Link Sessions

Altair Analytics Workbench can use Hub to launch remote Altair SLC sessions. Rather than Altair Analytics Workbench having to make an explicit SSH connection to a particular host to launch an Altair SLC session on that host, it makes a request to the Altair SLC Hub for it to launch a link session. The Altair SLC Hub schedules the Altair SLC session to be run on a suitable node within the Altair SLC Hub cluster.

Execution Profiles and Launch Configurations

Altair SLC Hub has a concept of an execution profile that governs various aspects of how a workload is run, such as selecting a version of Altair SLC, defining startup environment variables, or constraints over where the workload is run in the cluster. For more information see Execution Profiles.

Within the Altair Analytics Workbench, a user can define one or more servers each of which represents an Altair SLC processing engine. Multiple servers can be defined, either for the purposes of having Altair SLC with different startup options, different versions of Altair SLC, or to enable multiple sessions and so multiple programs, to be run at once.

When configuring a server in Altair Analytics Workbench, part of the setup is the Launch Configuration. The launch configurations presented in Altair Analytics Workbench are provided by Altair SLC Hub from querying the defined execution profiles and returning those execution profiles that the user has permission to access.

Altair SLC Hub execution profiles enable the user to select from a list of administrator-defined configurations governing various aspects such as the version of Altair SLC used, where the Altair SLC session is run, the startup system options applied to the processing engine, the environment variables that are set and so on.

Setting System Options

The environment and options of a link session are controlled by the execution profile that it is run under. The execution profiles allow setting environment variables, this can be useful to add database drivers to the lookup PATH or to set Altair SLC system options.

Do not specify Altair SLC system options using the WPS_OPTIONS environment variable. This environment variable is reserved for use in Altair SLC to set Hub connection details.

To pass Altair SLC system options to a worker node, specify options as they would appear on a command line to the WPSV5_OPTIONS environment variable. For example, the following changes the encoding used by the SLC processing engine, and prevents the processing engine from accessing library definitions:

-ENCODING UTF-8 -NOHUB_AUTOLIBS