Global fair share background

You can run LSF clusters in geographic sites connected by LSF multicluster capability to maximize resource utilization and throughput. Most common is to configure hierarchy fair share to ensure resource fairness among projects and users. The same fair share tree may be configured in all clusters for the same organization because users may be mobile and can log into multiple clusters. However, fair share is local to each cluster, and each user's resource usage may be fair from one cluster angle, but completely unfair from global perspective.

Figure 1 illustrates a typical multicluster environment. OrgA and OrgB are resource competitors and they both can use resources in the three clusters cluster1, cluster2, and cluster3. Under the current LSF fair share scheduling, when OrgA and OrgB compete resources in cluster1 at the same time. LSF determines which one can get the resources first only by the resource usages for OrgA and OrgB in cluster1. Their resource usage in cluster2 and cluster3 are ignored. This is fair just from cluster cluster1's perspective. But from global perspective, if OrgA is using more resources than OrgB in cluster2 and cluster3 now, it is unfair for OrgB. To improve the resource usage fairness among clusters, a new LSF feature Global fair share Scheduling is introduced. Global fair share scheduling is a new LSF job scheduling policy, under which job scheduling order of competitors is determined by resource usage among clusters.

Definitions used in this section

Global fair share scheduling

A job scheduling policy based on queue-level user-based fair share scheduling policy. Global fair share scheduling can balance users' resource usage across clusters.

Global policy daemon

The gpolicyd daemon is responsible for exchanging resource usage across clusters.

Global fair share policy

A policy that controls which queues from which cluster can exchange resource usage of share accounts with each other. It is defined in new configuration file: $LSF_ENVDIR/lsbatch/cluster_name/configdir/lsb.globalpolicies.

Global policy daemon cluster (GPD cluster)

A cluster that is configured to run gpolicyd on it.

Global fair share participating cluster

A cluster that is configured to be able to connect to gpolicyd.

Global fair share participating queue

A fair share queue in a global fair share participating cluster, and it is a participant of a global fair share policy.

Global share account

In a fair share tree of a global fair share participating queue, if a share account is configured to be able to participating the global fair share policy, it is called as a global share account.

Local share account

In a fair share tree of a global fair share participating queue, if a share account is not configured to be able to participating the global fair share policy, it is called as a local share account.