Dear Jan,
Sorry for the late reply.
There are two questions in your posts.
- Using PROOF to process data not in ROOT TTree format
PROOF was designed to process ROOT trees and in its default mode it is steered by the tree dataset.
However, PROOF has also a mode where the Process method of the selector is called a certain number of times, distributed between workers (the one you were playing with).
This mode can be adapted to process other files. The ‘event’ or ‘entry’ unit will then be to process one file, from a list that you can pass in the input list.
You will have to take care to open and close the file. This can certainly be done. I can provide an example, which could be useful also for others.
- Problem with the simple test example
There is a fundamental difference between the case that works (which you call ‘compilation with ACliC’) and the other one. In the first case, the source files for the selectors are sent to the workers and the compilation is done (in an optimized way) by each of them. In the second the selector object is created in the main process (the one where you start the PROOF session) and sent over to the worker processes. This requires the object to be streamable, which does not look to be the case in your example.
I’ll try to run your example and find out exactly, but I suspect something related to that.
G. Ganis