Queues are locations for jobs, are composed of compute nodes, and have rules regarding who may use them and for how long. Jobs are submitted to queues (via the qsub command) and the system decides which node or nodes assigned to the queue runs the job. Queues are aptly named; some jobs queue execute immediately (running) while others wait to execute (queued) until the requested resource(s) in the queue become available.
There are five queues: three only for jobs submitted by students and two only for the jobs submitted by staff/faculty.
|Queue||Who can use it|
|staff||faculty and staff only|
|dedicated||faculty and staff only|
There are different resources (compute nodes are one type of resource) and policies for each queue: who may use the queue, the number of jobs a user may run in a queue, how long the job may run (anther type of resource), etc. A job submitted by a student to the staff queue will be denied access and instead be routed to the student_short queue. Conversely, a job submitted by staff/faculty will not run on any of the student queues and be re-routed to the staff queue.
Regarding how long a job may execute in a queue, a job submitted to the student short queue will be terminated by the system after four hours whereas a job submitted to the staff queue has a default runtime of 72 hours. Currently when you login to argo, a chart with both the default times and maximum times is displayed. Later, you will be given commands to extract the information from the system.
The command for submitting a job on the cluster is:
qsub -V my_script
If you don't specify a queue, the system will route the job to a default queue. For a staff member, the default is the staff queue. For students, the default is student_short.
To specify a queue, you have two options. Include the queue name as an operand to the qsub command:
qsub -V -q staff my_script
or put the queue name in the script file:
#PBS -q staff
and submit the script without the queue name on the qsub line:
qsub -V my_script
qsub -V -q student_short my_script qsub -V -q student_medium my_script qsub -V -q student_long my_script qsub -V -q dedicated my_script
There is a second queue for staff (not for students); it is called dedicated. The advantage of dedicated is that you will have exclusive use of a single, dual core, dual cpu machine. Your job will be the only one running on the node assigned to the queue (unlike nodes in any other queue where your running job shares the node with other running jobs). The downside - you get it for only 30 minutes.
February 27, 2012