January 16th Report

Root Client Supports Shared Eventing and Shared Display Type Collaborations.

So far the HEP Data Analysis Client that we have uses a shared event model for collaboration. All the clients perform the fitting and merging of histograms received from servers. This is a very useful feature if different collaborative clients need to "fit" different models to the data received to them. However, if the same model is used by all the clients, then a shared display type collaboration would be the right solution.

I added a feature to the client so that it publishes its current histogram as an image (after fitting and merging) to a topic using the NB's C++ client. I also developed a separate program to simply subscribe to a topic and display the images received over the pub/sub communication channel. This program is very lightweight as its task is merely showing images in a canvas as an when they are received.

This implementation enables the shared display type collaboration among the participating clients to an experiment. Physicists who just need to see the results of an experiment can simply use the shared display client.

Currently all the clients subscribed to a particular topic will receive the histogram images. However, with the introduction of the "agents" , which keep track of on going experiments, to the system these settings can be controlled.