Usage
startMPIcluster(count, verbose=FALSE, workdir=getwd(), logdir=workdir,
maxcores=1, includemaster=TRUE, bcast=TRUE,
comm=if (mpi.comm.size(0) > 1) 0 else 3,
intercomm=comm + 1, mtag=10, wtag=11,
defaultopts=list())Arguments
count
Number of workers to spawn. If you start your
script using mpirun, then you don't really need to use
the count argument, because startMPIcluster will
try to do something reasonable. To be more specific, if
comm is 0, then it will set count to
mpi.comm.size(0) - 1. In fact, it is an error to set
count to any other value. If comm is greater than
0, it will determine the number of processes to spawn by calling
mpi.universe.size(). If that value is greater than one, then
count is set to one less. If that value is equal to one, then
count is arbitrarily set to 2.
Note that if you've started the script without
mpirun, than mpi.universe.size() will always return
1, so count will default to 2.
verbose
Indicates if verbose messages should be enabled.
Defaults to FALSE.
workdir
Working directory of the cluster workers.
Defaults to the master's working directory.
logdir
Directory to put the worker log files.
Defaults to workdir.
maxcores
Maximum number of cores for workers to use.
Defaults to 1.
includemaster
Indicates if the master process should be counted
as a load on the CPU.
This will effect how many cores will be used on the local machine by
mclapply, if a worker process is started on the local machine.
Defaults to TRUE.
bcast
Indicates if a true MPI broadcast should be used to send
shared “job” data to the workers. If FALSE is specified, the
data is sent by separate messages to each worker, which is sometimes
faster than using a broadcast. So this option really controls whether
to do a real or an emulated broadcast. Defaults to TRUE.
comm
Communicator number to use. A value of 0 means to use
non-spawn mode, which means the cluster workers are started using
mpirun/ortrun with more than one worker. A value of 1 or more
forces spawn mode. Multiple clusters can be started by using different
values for comm and intercomm. It defaults to 0
if mpi.comm.size(0) > 1, otherwise 3.
intercomm
Inter-communicator number. Defaults to comm + 1.
mtag
Tag to use for messages sent to the master.
Do not use this option unless you know what you're doing, or
your program will very likely hang.
Defaults to 10.
wtag
Tag to use for messages sent to the workers.
Do not use this option unless you know what you're doing, or
your program will very likely hang.
Defaults to 11.
defaultopts
A list containing default values to use for some
of the .options.mpi options.
These options include: chunkSize, info,
profile, bcastThreshold, forcePiggyback,
nocompile, and seed.