30 December 2008

Teaching Servlets and JSP

It's the end of a week teaching Sun's SL-314 course -- "Web Component Development with Servlets and JSP" in Cape Town. It's been challenging and demanding, but, above all, fun! I had a great bunch of participants on the course, a couple of whom were old friends from an "Intro to Java" course (Sun's SL-275 course) some months ago.

The course materials are pretty good, although with a couple of misfeatures -- in my ever-so-humble opinion, as always -- and one glaring omission! (Never mind the details; I won't bite the hand that feeds me. This time. Rest assured that I've passed my thoughts on to the good people at Sun Education.) However, the whole sequencing and structure of the course has set me thinking, "How would I go about structuring such a course? What examples and challenges would I use for lab work?"

I take this teaching stuff pretty seriously1. So I'm always looking for ways to add value above and beyond what is offered by the course materials. Of course, the most valuable thing a trainer can bring into these sorts of skills-oriented technical courses is one's own experience actually using the technology on real-world projects. But beyond that, a lot of value can be added (or subtracted) by the sequence, timing and manner in which the material is presented. In a 5-day course time is terribly limited, so practical examples and labwork are necessarily very constrained, so it is very hard to work-up really good examples.

Setting examples and lab-work for courses is actually a very hard problem. You don't want to restrict the work to toy problems -- students pick up on that very quickly, and, even more quickly, lose interest in the course material, and, more importantly and with longer-term consequences for the remainder of the course, they lose respect for the course (and sometimes for the instructor, too.) On the other hand, time is very limited -- perhaps a couple of hours for any given issue, so extensive examples take too long to implement.

Then, too, one is in the position of trying to illustrate and/or reinforce key points in the course material, and developing actual code always involves a measure of extraneous detail -- housekeeping code. It adds nothing to the teaching purpose of the exercise, but it certainly chews into the time available!

And -- not to be neglected -- I think it is important that examples be at least a little bit entertaining. After all, we can do order-entry at work anytime... But there's a borderline across which "entertaining" becomes "irrelevant". (Much the same can be said of micro-benchmarks.)

Relevance? You wanted relevance from a blog post? As opposed to rambling?

OK.

I'm starting to put together my own material for a number of courses, centring around the gaps in the corporate professional training space (OO and Java technical matters, of course.) that I've been seeing over the past decade.

(Of course, now is a brilliant time to be putting my own course-material together. In times of economic downturn, the very first thing to get the axe is training! How short-sighted is that?)


[1] As with most things, the more you put into it, the more you get out of it!

15 November 2008

Brain Delayed - In Transit

On my way down to Cape Town -- yet again -- for a Java Intro course -- yet again...

On arrival at the checking-desk, get told that I'm not booked to go to Cape Town, but am eventually found to be on my way to George from Cape Town. Returning to Cape Town on Friday. Wow! What happened here? OK, so off to the booking office where I have to fork out an extra R700 to cover the ticket change. Fortunately the SAA staff at George and I know each other by first name. (As a result I seldom have to produce ID to check in -- most of the staff can ID me by sight. Beat that for personal service! ;-)

Sudden thought: Let's check the car rental reservation. Sure enough! I'm booked to pick up a car in George. Get that one changed. Things are so screwed up at this point that I called the B&B where I'm allegedly booked to stay in CT. Yes, indeed, they DO have a reservation for me.

WTF was somebody at the travel agency thinking? This guy is going to fly from Cape Town to George, pick up a car there, and then stay 5 nights in Cape Town before reversing the journey?

Now I only have to waste an extra hour-and-a-half in the airport. I just love hanging about in airports, don't you?

25 September 2008

Back in the Saddle: Java 101

Interesting to be back in the Training Game. It is a Java 101 (Introduction to Java Programming for Programmers) course. With some differences.

Its all for one corporate client. My God, its been a long time since I had to deal with Corporate IT Thinking. There's some of it that exists for good reason. And then there's a whole lot of crap. Stuff that's more to do with politics, staking out of turf, ass-covering... The real downside for a Java 101 course is not so huge, but still... everybody is from the same organisation, though they might well be from different planets, considering the departments they're drawn from... But, there's still not a lot of cross-pollination of ideas. The whiff of groupthink.

I've taken the format of the "usual" 5-day course and adapted it somewhat to a 6-day format split over two 3-day sessions a couple of weeks apart, so there's a lot more breathing room, but, for any "Intro to X" course there is a certain body of knowledge that has to be covered, and there's a certain Logic to the order in which material has to be presented, so there's no escaping... There's just a bunch of stuff that has to get taught before people can realistically handle a tutorial (a.k.a. "homework".) All resulting in a pretty heavy First Three Days. I've just finished Day 3 ("Subscriber Trunk Dialing".) I'm exhausted.

Differences: In the usual "5-day" format I'd have to be really winding up my energy to stay the pace for Day 4. This time around I get a week-long break, and get to start fresh. Mmmmm... Gooooood!

Happily I have a fairly bright bunch. Quite a mix of backgrounds, all the way from a university graduates to "just-a-programmer-can-I-google-a-solution-and-cut-n-paste-the-code". The usual chirpy heckler who borders, at times, on irritating, but helps keep things alive. The usual "deeply tech" who catches all my mistakes and omissions, and keeps me on my toes.

I'll confess that I'm having a ball!

11 September 2008

Infrastructure Fix

Finally!  Took a day off from preparing for the (Advanced Architecture and Design) course I'm hosting next week, and spent the time getting my local infrastructure back on its feet after a breakdown some weeks ago.  Basically the LAN server died... motherboard or CPU. Suddenly we realised just how much we've come to depend on that little machine!  DNS caching, plus names for all the machine on our farm-LAN1, HTTP proxy, local Subversion server, file-share, music streaming, and not to mention supplying the base-infrastructure for some Jini services that come and go as we play around with Jini and JavaSpaces.

So now that we've beefed-up the CPU and disk a bit, it was "just" a case of getting all the bits of server software installed and cleanly configured. Nothing difficult, but it all takes time! Especially when you're a bit.... fastidious?... about getting the config "right", as opposed to "just poking things until they work". I truly despise "voodoo config" where people don't really make the effort to understand the impact and effects of what they're doing, and fuck it up royally as a result.  "Oh, well, I'll install mod_disk_cache and mod_mem_cache... after all, two caches must be better than one, mustn't they?"  Ding!  You Do Not Win The Lounge Suite!

Well, its been fun! And finally I can forget all about it again until the next hardware failure. The only thing I really would like to achieve is to get the server quiet2, and get its power-consumption way, way down!  And maybe have a few more tiny-little servers...

[1] The term "server farm" takes on a whole new significance ;-)


[2] Yeah, I'm a complete arsehole about noise. I really, really, really hate noise...

22 August 2008

Courseware: The Next Step

Just received my Instructor's Manual (only a week late!) for Sun's SL-425 "Architecting and Designing J2EE Applications"1 and I'm very happy to see that it is basically the same course as the old "Architecture and Design" course I taught several times lo' those many years ago when I was so frequently on my feet as "Herr Instructor".

This is easily the best2 course I ever "taught"! It is aimed a senior, experienced designers and developers3, and confronts head-on the sticky few-good-answers stuff, the ill-defined and the fuzzy grey areas. I have always run the course in a round-table "workshop" format. When you get 8 or 10 senior developers into a room, each with a decade or two of experience, you're not going to be their Teacher. And you sure as hell better not have a tender ego. "I don't know" is a frequent answer. The job is much more one of facilitation: Keeping discussion on-track, drawing quieter participants into the discussion, acknowledging expertise and encouraging people to share their (often vast!) experience. I found it hugely enjoyable to engage with seriously expert people, and to facilitate drawing out their expertise. And I learned a lot!

It has been a very long time that I have wanted to run this course again, so I'm looking forward to it hugely!

So: I have a couple of weeks to catch-up on the changes since last it taught facilitated this course. Mainly the technology has caught up with the tech: Where there was only CORBA or RMI a decade ago, there are now a host of J2EE technologies, and the course now includes them. Where a decade ago the whole idea of enterprise-architecture patterns was pretty new and unheard-of, now there's the J2EE Blueprints Catalogue (even if those yanks can't spell "Catalogue"!)

Of course I'll probably be unable to resist the temptation fo slipping in a few sly teasers about Jini and Javaspaces -- but Hey! Sun seem to encourage instructors to go beyond the boundaries of the course material, and encourage us to bring our own experience into the classroom. Or workshop in this case.

I am still thinking about floating my own version of this course, perhaps a little less attached to Java tech, so that more people might engage. The absolutely best runs of the course were when we had many people from different organisations and backgrounds. Cross-pollination really works. Ask plants!
----
[1] Is there such a word as "Architecting"? My spelling-chequer doesn't seam to think sew.


[2] "Best" from my point of view, anyway. Though, I can honestly report that every participant I've ever had on this course reported exactly the same sentiment!


[3] I don't believe the term/job-title "Architect" had any currency back then. Whilst it had certainly been invented4 it was certainly not popular. In fact there still was no such Job Title as "Software Designer" back then. My boss had to invent it for me!


[4] I believe that I was one of the (probably many) inventors of "Software Architect"a s a job title. Certainly not unique in that, though! Back in 1989 a technical career-path looked much like "Junior Programmer - Programmer - SeniorProgramer - Junior Systems Analyst - Systems Analyst - Senior Systems Analyst - Business Analyst..." I rejected the whole deal5 stating "Analysis is The Art of Taking Things Apart. I don't want to do that. I want to put things together, and that's called Design (and, at the high-end, Architecture)."


[5] ... in a bi-annual merit-assessment that became (in)famous as the one where I told my Manager, "If you want loyalty, get a dog! This is a business relationship; didn't you understand that?" Needless to say I got no increase that year. ;-)

19 July 2008

Datapro/Vox Spam Wrapup

Its been a long, long time... way too long... since I promised to report back on my complaint to the ISPA in which I accused Datapro/Vox Telecom of being spammers.

The first part of the ISPA's complaint-handling procedure is to have the parties try and resolve matters between them. Datapro's attempt to brush me off was a laugh:

So eventually, somewhere around March, the event wound its way to the ISPA's Complaints Committee who deliberated, and some weeks later, sent me a formal Ruling:

Datapro/Vox Telecom were found guilty of spamming, and fined R100 000 (about EUR10 000 at the time.)

Naturally Datapro appealed this decision, as was their right. Unfortunately the appeals process is quite a slow one, so it was only about 9 June that I was informed of the outcome of the appeals process:

On appeal it was found that Datapro/Vox Telecom were confirmed as being guilty of spamming (through address repurposing.) The fines were, however, reduced to R45 000, most of which has been suspended for 12 months, provided that Datapro/Vox do not spam again within that period of time. Effectively Datapro/Vox have had to pay a paltry R7 500 in fines. Their guilt remains undisputed.

This strikes me as the ISPA having no balls.

The Appeals Committee recomended that Datapro/Vox
...ensure that a working opt-out facility is provided on all marketing emails and to report back to the ISPA complaints administrator within 1 (one) calendar month of receipt of this report on remedial action taken by it. The Appeals Panel recommended (which recommendation is not binding) that such remedial action should also include cleaning its email marketing lists to avoid a repetition of this complaint. This could be achieved by way of a reminder email requesting recipients to confirm their desire to continue receiving such emails (opt in), which is preferable, or by requesting them to indicate their preference not to receive such communications (opt out), which is adequate and then abiding by the indicated preference.
To my knowledge none of this has happened. I have received neither an opt-in request, nor any opportunity to op-out.

The only communication I have had was on 3 June -- 8 days after the Appeal Ruling -- I received yet another marketing spam from Datapro/Vox... still no opt-out link, still no confirmed opt-in. I just have not had the time or energy to follow-up with another complaint of this violation of the suspension conditions imposed by the ISPA on Datapro/Vox.

Further, the ISPA's documentation carries a notice stating
PRIVATE AND CONFIDENTIAL:
All communication is confidential and may not be distributed.
See http://www.ispa.org.za/commsrules for more info.
so I am effectively barred from making the original PDFs available, despite (or perhaps because of) my having made it clear to the ISPA that it was my firm intention to publish the course of events and all documents.

I am also unable to find any notice, link or reference to this ruling on the ISPA website. Are they too afraid of the potential income-loss should one of their largest spammers members get pissed-off enough to depart the Association?

A pretty sorry indication of the general state of the local ISP industry, I'm afraid.

03 July 2008

Power to the Purple

A week of power-supply problems. Not Eskom's fault, this time, but more localised failures.

First the power-supply for the network server had a fan stop turning. I could have taken the chance on the unit working without cooling, since it is relatively lightly loaded -- no graphics cards, only a single disk -- but, since I had a spare power-supply unit handy it was a task of mere minutes to swap the faulty unit out and get the server back into action. It is a fairly key piece of our little home network, being a web-cache, local domain-name server and cache, Subversion repository and file-share space, so we miss it badly when it is down.

Then the power supply on my desktop machine decided to follow suit. Also a fan failure. I hate those crappy little fans! There's absolutely nothing wrong with the basic electronics of the power supply itself, but the ball bearings in the fan have died. Pricing for a new power-supply runs from a little over R100 if I were in Cape Town with easy access to wholesalers, through R200 from a web-shop, all the way to R300 from the local PC shops! This is for the most basic 350W PSU -- none of that fancy gaming-machine stuff for me. (Though I will confess to being tempted by a unit costing around R800, simply because it is alleged to be completely quiet! I'm a self-confessed anti-noise-maniac.)

My guess is I'm going to spend an hour messing about with the soldering iron, installing new fans (I have a couple just lying about) in the "faulty" power-supplies.

At the same time, several warnings from my server-supplier in London telling the story of a week-long tail-of-woe about power-supply into the datacentre. Apparently a failover switch failed to work correctly during a power-outage last Sunday, causing the battery-based UPS to take the entire load for about 10 minutes before the batteries were totally drained. All servers in the DC went down hard. It has taken them until Thursday to isolate the problem and replace the parts (electrical and mechanical) that were at fault.

During the whole affair, all server owners have been kept fully informed via RSS feeds and emails at every step of the way, since there is a risk (however slight) that servers might go down if there is a power-grid outage again and the on-site staff -- now fully briefed on managing a manual switch from grid power to the backup generator -- should get taken-up at just the wrong moment.

This is exactly the sort of thing I expect from server providers and datacentre operators. Everybody understand that, despite the best-laid plans, sometimes shit happens. It is how they respond, and how transparent and communicative they are in responding to the crisis that truly matters.

This is in very sharp contrast to Verizon's datacentre in Durban, where my other client's servers are housed. About 10 days ago they had some electrical work going on in the DC, which in turn made some server-moves necessary. They did all this without warning their clients that there might be some risk to their operations. Needless to say, my client's servers went down without warning in the wee hours of Sunday morning. No heartbeat monitoring in place, so it was Monday before anybody knew that something was wrong. No peep from Verizon to their customers. Half-arsed, I call it.

There's a lesson in all this about Single Points of Failure. I've been warning for over 8 months that having all the servers housed in a single DC, or even in a single city, is a risk. Maybe now the business will take some action, but, given the general lack of respect or attention to the fact that, like it or not, they are a technology business, I have my doubts.
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