I've fallen behind on my journal entries. Cope.
Brief synopsis on dissertation stuff: got the threaded boot "fully" working. It still sometimes hangs in a very large boot (e.g., .helios scale boots, ~148 hosts or so) near the end. I suspect that someone drops out of the mesh before the boot finishes, but I haven't had a controlled failure yet to check the logs and see what is really going on. Additionally, sometimes a given node drops out when we do arbitrarily large numbers of children (e.g., at 12, foster.helios.nd.edu somehow decides that it doesn't want to boot. I don't know if this is an artifact of foster's parent screwing up [e.g., running out of file descriptors], or if foster itself somehow legitimately getting hosed. It's hard to tell, too, because all of these machines are actively being used when I do my tests :-).
I had to spend a good amount of time writing the jmesh algorithm into the code. I was using the Boost Graph Library, which was written by Rich Lee and Jeremy Siek here in the lab. However, as is always a danger with developing code, the APIs and concepts are continually changing, and the docs that I have (i.e., the book that Jeremy is writing on the BGL) is not consistent with what is available for public consumption at www.boost.org. Additionally, Jeremy's local CVS copy changes stuff even further. As a result, I spent a long time before I actually got it working. Arf.
However, I did come up with an iterative method to generate a list of edges in a jmesh that doesn't use any lookups at all
-- it just generates pairs of vertex numbers, and then we smush those into the constructor of a BGL graph. As such, it's considerably faster than the version that I wrote before -- the prior version would go to each vertex, check how many edges it had, determine if it needed more, etc., etc. This new version just does bookkeeping as it goes along with a small number of integer variables, and All is Well.
Now that I've finally got that working, I can add the stuff for all the nodes to make the connectivity implied in the jmesh, drop the boot tree connectivity, and then sit there waiting for commands. Not for now...
Unfortunately, however, Bill from NIST sent around an e-mail today saying that we'll be having a conference call about the SC'2000 IMPI demo on Friday morning. Doh!!! I haven't done butkis on IMPI yet. I've got to do the following:
- Finish implementing the attribute color stuff per IMPI section 2.5
- Implement
MPI_BARRIERon IMPI communicators - Make LAM/MPI compliant with the IMPI errata
- Get the
pmandeldemo code working with a few instances of LAM
It would be Really Good to get this all working by the call on Friday so that forward progress can be claimed...
Sidenote: it's really been quite a while since I've worked on IMPI. I am finding out how much I forget about how it works. Doh!
Saw a great quote in the IMPI code today:
Honk if you love silence.
I even remember putting that comment in there. Classic. :-)
Found two interesting python MPI projects:
I don't think that either project's main goal is formal python MPI bindings, but instead have some main "real" project that is [at least partly] in python, and they wanted to use MPI. I conversed with the sourceforge project author (at Lawrence Livermore); they're actively using it. I asked if there will ever be a formal release (all that's on sourceforge is CVS, not a real distribution). Haven't heard back yet.
Tony Hagale got my journal up and running. Woo hoo! Not entirely pain-free, though. Had to upgrade his C++ compiler, etc. He had some initial problems with quoting, as well. Not quite sure if that was a local configuration issue or a bug in my code ('cause it doesn't happen to me :-).
Started running MojoNation on squyres.com. Speaking from a distributed/crypto standpoint, that's some really cool shit!
Much work to do to get IMPI into shape. Miles to code before I sleep. Rusty will be here all day tomorrow; he's giving a talk on MPICH's daemon, and then Lummy and I are going to the LaSalle grill with him for dinner (yummy). Should be quite interesting.