LSF Version 7.3 - Administering Platform LSF

Performance Tuning for Interactive Batch Jobs
594 Administering Platform LSF
Split stdout and
stderr
If in your environment there is a wrapper around bsub and LSF commands so that
end-users are unaware of LSF and LSF-specific options, you can redirect standard
output and standard error of batch interactive jobs to a file with the > operator.
By default, both standard error messages and output messages for batch interactive
jobs are written to
stdout on the submission host.
1 To write both stderr and stdout to mystdout:
bsub -I myjob 2>mystderr 1>mystdout
2 To redirect both stdout and stderr to different files, set
LSF_INTERACTIVE_STDERR=y in
lsf.conf or as an environment variable.
For example, with LSF_INTERACTIVE_STDERR set:
bsub -I myjob 2>mystderr 1>mystdout
stderr
is redirected to mystderr, and stdout to mystdout.
See the Platform LSF Configuration Reference for more details on
LSF_INTERACTIVE_STDERR.
Performance Tuning for Interactive Batch Jobs
LSF is often used on systems that support both interactive and batch users. On one
hand, users are often concerned that load sharing will overload their workstations
and slow down their interactive tasks. On the other hand, some users want to
dedicate some machines for critical batch jobs so that they have guaranteed
resources. Even if all your workload is batch jobs, you still want to reduce resource
contentions and operating system overhead to maximize the use of your resources.
Numerous parameters can be used to control your resource allocation and to avoid
undesirable contention.
Types of load conditions
Since interferences are often reflected from the load indices, LSF responds to load
changes to avoid or reduce contentions. LSF can take actions on jobs to reduce
interference before or after jobs are started. These actions are triggered by different
load conditions. Most of the conditions can be configured at both the queue level
and at the host level. Conditions defined at the queue level apply to all hosts used
by the queue, while conditions defined at the host level apply to all queues using the
host.
Scheduling
conditions
These conditions, if met, trigger the start of more jobs. The scheduling conditions
are defined in terms of load thresholds or resource requirements.
At the queue level, scheduling conditions are configured as either resource
requirements or scheduling load thresholds, as described in
lsb.queues. At the
host level, the scheduling conditions are defined as scheduling load thresholds, as
described in
lsb.hosts.
Suspending
conditions
These conditions affect running jobs. When these conditions are met, a SUSPEND
action is performed to a running job.