Administering Platform LSF - SAS

Chapter 6
Managing Jobs
Pending jobs
Viewing pending
reasons
Suspended jobs
A job remains pending until all conditions for its execution are met. Some of
the conditions are:
◆ Start time specified by the user when the job is submitted
◆ Load conditions on qualified hosts
◆ Dispatch windows during which the queue can dispatch and qualified
hosts can accept jobs
◆ Run windows during which jobs from the queue can run
◆ Limits on the number of job slots configured for a queue, a host, or a user
◆ Relative priority to other users and jobs
◆ Availability of the specified resources
◆ Job dependency and pre-execution conditions
Use the bjobs -p command to display the reason why a job is pending.
A job can be suspended at any time. A job can be suspended by its owner, by
the LSF administrator, by the root user (superuser), or by LSF.
After a job has been dispatched and started on a host, it can be suspended by
LSF. When a job is running, LSF periodically checks the load level on the
execution host. If any load index is beyond either its per-host or its per-queue
suspending conditions, the lowest priority batch job on that host is suspended.
If the load on the execution host or hosts becomes too high, batch jobs could
be interfering among themselves or could be interfering with interactive jobs.
In either case, some jobs should be suspended to maximize host performance
or to guarantee interactive response time.
LSF suspends jobs according to the priority of the job’s queue. When a host is
busy, LSF suspends lower priority jobs first unless the scheduling policy
associated with the job dictates otherwise.
Jobs are also suspended by the system if the job queue has a run window and
the current time goes outside the run window.
A system-suspended job can later be resumed by LSF if the load condition on
the execution hosts falls low enough or when the closed run window of the
queue opens again.
Viewing suspension reasons
Use the bjobs -s command to display the reason why a job was suspended.
WAIT state (chunk jobs)
If you have configured chunk job queues, members of a chunk job that are
waiting to run are displayed as WAIT by bjobs. Any jobs in WAIT status are
included in the count of pending jobs by bqueues and busers, even though
the entire chunk job has been dispatched and occupies a job slot. The bhosts
command shows the single job slot occupied by the entire chunk job in the
number of jobs shown in the NJOBS column.
Administering Platform LSF 113