Network Queuing System(NQS)

Network Queuing System(NQS)

• Controls batch queues

• Only on Cray SV1

• Presently 8 queues available for general use and one queue for the Cray analyst.

• Queue sizes range from 16MW-512MW and 144000 - 324000 CPU seconds. On Cray systems 8 bytes = 1 word

Accessing NQS

• Log on to the Cray SV1 thru telnet or rlogin

• Use the rsh command at a UNIX workstation

NQS allows the user to.......

• Execute jobs in batch mode• Continue to use the terminal/workstation

while batch jobs execute• Execute jobs whether or not interactive

session remains active• Specify job limits• Monitor an NQS job’s progress• Allows checkpointing and restarts

Submitting Jobs to NQS• The qsub command submits jobs to the NQS system

for batch execution. qsub can take input from the terminal or from a file.

This would submit a job to the default queue:cray% qsub cd f90 myfile.f ./a.out > my.out CTRL/D

• Resource limits can be defined either on the qsub command line or within the script file that is submitted to NQS. These limits are then used by NQS to determine which batch queue will be used for your job.

• For example the per-request CPU limit can be set either by:

qsub -lT 1000 batchfile

or from within the script “batchfile” by:

# QSUB -lT 1000

Checking Job Status

• The qstat command can be used to display the status of requests in NQS queues and the current state of NQS queues.

qstat -a <shows status of requests>

qstat -b <shows state of queues>

• The qdel command can be used to cancel a queued job or to send a signal that kills an executing job.

qdel 9678 <deletes queued job 9678>

qdel -9 9678 <deletes running job 9678>