HP-MPI Version 2.3.1 for Linux Release Note

3.6 Redundant License Servers
This release supports redundant license servers using the FLEXnet Publisher licensing
software. Three servers can create a redundant license server network. For a license
checkout request to be granted, at least two servers must be running and able to
communicate with each other. This avoids a single-license server failure which would
prevent new HP-MPI jobs from starting. With three-server redundant licensing, the
full number of HP-MPI licenses can be used by a single job.
When selecting redundant license servers, use stable nodes that are not rebooted or
shutdown frequently. The redundant license servers exchange heartbeats. Disruptions
to that communication can cause the license servers to stop serving licenses.
The redundant license servers must be on the same subnet as the HP-MPI compute
nodes. They do not have to be running the same version of operating system as the
HP-MPI compute nodes, but it is recommended.
Each server in the redundant network must be listed in the HP-MPI license key by
hostname and hostid. The hostid is the MAC address of the eth0 network interface.
The eth0 MAC address is used even if that network interface is not configured. The
hostid can be obtained by typing the following command if HP-MPI is installed on the
system:
% /opt/hpmpi/bin/licensing/arch/lmutil lmhostid
The eth0 MAC address can be found using the following command:
% /sbin/ifconfig | egrep "^eth0" | awk '{print $5}' | sed s/://g
The hostname can be obtained by entering the command hostname.
To request a three server redundant license key for HP-MPI V2.3 for Linux, contact the
HP licensing center. For more information, see your license certificate.
3.7 License Release/Regain on Suspend/Resume
HP-MPI now supports the release and regain of license keys when a job is suspended
and resumed by a job scheduler. This feature is recommended for use only with a batch
job scheduler. To enable this feature, add HPMPI_ALLOW_LICENSE_RELEASE=1 to
the mpirun command line. When mpirun receives a SIGTSTP, the licenses that are
used for that job are released back to the license server. Those released licenses can run
another HP-MPI job while the first job remains suspended. When a suspended mpirun
job receives a SIGCONT, the licenses are reacquired and the job continues. If the licenses
cannot be reacquired from the license server, the job exits.
When a job is suspended in Linux, any memory that is pinned is not swapped to disk,
and is not handled by the operating system virtual memory subsystem. HP-MPI pins
memory that is associated with RDMA message transfers. By default, up to 20% of the
system memory can be pinned by HP-MPI at any one time. The amount of memory
that is pinned can be changed by two environment variables: MPI_PHYSICAL_MEMORY
and MPI_PIN_PERCENTAGE (default 20%). The -dd option to mpirun displays the
16 New or Changed Features in V2.3