Archive for August, 2009
Recently I got into the situation that somebody used some interface a way it was not designed for and so created an out-of-memory situation which couldn’t be handled by the engine itself. So now I got the case that one client block the complete service due to invalid requests which he shouldn’t do in the first place.
In the short term there seemed to be only one solution, block the client. So I began to search around how this could be done.
The easiest way to achieve this would be to change the authentication for this service. Unluckily this service is used by a lot of other clients, so I can’t change it out of the blue. Next thing that came to my mind was using the underlying tomcat to do some IP-based blocking. After some searching around I gave that one up. Tibco has a really complex deployment model for BusinessWorks so I wasn’t able to even find the process-specific section for the tomcat engine.
After some searching around in the documentation (actually several hours – hooray to a usable documentation) I found some parameter which allows you to block IPs with some TRA-file parameters. In case you want to look it up yourself it is in the BusinessWorks documentation under ‘Administration’ -> Chapter 8 ‘Custom Engine Properties’ -> ‘Available Custom Engine Properties’ (and another hooray to the excellent formatting – Note to Tibco: HTML has tags, so you can do more with the content then continuous text – even some breaks would enhance the experience).
So back to the point:
Both tags are rather self explanatory so you can use right away. Tibco says you can use it with a single IP, a list of IPs (comma-separated) or regular expression. As stated before this highlight of a documentation doesn’t say what reg-exp syntax means. I guess Tibco means they use the Tomcat engine for evaluation of these values an that means they use the Java syntax described here.
A little time ago I started experimenting with some of the new HTML 5 features. Some seam pretty impressive although some a rather unnecessary in my opinion. But one thing got me really hooked – the HTML canvas.
A lot of people out there use services like delicious where you tag you favorite sites and make this available to other users. Now I started to grab that data and began to build a massive tag cloud. After some time the site collected hundreds of thousands of links with their corresponding tags. So now you can start on the site and search for tags which interests you. These search tags will then be correlated against the cloud database and you get the most active links for your tags. So here is an example.
Let’s say you are interested in a tomcat tutorial.
Of course those results will be a link to the concrete tutorial (not just the entry page).
So far to the official part. For me this is more of a fun project. I prefer to start with some random tag and then wander around. It’s more like browsing, cause you start at points that you don’t already know. You have the chance to break out of your existing network of most used sites and see something new.
So have fun with it.
PS: For the implementation part – if you have any questions, just ask. I’m planning to explain some details about how it works on some later posts.