JavaSpace Problems

Over the last couple of years I have been implementing the SAMUEL
(Genetic Algorithm) learning system on top of a JINI/JAVASPACES based
master-worker computation model.  As expected the tasks of evaluating
the members of the current population are put  in the (persistent)
JavaSpace by the master, completed and returned by the workers.  All of
this is done using the Transactiion Manager (persistent Mahalo) to
insure reliability.  Some experiments can take several days to complete
using a cluster, so reliability is a critical issue.  In general
everything has performed very well, but I have had capacity problems
(OutOfMemoryError)  with the JavaSpace (Outrigger) and now allocate
more memory for the JavaSpace's shared-memory JVM.  The reason for this
message is the following problem.
        I have a student running SAMUEL experiments on a small (16-node)
cluster.  Sometimes he starts too many experiments at the same time
with the result that the disk partition on the node where the JavaSpace
is running fills up in one of two ways.  One way is that the
outrigger.log directory contains a large number of (what appear to be)
incremental log files -- normally there is one main log and one or two
incremental logs.
The other way is that, since I save the rmid output into a file, the
JavaSpace repeatedly attempts to reactivate, but produces an exception
and quits -- this eventually fills up the partition as well.  I don't
have a lot of detailed information for you at the moment.  When this
happens I get a lot of complaints, so I need to restore the partition
ASAP.  I'm in the process of setting up a machine separate from the
cluster for hosting the JavaSpace so that I can find out exactly what
is causing this, and how to work around it.
        Any suggestions at this point would be welcome.

        Cheers,
                Bob Daley

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