Using and Administering

network

Specifies communication protocols, adapters, and their characteristics. You need to specify this keyword when you want a task of a parallel job step to request a specific adapter that is defined in the LoadLeveler administration file. You do not need to specify this keyword when you want a task to access a shared, default adapter via TCP/IP. (A default adapter is an adapter whose name matches a machine stanza name.)

Note that you cannot specify both the network statement and the Adapter requirement (or the Adapter preference) in a job command file. Also, the value of the network keyword applies only to the job step in which you specify the keyword. (That is, this keyword in not inherited by other job steps.)

The syntax is:

network.protocol = network_type [, [usage] [, mode [, comm_level] ] ]

Where:

protocol

Specifies the communication protocol(s) that are used with an adapter, and can be the following:

MPI

Specifies the Message Passing Interface. You can specify in a job step both network.MPI and network.LAPI.

LAPI

Specifies the Low-level Application Programming Interface. You can specify in a job step both network.MPI and network.LAPI.

PVM

Specifies a Parallel Virtual Machine job. When you specify in a job step network.PVM, you cannot specify any other network statements in that job step. Also, the adapter mode must be IP.

network_type

Specifies either an adapter name or a network type.This field is required. The possible values for adapter name are the names associated with the interface cards installed on a node (for example, en0, tk1, and css0). The possible values for network type are installation-defined; the LoadLeveler administrator must specify them in the adapter stanza of the LoadLeveler administration file using the network_type keyword. For example, an installation can define a network type of "switch" to identify css0 adapters. When a switch adapter exists on a node, the network_type can be specified as csss, which indicates that the fastest switch communication path should be used. For more information, see Step 5: Specify Adapter Stanzas.

usage

Specifies whether the adapter can be shared with tasks of other job steps. Possible values are shared, which is the default, or not_shared.

mode