Every now and then I get involved in Customer Proof of Concepts. A Proof of Concept (POC) is, according to Wikipedia, something like a demonstration of feasibility of a certain idea, concept or theory.
POC: Piece Of Cake or Point Of Contradiction?
Oracle Stretched Cluster with VPLEX (update)
One request I got back after my series on Oracle RAC stretched clusters is if I could summarize again why anybody would choose VPLEX for storage replication over other solutions. My attempt was to describe the principles of VPLEX in enough detail for techies to understand it. For non-geeks, I will try to explain it as brief as possible.
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Data Guard or Storage based replication?
A comparison between Oracle (Active) Data Guard and EMC replication for disaster recovery purposes
This is an article I wrote a while ago for customers’ Database Administrators (DBAs) and application managers, that helps them in selecting the right Disaster Recovery tools for their business applications.
It is slightly modified to update new insights and to make it more readable on the web.
The Dutch Diginotar Hack
Slightly off-topic here considering my normal focus on business applications (or actually, maybe not, decide for yourself).
On the Dutch ICT news sites it is currently a big topic. And the impact for the whole internet is probably still underestimated. What happened? On August 29 2011, I read a news post on webwereld.nl (a Dutch ICT news site) that Iran (actually it seemed to be Iranians but this is still not sure) could tap internet traffic to GMail. This happened because they used an SSL certificate that was signed by the Dutch Certificate Authority Diginotar. Diginotar is a Dutch company providing PKI (Public Key Infrastructure) “certificates” for secure connections, both for regular commercial customers and for the Dutch government. Ouch!
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Monkey Business
Maybe you have heard the story of the Monkey Experiment. It is about an experiment with a bunch of monkeys in a cage, a ladder, and a banana. At a certain point one of the monkeys sees the banana hanging up high, starts climbing the ladder, and then the researcher sprays all monkeys with cold water. The climbing monkey tumbles down before even getting the banana, looks puzzled, wait until he’s dry again and his ego back on its feet. He tries again, same result, all monkeys are sprayed wet. Some of the others try it a few times until they learn: don’t climb for the banana or you will get wet and cold.
The second part of the experiment becomes more interesting. The researcher removes one of the monkeys and replaces him with a fresh, dry monkey with an unharmed ego. After a while he spots the banana, wonders to himself why the other monkeys are so stupid not to go for the banana, and gives it a try. But when reaching the ladder, the other monkeys kick his ass and make it very clear he is not supposed to do so. After the new monkey is conditioned not to go for the banana, the researcher replaces the “old” monkeys, one by one, with new ones. Every new monkey goes for the banana until he learns not to do so.
Eventually the cage is full of monkeys who know that they are not allowed to climb the ladder to get the banana. None of them knows why – it’s just the way it is and always has been…
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