HP-MPI User's Guide (11th Edition)

Glossary 311
Glossary
application In the context of HP-MPI, an
application is one or more executable
programs that communicate with each other
via MPI calls.
asynchronous Communication in which
sending and receiving processes place no
constraints on each other in terms of
completion. The communication operation
between the two processes may also overlap
with computation.
bandwidth Data transmission capacity of a
communications channel. The greater a
channel’s bandwidth, the more information
it can carry per unit of time.
barrier Collective operation used to
synchronize the execution of processes.
MPI_Barrier blocks the calling process until
all receiving processes have called it. This is
a useful approach for separating two stages
of a computation so messages from each
stage are not overlapped.
blocking receive Communication in which
the receiving process does not return until
its data buffer contains the data transferred
by the sending process.
blocking send Communication in which
the sending process does not return until its
associated data buffer is available for reuse.
The data transferred can be copied directly
into the matching receive buffer or a
temporary system buffer.
broadcast One-to-many collective operation
where the root process sends a message to all
other processes in the communicator
including itself.
buffered send mode Form of blocking send
where the sending process returns when the
message is buffered in application-supplied
space or when the message is received.
buffering Amount or act of copying that a
system uses to avoid deadlocks. A large
amount of buffering can adversely affect
performance and make MPI applications less
portable and predictable.
cluster Group of computers linked together
with an interconnect and software that
functions collectively as a parallel machine.
collective communication Commu-
nication that involves sending or receiving
messages among a group of processes at the
same time. The communication can be
one-to-many, many-to-one, or many-to-many.
The main collective routines are MPI_Bcast,
MPI_Gather, and MPI_Scatter.
communicator Global object that groups
application processes together. Processes in
a communicator can communicate with each
other or with processes in another group.
Conceptually, communicators define a
communication context and a static group of
processes within that context.
context Internal abstraction used to define
a safe communication space for processes.
Within a communicator, context separates
point-to-point and collective
communications.
data-parallel model Design model where
data is partitioned and distributed to each
process in an application. Operations are
performed on each set of data in parallel and
intermediate results are exchanged between
processes until a problem is solved.