MPI_PUBLISH_NAME(3)

🌸 NAME 🌸

MPI_Publish_name β€” Publishes a service name associated with a port

Okay bestie, this is the Open MPI manual page for MPI_Publish_name, and it’s literally the β€œmake my service name findable” era. πŸ’…βœ¨


✨ SYNTAX ✨

πŸ’» C Syntax

          #include <mpi.h>

          int MPI_Publish_name(const char *service_name, MPI_Info info,
               const char *port_name)

🧚 Fortran Syntax

          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_PUBLISH_NAME(SERVICE_NAME, INFO, PORT_NAME, IERROR)
               CHARACTER*(*)   SERVICE_NAME, PORT_NAME
               INTEGER         INFO, IERROR

πŸ¦‹ Fortran 2008 Syntax

          USE mpi_f08
          MPI_Publish_name(service_name, info, port_name, ierror)
               TYPE(MPI_Info), INTENT(IN) :: info
               CHARACTER(LEN=*), INTENT(IN) :: service_name, port_name
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

πŸ’– INPUT PARAMETERS πŸ’–

  • service_name β€” A service name (string). πŸŽ€
  • info β€” Options to the name service functions (handle). ✨
  • port_name β€” A port name (string). πŸ¦‹

πŸŽ€ OUTPUT PARAMETER πŸŽ€

  • ierror β€” Fortran only: Error status (integer). πŸ’…

🌈 DESCRIPTION 🌈

So this routine publishes the pair (service_name, port_name) so that an application may retrieve port_name by calling MPI_Lookup_name with service_name as an argument. That’s the whole vibe: name goes in, lookup can later pull the port back out. πŸ”₯

It is an error to publish the same service_name twice, or to use a port_name argument that was not previously opened by the calling process via a call to MPI_Open_port. No cap, that’s an error. πŸ’€

πŸ”₯ INFO ARGUMENTS πŸ”₯

The following keys for info are recognized:

  • range β€” Type: char *. Scope in which to publish the service name. See the NAME SCOPE section below. 🧭
  • persistence β€” Type: char *. How long the published service name is retained. See below. ⏳

The range info key accepts one of two string values:

  • nspace β€” Restrict the operation to processes in the same MPI job (PMIx namespace) as the calling process.
  • session β€” Apply the operation across all processes in the same session.

If the info argument is MPI_INFO_NULL, or is a valid info object that does not contain a range key, session scope is used. Because MPI_Publish_name, MPI_Lookup_name, and MPI_Unpublish_name all share this default, a name published with MPI_INFO_NULL is found by a lookup with MPI_INFO_NULL. 🫢

Any other value for range results in an error. 🚨

The persistence info key accepts one of four string values:

  • indef β€” Retain the service name until it is explicitly unpublished.
  • proc β€” Retain the service name until the publishing process terminates.
  • app β€” Retain the service name until the publishing application terminates.
  • session β€” Retain the service name until the session terminates. This is the default if the persistence key is not given.

Any other value for persistence results in an error. πŸ›‘


🧭 NAME SCOPE 🧭

Open MPI supports two name scopes, selected by the range info key: nspace and session.

nspace scope restricts the (service_name, port_name) pair to processes in the publisher’s own MPI job, i.e., processes sharing the publisher’s PMIx namespace.

session scope makes the pair visible to every process in the same PMIx session. This includes jobs started by separate mpirun invocations that share a persistent DVM or scheduler allocation, as well as jobs created via MPI_Comm_spawn. session is the default scope. 🌈

The same scope must be used to publish, look up, and unpublish a given service name. MPI_Unpublish_name returns an error if the service name is not found in the indicated scope. πŸ‘‘

As an example of the impact of these scoping rules, consider a job started with mpirun β€” call it job1. A process in job1 publishes a service/port pair using nspace scope. A process in a job that job1 subsequently starts via MPI_Comm_spawn β€” call it job2 β€” is in a different namespace, and so cannot retrieve that pair. Had job1 published with session scope (the default), processes in job2 could retrieve it, as could processes in any other job sharing the same session. πŸ¦‹


πŸ’€ ERRORS πŸ’€

Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI_COMM_SELF and will call the associated MPI error handler. When MPI_COMM_SELF is not initialized (i.e., before MPI_Init/MPI_Init_thread, after MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info key to MPI_Comm_spawn/MPI_Comm_spawn_multiple. If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is called for all other MPI functions.

Open MPI includes three predefined error handlers that can be used:

  • MPI_ERRORS_ARE_FATAL β€” Causes the program to abort all connected MPI processes. πŸ’€
  • MPI_ERRORS_ABORT β€” An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if MPI_Abort was called on that communicator. If called on a window or file, acts as if MPI_Abort was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.
  • MPI_ERRORS_RETURN β€” Returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

  • MPI_Comm_create_errhandler then MPI_Comm_set_errhandler
  • MPI_File_create_errhandler then MPI_File_set_errhandler
  • MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init
  • MPI_Win_create_errhandler then MPI_Win_set_errhandler

Note that MPI does not guarantee that an MPI program can continue past an error. 😭

See the MPI man page for a full list of MPI error codes.

See the Error Handling section of the MPI-3.1 standard for more information.


πŸ”Ž SEE ALSO πŸ”Ž

  • MPI_Lookup_name
  • MPI_Open_port

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Catch you later, bestie 🫢 β€” this is the Open MPI page, dated Sep 11, 2026, with footer MPI_PUBLISH_NAME(3). πŸ’…βœ¨

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