Environment Variables 

I_MPI_HYDRA_HOST_FILE 

Set the host file to run the application.

Syntax

I_MPI_HYDRA_HOST_FILE=<arg> 

Deprecated Syntax

HYDRA_HOST_FILE=<arg> 

Arguments 

<arg> 

String parameter

<hostsfile> 

Full or relative path to the host file

Description

Set this environment variable to specify the hosts file.

I_MPI_HYDRA_DEBUG 

Print out the debug information.

Syntax

I_MPI_HYDRA_DEBUG=<arg>

Arguments 

<arg> 

Binary indicator

enable | yes | on | 1

Turn on the debug output

disable | no | off | 0

Turn off the debug output. This is the default value

Description

Set this environment variable to enable the debug mode.

I_MPI_HYDRA_ENV 

Control the environment propagation.

Syntax

I_MPI_HYDRA_ENV=<arg>

Arguments 

<arg> 

String parameter

all 

Pass all environment to all MPI processes

Description

Set this environment variable to control the environment propagation to the MPI processes. By default, the entire launching node environment is passed to the MPI processes. Setting this variable also overwrites environment variables set by the remote shell.

I_MPI_JOB_TIMEOUT, I_MPI_MPIEXEC_TIMEOUT  

(MPIEXEC_TIMEOUT)

Set the timeout period for mpiexec.hydra.

Syntax

I_MPI_JOB_TIMEOUT=<timeout>

I_MPI_MPIEXEC_TIMEOUT=<timeout>

Deprecated Syntax

MPIEXEC_TIMEOUT=<timeout>

Arguments

<timeout> 

Define mpiexec.hydra timeout period in seconds

<n> >= 0

The default timeout value is zero, which means no timeout.

Description

Set this environment variable to make mpiexec.hydra  terminate the job in <timeout> seconds after its launch. The <timeout> value should be greater than zero. Otherwise the environment variable setting is ignored.

Note:

Set the I_MPI_JOB_TIMEOUT environment variable in the shell environment before executing the mpiexec.hydra command. Do not use the -genv or -env options to set the <timeout> value. Those options are used for passing environment variables to the MPI process environment.

I_MPI_JOB_TIMEOUT_SIGNAL 

(MPIEXEC_TIMEOUT_SIGNAL)

Define the signal to be sent when a job is terminated because of a timeout.

Syntax

I_MPI_JOB_TIMEOUT_SIGNAL=<number>

Deprecated Syntax

MPIEXEC_TIMEOUT_SIGNAL=<number>

Arguments

<number> 

Define signal number

<n> > 0

The default value is 9 (SIGKILL)

Description

Define a signal number sent to stop the MPI job if the timeout period specified by the I_MPI_JOB_TIMEOUT environment variable expires. If you set a signal number unsupported by the system, the mpiexec.hydra operation prints a warning message and continues the task termination using the default signal number 9 (SIGKILL). 

I_MPI_JOB_ABORT_SIGNAL 

Define a signal to be sent to all processes when a job is terminated unexpectedly.

Syntax

I_MPI_JOB_ABORT_SIGNAL=<number>

Arguments

<number> 

Define signal number

<n> > 0

The default value is 9 (SIGKILL)

Description

Set this environment variable to define a signal for task termination. If you set an unsupported signal number, mpiexec.hydra prints a warning message and uses the default signal 9 (SIGKILL). 

I_MPI_JOB_SIGNAL_PROPAGATION 

(MPIEXEC_SIGNAL_PROPAGATION)

Control signal propagation.

Syntax

I_MPI_JOB_SIGNAL_PROPAGATION=<arg>

Deprecated Syntax

MPIEXEC_SIGNAL_PROPAGATION=<arg>

Arguments

<arg> 

Binary indicator

enable | yes | on | 1 

Turn on propagation

disable | no | off | 0

Turn off propagation. This is the default value 

Description

Set this environment variable to control propagation of the signals (SIGINT, SIGALRM, and SIGTERM). If you enable signal propagation, the received signal is sent to all processes of the MPI job. If you disable signal propagation, all processes of the MPI job are stopped with the default signal 9 (SIGKILL).

I_MPI_HYDRA_BOOTSTRAP

Set the bootstrap server.

Syntax

I_MPI_HYDRA_BOOTSTRAP=<arg>

Arguments

<arg> 

String parameter  

ssh

Use secure shell. This is the default value

rsh

Use remote shell

pdsh

Use parallel distributed shell

fork

Use fork call

slurm

Use SLURM* srun command

ll

Use LoadLeveler* llspawn.stdio command

lsf

Use LSF  blaunch command

sge

Use Oracle Grid Engine* qrsh  command

jmi

Use Job Manager Interface (tighter integration)

Description

Set this environment variable to specify the bootstrap server.

Note:

Set the I_MPI_HYDRA_BOOTSTRAP environment variable in the shell environment before executing the mpiexec.hydra command. Do not use the -env option to set the <arg> value. This option is used for passing environment variables to the MPI process environment.

I_MPI_HYDRA_BOOTSTRAP_EXEC 

Set the executable to be used as a bootstrap server.

Syntax

I_MPI_HYDRA_BOOTSTRAP_EXEC=<arg>

Arguments

<arg> 

String parameter

<executable>

The name of the executable

Description

Set this environment variable to specify the executable to be used as a bootstrap server.

I_MPI_HYDRA_RMK 

Use the resource management kernel.

Syntax

I_MPI_HYDRA_RMK=<arg>

Arguments

<arg> 

String parameter

<rmk> 

Resource management kernel. The only supported value is pbs

Description

Set this environment variable to use the pbs resource management kernel.  Intel® MPI Library only supports pbs.

I_MPI_HYDRA_PMI_CONNECT

Define the processing method for PMI messages.

Syntax 

I_MPI_HYDRA_PMI_CONNECT=<value>

Arguments

<value> 

The algorithm to be used  

nocache

Do not cache PMI messages.

cache

Cache PMI messages on the local pmi_proxy management processes to minimize the number of PMI requests. Cached information is automatically propagated to child management processes.

lazy-cache

cache mode with on-demand propagation. This is the default value. 

Description

Use this environment variable to select the PMI messages processing method.

I_MPI_PERHOST

Define the default settings for the -perhost option in the mpiexec and mpiexec.hydra command.

Syntax 

I_MPI_PERHOST=<value>

Arguments 

<value> 

Define a value that is used for the -perhost option by default 

integer > 0

Exact value for the option

all

All logical CPUs on the node

allcores

All cores (physical CPUs) on the node 

Description

Set this environment variable to define the default setting for the -perhost option. The -perhost option implied with the respective value if the I_MPI_PERHOST environment variable is defined.

I_MPI_JOB_TRACE_LIBS 

Choose the libraries to preload through the -trace option. 

Syntax

I_MPI_JOB_TRACE_LIBS=<arg>

Deprecated Syntax

MPIEXEC_TRACE_LIBS=<arg>

Arguments 

<arg> 

String parameter

<list>

Blank separated list of the libraries to preload. The default value is vt

Description

Set this environment variable to choose an alternative library for preloading through the -trace option. 

I_MPI_JOB_CHECK_LIBS 

Choose the libraries to preload through the -check_mpi option. 

Syntax

I_MPI_JOB_CHECK_LIBS=<arg>

Arguments 

<arg> 

String parameter

<list>

Blank separated list of the libraries to preload. The default value is vtmc

Description

Set this environment variable to choose an alternative library for preloading through the -check_mpi option. 

I_MPI_HYDRA_BRANCH_COUNT 

Set the hierarchical branch count.

Syntax

I_MPI_HYDRA_BRANCH_COUNT =<num>

Arguments 

<num> 

Number

<n> >= 0

  • The default value is -1 if less than 128 nodes are used. This also  means that there is no hierarchical structure

  • The default value is 32 if more than 127 nodes are used

Description

Set this environment variable to restrict the number of child management processes launched by the mpiexec.hydra operation or by each pmi_proxy management process.

I_MPI_HYDRA_PMI_AGGREGATE 

Turn on/off aggregation of the PMI messages.

Syntax  

I_MPI_HYDRA_PMI_AGGREGATE=<arg>

Arguments 

<arg>  

Binary indicator

enable | yes | on | 1

Enable PMI message aggregation. This is the default value 

disable | no | off | 0

Disable PMI message aggregation 

Description

Set this environment variable to enable/disable aggregation of PMI messages .

I_MPI_HYDRA_GDB_REMOTE_SHELL 

Set the remote shell command to run GNU* debugger.

Syntax

I_MPI_HYDRA_GDB_REMOTE_SHELL=<arg>

Arguments

<arg> 

String parameter

ssh 

Secure Shell (SSH). This is the default value

rsh  

Remote shell (RSH) 

Description

Set this environment variable to specify the remote shell command to run the GNU* debugger on the remote machines. You can use this environment variable to specify any shell command that has the same syntax as SSH or RSH. 

I_MPI_ HYDRA_JMI_LIBRARY

Define the default setting of the JMI library.

Syntax 

I_MPI_HYDRA_JMI_LIBRARY=<value>

Arguments 

<value> 

Define a string value, name, or path to JMI dynamic library 

libjmi_slurm.so.1.1 | libjmi_pbs.so.1.0

Set the library name or full path to library name. The default value is libjmi.so 

Description

Set this environment variable to define the JMI library to be loaded by the Hydra* processor manager. Set the full path to the library if the path is not mentioned in the LD_LIBRARY_PATH environment variable. If the mpirun  command is used, you do not need to set this environment variable. The JMI library is automatically detected and set.

I_MPI_HYDRA_IFACE 

Set the network interface.

Syntax

I_MPI_HYDRA_IFACE=<arg>

Arguments

<arg> 

String parameter

<network interface> 

The network interface configured in your system

Description

Set this environment variable to specify the network interface to use. For example, use -iface ib0, if the IP emulation of your InfiniBand* network is configured on ib0.

I_MPI_HYDRA_DEMUX 

Set the demultiplexer (demux) mode.

Syntax

I_MPI_HYDRA_DEMUX=<arg>

Arguments

<arg> 

String parameter

poll

Set poll as the multiple I/O demultiplexer (demux) mode engine. This is the default value.

select 

Set select as the multiple I/O demultiplexer (demux) mode engine

Description

Set this environment variable to specify the multiple I/O demux mode engine. The default is Poll

I_MPI_HYDRA_CLEANUP

Control the creation of the default mpicleanup input file.

Syntax 

I_MPI_HYDRA_CLEANUP=<value>

Arguments 

<value> 

Binary indicator

enable | yes | on | 1

Enable the mpicleanup input file creation

disable | no | off | 0

Disable the mpicleanup input file creation. This is the default value

Description

Set the I_MPI_HYDRA_CLEANUP environment variable to create the input file for the mpicleanup utility. 

I_MPI_TMPDIR 

(TMPDIR)

Set the temporary directory.

Syntax

I_MPI_TMPDIR=<arg>

Arguments

<arg> 

String parameter

<path> 

Set the temporary directory. The default value is /tmp 

Description

Set this environment variable to specify the temporary directory to store the mpicleanup input file. 

I_MPI_JOB_RESPECT_PROCESS_PLACEMENT

Specify whether to use the job scheduler provided process-per-node parameter.

Syntax

I_MPI_JOB_RESPECT_PROCESS_PLACEMENT=<arg>

Arguments 

<value> 

Binary indicator

enable | yes | on | 1

Use the process placement provided by job scheduler. This is the default value

disable | no | off | 0

Do not use the process placement provided by job scheduler

Description

If you set I_MPI_JOB_RESPECT_PROCESS_PLACEMENT=enable, then Hydra process manager uses PPN provided by job scheduler.

If you set I_MPI_JOB_RESPECT_PROCESS_PLACEMENT = disable, then Hydra process manager uses PPN provided in command line option or using I_MPI_PERHOST environment variable.