Launching MPD Daemons

Intel MPI Library uses a Multi-Purpose Daemon (MPD) job startup mechanism. To run programs compiled with mpicl mpicc (or related) commands, you must first set up MPD daemons. It is strongly recommended that you start and maintain your own set of MPD daemons, as opposed to having the system administrator start up the MPD daemons once for use by all users on the system. This setup enhances system security and gives you greater flexibility in controlling your execution environment.

How to Set Up MPD Daemons

The command for launching multi-purpose daemons on Windows* OS is called “smpd”, which is an acronym for simple multi-purpose daemons. When Intel MPI Library is installed on a cluster, the smpd service is automatically started. On the master node of your cluster, type the following command in the command prompt:

clusrun smpd-status | more

For a four-node cluster, you may see a response that looks as follows:

---------------------clusternode01 returns 0----------------------- 
smpd running on clusternode01 
---------------------clusternode02 returns 0----------------------- 
smpd running on clusternode02 
---------------------clusternode03 returns 0----------------------- 
smpd running on clusternode03 
---------------------clusternode04 returns 0----------------------- 
smpd running on clusternode04

In this example, the four nodes of the cluster are called clusternode1, clusternode2, clusternode3, and clusternode4.

You can stop all smpd daemons from the master node using the command:

clusrun smpd -uninstall

To restart the daemons from the master node, enter the command:

clusrun smpd-install

or

clusrun smpd -regserver

To verify that the smpd daemons are running properly, simply repeat the command:

clusrun smpd-status | more

To shut down the smpd daemons, on all nodes of the cluster, enter the command:

clusrun smpd-remove

or

clusrun smpd-unregserver

or

clusrun smpd-uninstall

To see the options for the smpd command, enter:

smpd-help

Setting Up MPD Daemons

1. Set up environment variables with appropriate values and directories, for example, in the .cshrc or .bashrc files. At a minimum, set the following environment variables. Ensure that the PATH variable includes the following:

   • The <mpi-install-dir>/bin directory.

   • Directory for Python* version 2.2 or greater.

   • If you are using Intel® C++ Compiler and/or Intel® Fortran Compiler, ensure that the LD_LIBRARY_PATH variable contains the directories for the compiler library. You can set this variable by using the *vars.[c]sh scripts included with the compiler. Set any additional environment variables your application uses.

2. Create a $HOME/.mpd.conf file that contains your MPD password. Your MPD password is not the same as any Linux login password, but rather is used for MPD only. It is an arbitrary password string that is used only to control access to the MPD daemons by various cluster users. To set up your MPD password:

   secretword=<your mpd secretword> 

   Do not use any Linux login password for <your mpd secretword> . An arbitrary <your mpd secretword>  string only controls access to the MPD daemons by various cluster users.

3. Set protection on the file so that you have read and write privileges and ensure that the $HOME/.mpd.conf file is visible on, or copied to, all the nodes in the cluster as follows:

   chmod 600 $HOME/.mpd.conf

4. Verify that PATH settings and .mpd.conf contents can be observed through ssh on all nodes in the cluster. For example, use the following commands with each <node> in the cluster:

   ssh <node> env

   ssh <node> cat $HOME/.mpd.conf

5. Create an mpd.hosts text file that lists the nodes in the cluster, with one machine name per line, for use by mpdboot. Recall that the contents of the machines.LINUX file that was referenced previously can be used to construct an mpd.hosts file.

6. Start up the MPD daemons as follows:

   mpdboot [ -d -v ] -n <#nodes>[-f <path/name of mpd.hosts file>]

   For more information about the mpdboot command, see Setting up MPD Daemons in the <mpi-install-dir>/doc/Getting_Started.htm or the mpdboot section of <mpi-install-dir>/doc/Reference_Manual.htm.

7. Determine the status of the MPD daemons as follows:

   mpdtrace

   The output should be a list of nodes that are currently running MPD daemons.

The mpdboot Command

Use the mpdboot–f <hosts file> option to select a specific hosts file to be used. The default is to use ${PWD}/mpd.hosts. A valid host file must be accessible in order for mpdboot to succeed. As mentioned previously, you can also use the contents of the machines.LINUX file to construct an mpd.hosts file.