It’s been a while since I last posted, but I thought I should update the ‘world’ (i.e. myself) on some of the more recent accomplishments I have made towards the replay and ubicomp testbed systems I am working on.
1) I have successfully created easy methods of getting content from real live data streams and mocked up datastreams using eventheap as my tuplespace of choice.
2) I successfully built a bunch of ‘middle-ware’ so that my python code can talk to jython code and which in turn talks to the EventHeap over it’s native binary protocol. I am confident I could write a Python wrapper, but for the time-being this works fine, and also sufficiently abstracts publishing sensor information from the platform where sensor data is to be published.
3) I have been playing a lot with Pyro (http://pyro.sourceforge.net ) as a really simple replacement for XMLRPC. It solves a few problems I had using XMLRPC for example provides a name-server system so that services can ‘just run’ and you don’t have to worry about matching up ports to service names, and using ‘connections’ with a binary protocol reducing the overhead of parsing XML and using HTTP to manage connections. It also created new problems, like requiring all exported objects to inherit from a common base-class, and not being as compatible with other RPC mechanisms in other languages, Pyro is still unstable for Jython.
And I think with that I’ll call it a night, there’s a lot of interesting discoveries to share. I’ve leave you with this. If your running the latest Jython or even 2.5a3 you better be running the latest java JRE, I had a problem where my jython RPC server took a few minutes to load ate up 100% CPU and timed out responding to connections. I tried a variety of approaches to solve this problem, and finally just installed the lasted JDK and JRE (I was using the built in Sun distributed ubuntu java packages..) — Note to others — Just get the JDK off of sun’s website, trying to debug something because the JRE is buggy is not the problem you want to run into.
