Submits trivial, short-lived jobs (`sleep 1`) to the queuing system via
qsub in order to keep nodes available/active in the queue. This
avoids the common delay (often 5-10 minutes) of waiting for a new node to
spin up when submitting a "real" job after a period of queue inactivity.
Jobs are submitted in bursts, repeated at a fixed interval, and the whole
process is launched in the background (fully detached using `setsid`) so
qpoke returns immediately. Each batch tops up the total number of
jobs in the queue (any job, not just `qpoke` jobs) to `n`, submitting
only as many new `qpoke` jobs as needed to reach that target.
Arguments
- n
Target total number of jobs (of any kind, not just `qpoke` jobs) to maintain in the queue. Each batch submits enough new `qpoke` jobs to bring the total queue size up to `n`. If the queue already has `n` or more jobs, no new jobs are submitted in that batch.
- dur
Total duration (in minutes) to keep poking the queue. If provided (not `NULL`), this overrides `nrep` by calculating `nrep <- dur/nsecs*60`.
- nrep
Number of times to repeat the batch of `n` submissions, with `nsecs` seconds between each batch. Ignored if `dur` is provided.
- nsecs
Number of seconds to wait between repeated batches.
Value
Nothing. Called for its side effect of submitting jobs to the queuing system via a background bash script.
Details
Only linux systems are supported. On other systems, `qpoke`
prints a message and returns invisible(NULL) without doing
anything.
Examples
if (FALSE) { # \dontrun{
## Submit 1 dummy job to wake up a node
qpoke()
## Keep one note awake for one hour. One job will be submitted every 60 seconds.
qpoke(dur=60)
## Submit 5 dummy jobs every 30 seconds, repeated 10 times
qpoke(n=5,nrep=10,nsecs=30)
## Keep poking the queue for 30 minutes, every 60 seconds
qpoke(n=5,dur=30,nsecs=60)
} # }