16.2 Installation and Initial Configuration

16.2.1 Basic Configuration

The configure script will set up the basic build environment and initial configuration files including the master config file, 'maui.cfg'. This master config file is a flat text file that includes information regarding resource manager interface configuration, scheduling optimizations, usage limits, and cluster usage objectives. In most cases, the initial configuration done by the configure command is adequate to allow Maui to be used immediately with no further changes. Maui is extremely configurable, with hundreds of parameters available. Rarely, however, do sites need to use more than a fraction of the available services to meet their specific needs. Maui's highly modularized design allows sites to accept the initial defaults and focus only on configuring those aspect of scheduling pertinent to their environment.

Among the parameters detected and set by the configure script are RMCFG, SCHEDCFG, and ADMIN. The initial settings of these values can be checked and modified by editing the 'maui.cfg' file. Alternatively, once the scheduler is running, Maui can be configured dynamically by using text- or GUI-based commands. For text-based configuration, the schedctl command can be used with the '-l' flag to list the value of any parameter whether explicitly set or not, while the '-m' flag can be used to dynamically modify parameter values. The online parameters documentation provides details about all Maui parameters, including format, default values, usage, examples, and links to related sections of the admin manual.

16.2.2 Simulation and Testing

Often, after the initial configuration is verified, sites choose to test the scheduler to become familiar with its capabilities and to verify basic functionality. Maui can be run in a completely safe manner by setting the MODE attribute of the SCHEDCFG parameter to TEST, that is, SCHEDCFG[orion] MODE=TEST PORT=40559. In test mode, Maui contacts the resource manager to obtain up-to-date configuration, node, and job information; however, in this mode, Maui's ability to start or modify these jobs is disabled. Once the needed parameter changes have been made, Maui can be started by issuing the command maui. At this point, commands such as showq, showstate, and checknode may be used to verify proper scheduler-resource manager communication and scheduler functionality. Details on the full suite of Maui commands are available online or in the man-page documentation included with the distribution.

16.2.3 Production Scheduling

Once evaluation is complete, the scheduler can be placed in production mode by disabling the default resource manager scheduler and setting the scheduler MODE attribute to NORMAL. Information on disabling the default resource manager scheduler is provided in the resource manager's documentation and in the online Maui migration guides located at http://supercluster.org/documentation/maui. Running in normal mode allows Maui to start, modify, and cancel jobs according to the specified scheduling policies. The default configuration of Maui enables basic scheduling services, providing first-in, first-out scheduling with backfill.