June 2007

Monthly Archive

Oh the spam!

Posted by Yannis Lionis on 20 Jun 2007 | Tagged as: Software

We’re all aware of spam, both email and snail-mail spam. It’s been around for ages, and we’ve come to be used to it. We’ve found ways to deal with it. Spam filters for email (although they are not quite as good as to eradicate the problem). Snail-mail, irritating as it is, has it’s positive point (about a quarter of all mail in the UK is spam, which means that if it wasn’t there we would all be paying more for postage). We’ve also come to know sms and telephone spam as well now, which is even more intrusive and harder to deal with. But ever since I started this blog I found out about blog-comment spam.

It’s scary how many spam comments I’ve gotten on this blog. They’re usually something that starts with “Nice site” and then goes on to list loads of links for cheap flights, cheap computers, cheap everything (as well as some more dodgy stuff). I never would have thought that a blog that’s been around for only about a couple of months would get bombarded daily with so much spam.

The moderation filter has of course been invaluable. The particular feature of WordPress to hold for moderation any comment with a link in it has done most of the work. Still, I get an email for every comment posted asking me to moderate it. So even though none of these spam comments ever see the light of day, I have to go through them and delete them and I essentially get spammed on my email address.

I have to ask myself what use all this is. I understand that a company that sells something and chooses mailing leaflets as a marketing strategy can benefit from such spam. Even if 0.1% of leaflet recipients actually buy something (that’s only one in a thousand) then they can expect to generate sales by sending stupid amounts of leaflets. The same stands for telephone sales. But does the same apply for the internet? As time goes by people become more aware of all the dodgy stuff out there. Are there actually people clicking on things like “You’ve just won a new laptop, click on asdfghjkl.com to get it”? I would hope not but I’m not so sure. I would hope that people unsuspecting of the evils of the internet are the ones that don’t use it much anyway, as opposed to a telephone or an address which are things everyone has. But I’m probably wrong, because all this spam exists for a reason and it must produce some results, otherwise it would go away.

Any tools we come up with to combat spam is bound to fail, as spammers will keep finding ways to bypass them. Perhaps our only chance is to hope for the time to come for (almost) everyone to be educated enough so that spam is of no use.

Is Agile a blessing or a hoax?

Posted by Yannis Lionis on 04 Jun 2007 | Tagged as: Software

The first time I heard about Agile, I thought it sounded like a load of touchy feely nonsense. Since then I got to practice it, in a really great, open-minded and very capable team, with some members who have been practicing it successfully for a while (we’ve been following the Scrum methodology in particular). I’ve seen the benefits and I can’t imagine going back. It works for the project and it works for the team, and frankly, it seems to me like the best way to work.

However, I’ve seen since then blogs cropping up about how Agile is just a hoax, a fake promise, that’s making a lot of consultants a lot of money but otherwise not doing everyone else any good. Most notable of those was Steve Yegge’s Good Agile, Bad Agile. These views were expressed by bloggers I follow and I believe they generally know what they’re talking about, even if I don’t always agree with them.

So it got me thinking (which is why I read their blogs in the first place): Where lies the truth? Is Agile A Good Thing, or is it a money-making hoax?

I believe the truth lies in the difference between the spirit and the letter of Agile (as with all such things). The spirit of Agile is about self-governing teams, constant customer involvement, team ownership, incremental deliveries and giving-the-customer-what-s/he-really-wants. The letter of the various Agile methodologies is sprints/iterations, stories, standups, estimations, plannings, reviews. So I can understand people’s resentment to the suggestion that keeping to the letter of the law will get you benefits. Introducing daily standups or iterations in your project, while changing nothing else, will yield no results, and the suggestion that it might is absurd. If on the other hand a team is already following the spirit of the law, then they’re already getting the benefits.

Agile is a mindset, not a recipe. Agile practices are there to encourage teams to adopt the correct frame of mind. But make no mistake, the frame of mind is what makes the difference. And it’s not a silver bullet either, it’s just a better way to work and produce software.

“java.lang.OutOfMemoryError: PermGen space” in JBoss

Posted by Yannis Lionis on 01 Jun 2007 | Tagged as: Software

Oh this blasted error. How many times I’ve seen it in JBoss console. How many restarts because of it.

This has been a nuisance for quite a while. Basically what happens is that every time you (re)deploy an application to JBoss, the java process takes up a bit more memory, until after enough redeployments it runs out.

This blog gives a very good explanation of what the PermGen memory error is, how to monitor it and how to modify how much is available for your application.

This however did not solve the problem, as increasing the available PermGen space simply delayed the inevitable. The memory used by JBoss only goes up after each redeployment, so the painful end is unavoidable.

After chasing around the truth in various forums and blogs, each one suggesting a different culprit for the problem (Tomcat, cglib library, the combination of the two, Hibernate, and more) a colleague got a chance at a conference to ask some JBoss guys themselves for an answer. And an answer we got indeed: This problem happens with the Sun JVM. Use another one and it will go away.

So I did. I tried JRockit. And it worked. The problem went away. That simple.

So if you have the same problem, give it a try. It worked for me and it made my day.