Stepping through the pgrade portal

As a Grid veteran, I normally submit jobs using edg-job-*, and at this stage I've almost given up hope that there could be a less painful way of getting jobs onto the Grid. I've tried Ganga in the past, and it was promising, but it didn't work well with the broken MPI on the EGEE grid, so I kind of gave up on it. The latest thing we've installed is the p-grade portal which has been around for a good while and is allegedly getting "mature" now. The first problem after creating an account was getting my cert set up for use in the portal. I had the cert and key on my local machine, and tried to upload them to a MyProxy server to get something the portal could use. At this point, I was asked for the hostname and port number of the MyProxy service. Now, I actually administer the MyProxy server, and still had to ask a colleague which port it ran on. There is no way in the world a user should have to know this, but apparently you can't set defaults in the portal. We're running version 2.5 still so maybe it's fixed in 2.6.

Once I got my cert up and running, I went to submit a job. My first job, the challenging "/bin/hostname" test failed. I didn't expect that. Apparently pgrade uploads a binary from your local machine by default rather than executing something hosted on the remote machine. As my local machine is FC6 and the execute node is SL3, the uploaded hostname binary wouldn't run. So if you wanted to run the hostname program on the remote host, you would have to upload a script which ran /bin/hostname.

The next challenge was how to add input files to the job. It turns out that this is done by adding "ports" to the job node you define. Everything in pgrade is a workflow, so files are ports that allow data to flow between nodes (or from the local machine). It takes a little while to get used to this approach.