Hello all,
Does anyone have any experience in reading and defining new
NetCDF variables midway through a multiple processor MPI program? I've
experienced a very strange bug:
I have a MPI program where each processor reads in data from multiple
NetCDF variables. If a variable is missing, one of the processors then
defines the new variable while the other processors halt. Once the
variable is defined, all of the processors move forward in the program.
If the newly defined variable is small, this works with no problems.
However, if the definition of the new variables takes a considerable
amount of time, then the other processors actually _forget_ the data
they previously read in. How weird is that?
I am using the NO_Fill mode to define the variables, but it still takes
a long time. The variable could be huge, though (500+ MB).
There's an easy-to-implement solution (define first, then read),
but I was curious if anyone has had a similar problem and what causes it?
Thanks,
Howard Salis
Dept Chemical Eng. & Materials Science
University of Minnesota
