Using and Administering

What's New in Version 2

The following is a list of new functions added for this release.

Multiple User Space Tasks per Adapter

LoadLeveler now supports running multiple user space tasks on an SP switch adapter. A job step requests adapter resources using the network statement in the job command language. See "Step 5: Specify Adapter Stanzas" and "network" for more information.

Multiple Tasks per Job per Node

The new node, tasks_per_node, and total_tasks keywords in the job command language allow you to run multiple tasks of a parallel job on the same node. See "node", "tasks_per_node" and "total_tasks" for more information.

Multiple Communication Protocols per Task

LoadLeveler now allows a job step to request the network resources required for a task to run both the Message Passing Interface (MPI) and the Low-level Application Programming Interface (LAPI) communication protocols. See "network" for more information.

National Language Support, Including New Documentation

LoadLeveler is now enabled for National Language Support (NLS). LoadLeveler error messages (from commands and APIs) are externalized both in message cataloges and the new LoadLeveler Diagnosis and Messages Guide.

Enhanced Checkpointing of Jobs

The existing support for checkpointing serial jobs has been enhanced as follows:

• LoadLeveler now continues to run the process of the job for which the checkpoint is taken, rather than terminating the process and resuming it.

• LoadLeveler now supports checkpointing C++ programs. See "Step 13: Enable Checkpointing" for more information.

• LoadLeveler now supports the checkpointing of parallel jobs when you use the new Parallel Environment (PE) parallel checkpointing API calls. See IBM Parallel Environment for AIX: Operation and Use, Volume 1 for more information.

New Scheduling Algorithm

LoadLeveler now includes an additional scheduling algorithm, the Backfill scheduler. This scheduler runs both serial and parallel jobs. However, the Backfill scheduler is primarily meant for installations running parallel jobs. See "Choosing a Scheduler" for more information.

New Command to Extract SDR Data

The new llextSDR command allows you to extract information from the system data repository (SDR) of an SP system. You can use this information in LoadLeveler administration file stanzas.

See llextSDR - Extract adapter information from the SDR for more information.

New Application Programming Interface

The new data access API allows you to retrieve specific information associated with LoadLeveler data objects.

See "Data Access API" for more information.

Command Enhancements

The llq command and the llstatus command now include options which allow you to control the output these commands produce. The new options for both commands are:

• -f, which allows you to query a list of available categories, and produces a customized version of the standard command output.

• -r, which allows you to query a list of available categories, and produces a "raw" version of the standard command output.

See llq - Query Job Status and llstatus - Query Machine Status for more information.

Graphical User Interface Enhancements

The LoadLeveler Graphical User Interface (GUI):

• Displays the new output categories available through the llq and llstatus commands.

• Contains additional resource fields which allow you to customize the headers on the Jobs and Machines windows.

• Supports the new job command language keywords.

• Includes additional selection buttons which display configured LoadLeveler features and pools.

New Job Command Language Keywords

The following are new job command language keywords.

• network

• node

• node_usage

• tasks_per_node

• total_tasks

See "Job Command File Keywords" for more information.

Administration File Changes

The following are new functions added to the administration file:

• New adapter stanza: this new stanza allows you to configure and use adapters. See "Step 5: Specify Adapter Stanzas" for more information.

• New machine stanza keywords:

  • adapter_stanzas

  • pool_list

  • spacct_excluse_enable

  • machine_mode

  See "Step 1: Specify Machine Stanzas" for more information.

• New user, group, and/or class stanza keywords:

  • max_node

  • total_tasks

  • default_interactive_class

  See "Step 2: Specify User Stanzas" for more information.

• The new llextSDR command extracts information that you can use in administration file stanzas. llextSDR - Extract adapter information from the SDR for more information.

Configuration File Changes

The SCHEDULER_TYPE keyword has been added to the configuration file. See "Step 2: Define LoadLeveler Cluster Characteristics" for more information.

New Environment Variable

The new LOADL_INTERACTIVE_CLASS environment variable allows you to set the name of the class to which an interactive parallel job is assigned. See the description of the new default_interactive_class keyword in "Step 2: Specify User Stanzas" for more information.

Resource Manager Changes

LoadLeveler now incorporates functions which were previously part of the Parallel System Support Programs (PSSP) Resource Manager. For more information, see "Resource Manager Functions Now in LoadLeveler".

Interactive Session Support Changes

The Interactive Session Support (ISS) function which was previously included with LoadLeveler is now available as part of Interactive Network Dispatcher (IND) Version 2. The ISS function in IND now allows various load measurements to be combined to form a weighted average of the overall system load. The IND product is a scaleable, load-balancing program appropriate for HTTP, FTP, and other TCP-based servers. For more information, see Interactive Network Dispatcher User's Guide, GC31-8496-02.