Plan-based scheduling and reservations
Plan-based scheduling greatly improves the original scheduling and reservation features
in LSF .
Instead of looking only at current resource availability, the scheduler can plan job placements for
the near future. Reservations are then based on these planned allocation. Plan-based scheduling is
meant to be a replacement for legacy LSF
reservation policies. When ALLOCATION_PLANNER is enabled, parameters related to
the old reservation features are ignored.
Enabling plan-based scheduling and reservations
Enabling plan-based scheduling and reservations involves the parameters ALLOCATION_PLANNER and PLAN = Y . When plan-based scheduling is enabled, parameters related to the old reservation features are ignored.
Plan-based allocation
Plan-based scheduling and reservations requires an allocation plan.
Plan-based scheduling run time
Plan-based scheduling provides an estimated run time for jobs when configured.
Plan-based scheduling limits and prioritization
Plan-based scheduling follows specific limits and prioritization rules for LSF .
Configuring extendable run limits
A job with an extendable run limit is allowed to continue running unless the resources that are occupied by the job are needed by another job in a queue with the same or higher priority.
Reserving resources for an allocation plan
In order to enact the current allocation plan, LSF uses the existing reservation mechanism to hold resources idle as needed for plans. As a general principle, LSF will try to reserve as few resources as possible in order to enact the plan.
Canceling planned allocations
In an ideal world, once a planned allocation is created it will live until the job is dispatched on the resources of the planned allocation. However, in cases where LSF detects that the planned allocation has become (or may have become) invalid, the planned allocation is canceled.
Delaying planning for jobs
In high throughput environments, it may be desirable for most jobs to use the standard LSF scheduling, without a plan. The planning based reservation can be used only to help in cases of job starvation (that is, if it is pending for longer than expected).
Limiting the number of planned jobs
When a reservation is enabled, this has the potential to decrease cluster utilization since LSF holds resources idle in order to avoid job starvation. For this reason, some sites may wish to limit the number of jobs allowed in an allocation plan.
Adjusting the plan window
The default plan-based scheduling window is 1 hour. The ALLOCATION_PLANNER parameter allows you to adjust this window.