Reservations, extensions, and on-demand experiments coexistence
Experiment extensions push resource allocations forward, sometimes clashing with unapproved reservations, which seek to carve out specific future time slots for resource use. Extensions are currently granted, with automatic approval, for existing experiments for up to 1 week from the initial start of the experiment (up to an additional week can be requested later, for a total of 2 weeks of auto-approved extension). Some reservations are automatically granted and some are auto-approved, depending on the resources and time period requested. Reservations for resources that require admin approval may be submitted with a start time as soon as 9 AM the next business day. If a reservation requiring admin approval is posted in the period between reviews (longer on weekends), a subsequent automatically-approved extension involving those same resources can cause this reservation request to no longer be viable. The resulting resource contention usually results in the reservation request being denied, with a note explaining the situation and requesting that the user make a new request. This is a fairly frequent problem, especially for reservations starting on Monday mornings with a weekend in between admin reviews.
On POWDER, where admin-approved reservations are required for some resources, this extension-reservation clash is often confusing and frustrating for users. To try and ease this tension, we came to a consensus in a recent team meeting to make the following policy (and associated enforcement) changes:
- Increase the minimum start time for new reservation requests requiring admin approval to 2 business days.
- Starting no earlier than 9 AM on the second business day.
- Decrease the maximum auto-approved extension request duration to 24 hours from the current time.
- Additional auto-approved extensions can be granted for up to 24 hours from the current time over 2 weeks.
- Longer extensions can still be requested, but will require admin approval.
Taken together these changes will force auto-approved extensions to stay clear of pending reservation requests. I will write up an announcement to send to users to explain the changes in reservation and extensions policy. I'm only suggesting this change for POWDER, but of course it could be applied elsewhere.