Administering Platform LSF - SAS

Chapter 32
Interactive Jobs with bsub
Types of load indices
Paging rate (pg)
Interactive idle
time (it)
To effectively reduce interference between jobs, correct load indices should be
used properly. Below are examples of a few frequently used parameters.
The paging rate (pg) load index relates strongly to the perceived interactive
performance. If a host is paging applications to disk, the user interface feels
very slow.
The paging rate is also a reflection of a shortage of physical memory. When an
application is being paged in and out frequently, the system is spending a lot
of time performing overhead, resulting in reduced performance.
The paging rate load index can be used as a threshold to either stop sending
more jobs to the host, or to suspend an already running batch job to give
priority to interactive users.
This parameter can be used in different configuration files to achieve different
purposes. By defining paging rate threshold in lsf.cluster.cluster_name,
the host will become busy from LIM’s point of view; therefore, no more jobs
will be advised by LIM to run on this host.
By including paging rate in queue or host scheduling conditions, jobs can be
prevented from starting on machines with a heavy paging rate, or can be
suspended or even killed if they are interfering with the interactive user on the
console.
A job suspended due to pg threshold will not be resumed even if the resume
conditions are met unless the machine is interactively idle for more than
PG_SUSP_IT seconds.
Strict control can be achieved using the idle time (it) index. This index
measures the number of minutes since any interactive terminal activity.
Interactive terminals include hard wired ttys, rlogin and lslogin sessions,
and X shell windows such as xterm. On some hosts, LIM also detects mouse
and keyboard activity.
This index is typically used to prevent batch jobs from interfering with
interactive activities. By defining the suspending condition in the queue as
it50, a job from this queue will be suspended if the machine is not
interactively idle and the paging rate is higher than 50 pages per second.
Furthermore, by defining the resuming condition as it>5 && pg