IE6 and added it back. It worked! For a day.
  7. So I removed IE6 again and put it back. It didn’t help.
  8. Checked McAfee Buffer Overflow Protection. Still disabled.
  9. So I installed IE7. Still doesn’t completely load the page.
  10. So, I tried PortableApps Firefox 1.0.8 (which is on the supported list). No dice.
  11. I noticed I have multiple version of Java, I removed all but the next to latest, Java 1.6.0. No good.
  12. I removed all the versions of Java. No help.
  13. Figured out there is a VMWare plugin.
  14. Disabled the plugin in IE7. Nothing.
  15. Found where the plugin is installed. Uninstalled it. Now when I visit, I don’t get a request to install it.
  16. So I don’t have the plugin. Nor can I install it.

For you Apple Switchers who read this. Macs are not on the supported list. Though, Linux is!

I’ve wasted most of two afternoons on this.

Sep

24

Cell Phone Madness

Filed Under Corporations | Leave a Comment

In case you haven’t noticed, I have have a new cell phone. Give me a call if you have my phone number. Actually, if you can find the number, then I’d even more love for you to call. :) If only to congratulate your mad skillz.

Back in December I read online Amazon had fantastic deals on cell phones with purchase of a plan. So I looked. It occurred to me I ought to be at the end of my 2 year agreement. I checked and sure enough I was. However, did I really want a new phone? What features did I want? Maybe I should switch carriers? The iPhone announcement surely didn’t help.

There wasn’t a straw. There wasn’t a deal. It just dawned on me that if I didn’t take the plunge right at that moment, then I probably would still be using the same old phone until I broke it. Maybe I’d even be that guy carrying a phone from 1985. in 15 years (assuming I didn’t break it). I did realize one of my apprehensions was visiting a store. So I looked online a couple times, dithered, and finally, I went with the Samsung SYNC.

New phone, new manufacturer, new menus, new features, new cables, new problems.

Problem 1: I made the move. AT&T’s web site didn’t say what would come in the box. Probably I could have found this out with some research. At the worst, I could have gone to the store. The whole point was to avoid the store. So, I ended up ordering accessories about an hour after getting the phone out of the box. Two of the three arrive today.

Problem 2: Profile timers are “teh win”. I am lazy. A feature I enjoyed of the candybar was the profiles could be set to expire at a specific time. So every morning I could set it to silent and expire after the end of the work day or after a movie.

Problem 3: Put MicroSD card in slot, try to format card, see “Error”. No, really. Just “Error”. What does THAT mean? I thought maybe the capacity of the card was more than the phone could accept. So, I looked on the web. Eventually, I did find that my card is of the right size and made by the right company, so it should work. Then I read that one of the cons of the phone is the springs have difficulty ejecting the card. Maybe they also had trouble in seating it? So I tried reseating it a couple times, eventually choosing to use a point object to push it more than in the slot. Bingo!

All that said, I am more than happy with my new phone.

Awesomeness 1: It feels right in my hand. The buttons are not made for 10 year old kids.

Awesomeness 2: The convenience of a camera in my phone.

Awesomeness 3: The brick contributed to the potentially illegal sagging pants.

Sep

24

links for 2007-09-24

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Sep

23

Most Studies Are Wrong

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Science Journal - WSJ.com:

Statistically speaking, science suffers from an excess of significance. Overeager researchers often tinker too much with the statistical variables of their analysis to coax any meaningful insight from their data sets. “People are messing around with the data to find anything that seems significant, to show they have found something that is new and unusual,” Dr. Ioannidis said.

Back in my undergraduate days, I recall wondering if my experiments had found something significant, then my professors would not have been such hard asses. Most of my time in the library was seeking to find something original to impress. I got more props from my peers than my profs.

Sep

22

BbWorld Presentation Redux Part II - Monitoring

Filed Under Blackboard Vista, Conferences, Work | 1 Comment

Much of what I might write in these posts about Vista is knowledge accumulated from the efforts of my coworkers.

This is part two in a series of blog posts on our presentation at BbWorld ‘07, on the behalf of the Georgia VIEW project, Maintaining Large Vista Installations (2MB PPT).

Part one covered automation of Blackboard Vista 3 tasks. Next, let’s look at monitoring.

Several scripts we have written are in place to collect data. One of the special scripts connects to Weblogic on each node to capture data from several MBeans. Other scripts watch for problems with hardware, the operating system, database, and even login to Vista. Each server (node or database) has, I think, 30-40 monitors. A portion of items we monitor is in the presentation. Every level of our clusters are watched for issues. The data from these scripts are collected into two applications.

  1. Nagios sends us alerts when values from the monitoring scripts on specific criteria fall outside of our expectations. Green means good; yellow means warning; red means bad. Thankfully none in our group are colorblind. Nagios can also send email and pages for alerts. Finding the sweet spot where we get alerted for a problem but avoid false positives perhaps is the most difficult.
  2. An AJAX application two excellent members of our Systems group created called internallyl Stats creates graphs of the same monitored data. Nagios tells us a node failed a test. Stats tells us when the problem started, how long it lasted, and if others also displayed similar issues.We also can use stats to watch trends. For example, we know two peaks by watching WIO usage rise to a noonish peak slough by ~20% and peak again in the evening fairly consistently over weeks and months.

We also use AWStats to provide web server log summary data. Web server logs show activity of the users: where they go, how much, etc.

In summary, Nagios gives us a heads up there is a problem. Stats allows us to trend performance of nodes and databases. AWStats allows us to trend overall user activity.

Coradiant TrueSight was featured in the vendor area at BbWorld. This product looks promising for determining where users encounter issues. Blackboard is working with them, but I suspect its likely for Vista 4 and CE 6.

We have fantastic data. Unfortunately, interpreting the data proves more complex. Say the load on a server hosting a starts climbing, its the point we get pages and continues to climb. What does one do? Remove it from the cluster? Restart it? Restarting it will simply shift the work to another node in the cluster. Say the same happens with the database. Restarting the database will kick all the users out of Vista. Unfortunately, Blackboard does not provide a playbook on what to do with every support possibility. Also, if you ask three DBAs, then you will likely get three answers.
:D

Its important to balance the underreaction and overreaction. When things go wrong, people want us to fix the problem. Vista is capable of handling many faults and not handling very similar faults. The link example was a failed firewall upgrade. I took a similar tact with another firewall problem earlier this week. I ultimately had to restart the cluster that evening because it didn’t recover.

Part three will discuss the node types.

Sep

22

links for 2007-09-22

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Sep

20

links for 2007-09-20

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