So we went ahead and decided that we need this feature. We're planning to have a lot of people running huge pipelines, ones that work best on one node, and there's no reason to do all this writing to any shared file system when it works best on one node using /tmp/ for intermediate step data. So I've been working on that.

So far I've made the checkbox for using one node (in run.mako). In workflow.py I catch this and set a new variable in each step of the workflow called use_one_node, if checkbox is checked.

Now I'm trying to find where jobs are run, so that I can put the logic in for getting a node to run on, and setting that as a variable on each step. Could you point me in the direction of the files/classes associated with running the history's jobs, and getting nodes (or sending jobs to condor?)?