I've been messing around trying to get the stage queues in the mps
system working here at RAL so we can limit the impact of switching on
staging on the MSS by limiting the number of concurrent accesses (and
have got it going more or less once I found out that the
--basedir/mps.basedir option is completely ignored in the mps_PreStage
code and fixed it) but I cannot work out how one is suppose to integrate
it with the xrootd/olbd system.
mps_prep seems to take completely different arguments to mps_stage so we
cannot just drop that in as a replacement, more seriously it returns as
soon as the file is placed in the stage queue not when the file is on
disk. Do we need to write yet another wrapper script to translate the
options and hold on until the file has appeared.
The MPS documentation suggest that the olbd interacts directly with the
stage queue but doesn't give any details.
Chris Brew ([log in to unmask]) +44 1235 446326
Particle Physics Department
Rutherford Appleton Laboratory
Chilton, Didcot. Oxfordshire.
OX11 0QX. United Kingdom.