17.8 Reservations in the Grid

17.8.1 Shared Resources

In some environments, globally shared resources may need to be managed to guarantee the full environment required by a particular job. Resources such as networks, storage systems, and license managers may be used only by batch workload but this workload may be distributed among multiple independent clusters. Consequently, the jobs from one cluster may utilize resources required by jobs from another. Without a method of coordinating the needs of the various cluster schedulers, resource reservations will not be respected by other clusters and will be of only limited value.

Using the centralized model, Moab allows the importing and exporting of reservations from one peer server to another. With this capability, a source peer can be set up for the shared resource to act as a clearinghouse for other Moab cluster schedulers. This source peer Moab server reports configured and available resource state and in essence possesses a global view of resource reservations for all clusters for the associated resource.

To allow the destination peer to export reservation information to the source Moab, the RMCFG lines for all client resource managers must include the flag RSVEXPORT. The source Moab should be configured with a resource manager interface to the destination peer and include both the RSVEXPORT and RSVIMPORT flags. For the destination peer, RSVEXPORT indicates that it should push information about newly created reservations to the source Moab, while the RSVIMPORT flag indicates that the source Moab server should import and locally enforce reservations detected on the destination peer server.