MPI\_PUBLISH\_NAME(3) Open MPI MPI\_PUBLISH\_NAME(3)

MPI\_Publish\_name — Publishes a service name associated with a port

# [SYNTAX](#SYNTAX)

## [C Syntax](#C_Syntax)

```
#include <mpi.h>
int MPI_Publish_name(const char *service_name, MPI_Info info,


     const char *port_name)
```

## [Fortran Syntax](#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
```

## [Fortran 2008 Syntax](#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
```

# [INPUT PARAMETERS](#INPUT_PARAMETERS)

- **service\_name**: A service name (string).
- **info**: Options to the name service functions (handle).
- **port\_name**: A port name (string).

# [OUTPUT PARAMETER](#OUTPUT_PARAMETER)

•

**ierror**: Fortran only: Error status (integer).

# [DESCRIPTION](#DESCRIPTION)

This routine publishes the pair (*service\_name, port\_name*) so that an application may retrieve *port\_name* by calling MPI\_Lookup\_name &lt;#mpi-lookup-name&gt; with *service\_name* as an argument. 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 &lt;#mpi-open-port&gt;.

# [INFO ARGUMENTS](#INFO_ARGUMENTS)

The following keys for *info* are recognized:

```
Key                   Type      Description
---                   ----      -----------
range                 char *    Scope in which to publish the service


                                name.  See the NAME SCOPE section


                                below.
persistence           char *    How long the published service name is


                                retained.  See below.
```

The *range* info key accepts one of two string values:

[***nspace*: Restrict the operation to processes in the same MPI job (PMIx**](#nspace)

namespace) as the calling process.

*session*: 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 &lt;#mpi-lookup-name&gt;, and MPI\_Unpublish\_name &lt;#mpi-unpublish-name&gt; 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*: Retain the service name until it is explicitly unpublished.

*proc*: Retain the service name until the publishing process terminates.

[***app*: Retain the service name until the publishing application**](#app)

terminates.

[***session*: Retain the service name until the session terminates. This is**](#session)

the default if the *persistence* key is not given.

Any other value for *persistence* results in an error.

# [NAME SCOPE](#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 &lt;#mpi-comm-spawn&gt;. *session* is the default scope.

The same scope must be used to publish, look up, and unpublish a given service name. MPI\_Unpublish\_name &lt;#mpi-unpublish-name&gt; returns an error if the service name is not found in the indicated scope.

As an example of the impact of these scoping rules, consider a job started with **mpirun** – 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 &lt;#mpi-comm-spawn&gt; – call it “job2” – 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.

# [ERRORS](#ERRORS)

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 &lt;#mpi-init&gt;/MPI\_Init\_thread &lt;#mpi-init-thread&gt;, after MPI\_Finalize &lt;#mpi-finalize&gt;, 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 &lt;#mpi-comm-set-errhandler&gt; 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 &lt;#mpi-comm-spawn&gt;/MPI\_Comm\_spawn\_multiple &lt;#mpi-comm-spawn-multiple&gt;. 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** Causes the program to abort all connected MPI processes.
- **MPI\_ERRORS\_ABORT** 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 &lt;#mpi-abort&gt; was called on that communicator. If called on a window or file, acts as if MPI\_Abort &lt;#mpi-abort&gt; 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** Returns an error code to the application.

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

- MPI\_Comm\_create\_errhandler &lt;#mpi-comm-create-errhandler&gt; then MPI\_Comm\_set\_errhandler &lt;#mpi-comm-set-errhandler&gt;
- MPI\_File\_create\_errhandler &lt;#mpi-file-create-errhandler&gt; then MPI\_File\_set\_errhandler &lt;#mpi-file-set-errhandler&gt;
- MPI\_Session\_create\_errhandler &lt;#mpi-session-create-errhandler&gt; then MPI\_Session\_set\_errhandler &lt;#mpi-session-set-errhandler&gt; or at MPI\_Session\_init &lt;#mpi-session-init&gt;
- MPI\_Win\_create\_errhandler &lt;#mpi-win-create-errhandler&gt; then MPI\_Win\_set\_errhandler &lt;#mpi-win-set-errhandler&gt;

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

See the MPI man page &lt;#open-mpi&gt; for a full list of MPI error codes &lt;#open-mpi-errors&gt;.

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

**See also:**

- MPI\_Lookup\_name &lt;#mpi-lookup-name&gt;
- MPI\_Open\_port &lt;#mpi-open-port&gt;

# [Copyright](#Copyright)

2003-2026, The Open MPI Community

September 16, 2026

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Document: MPI_Publish_name(3) from openmpi 5.0.11-r1 (Chainguard OS)
Source: https://github.com/open-mpi/ompi
