Trestles User Guide: Reservations
Trestles allows users to create advanced reservations for the system. These reservations guarantee the availability of nodes for a specified amount of time. Users will need to define the number of nodes, amount of time the nodes are needed, and the window of when to create the reservation.
Reservations are charged for the duration of the reservation * number of nodes * 32 (processors per node) in addition to any jobs that are submitted that make use of the reservation (unless the reservation is cancelled 24 hours before its start time).
Creating a Reservation
- Users are limited to 2 reservations, with up to 4 nodes per reservation up to 4 hours.
- The command to create a reservation is user_set_res. The format is:
For Example:$ user_set_res --account=<allocation> --nodes=<#_nodes> --duration=<time_in_seconds> --earliest_start=<time_MM/DD/YYYY> --latest_end=<time_MM/DD/YYYY> --email=<email>
creates a reservation that requests 2 nodes for 1 hour starting at earliest 10:30 on March 10, 2011 and ending at the latest 15:00 March 10,2011.$ user_set_res --account=TG-XXXXX --nodes=2 --duration=3600 --earliest_start=10:30_03/10/2011 --latest_end=15:00_03/10/2011 --firstname.lastname@example.org
Viewing your reservationYou can find your reservation number by running:
To view when your reservation will begin/end and which nodes you'll be assigned:$ show_res | grep $USER
Following our example from above:$ show_res --res=<reservation id> --readable --start --end --node_list
The reservation will begin at 10:30 on March 10, 2011 and end at 11:30. The scheduler has selected nodes trestles-1-32 and trestles-1-4.$ show_res | grep $USER 1289412186 ... (user) $ show_res --res=1289412186 --readable --start --end --node_list ... ResID StartTime EndTime NodeList 1289412186 Thu Mar 10 10:30:00 2011 Thu Mar 10 11:30:00 2011 trestles-1-32 trestles-1-4
Submitting a job to a reservationIf you want to run a job on the reservation, you'll need to modify your submit script. If you're running an interactive job, your command should be:
For a submission script:$ qsub -I -q normal -l nodes=<#_nodes>:ppn=<#_ppn>,walltime=HH:MM:SS -v Catalina_res_bind=<reservation_id>,QOS=0
If Catalina_res_bind= is not specified, the job can run in and out of the reservation. The scheduler will try to use the reserved nodes, but may use others if the reservation can't fully contain the job. Also, it's important to note that the scheduler requires a 5 minute padding for job reservations. In the example, the longest job we could request to run in the reservation would be for 55 minutes.$ cat testjob.reservation #!/bin/bash #PBS -q normal #PBS -l nodes=#NODES:ppn=#PPN #PBS -l walltime=HH:MM:SS #PBS -A <allocation> #PBS -v Catalina_res_bind=<reservation_id> cat $PBS_NODEFILE cd $PBS_O_WORKDIR
Cancel ReservationsBecause the nodes you allocate during a reservation a locked to your account, you are charged for the reservation whether you run jobs on it or not. In order to cancel a reservation:
$ user_cancel_res <reservation_id>