LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 661
Tuning the Cluster
LIM uses load thresholds to determine whether to place remote jobs on a host. If
one or more LSF load indices exceeds the corresponding threshold (too many users,
not enough swap space, etc.), then the host is regarded as busy and LIM will not
recommend jobs to that host.
Thresholds can be set for any load index supported internally by the LIM, and for
any external load index.
If a particular load index is not specified, LIM assumes that there is no threshold for
that load index. Define looser values for load thresholds if you want to aggressively
run jobs on a host.
See Load Thresholds on page 553 for more details.
In this section ◆ Load indices that affect LIM performance on page 661
◆ Comparing LIM load thresholds on page 661
◆ If LIM often reports a host as busy on page 662
◆ If interactive jobs slow down response on page 662
◆ Multiprocessor systems on page 662
Load indices that affect LIM performance
For more details on load indices see Load Indices on page 239.
Comparing LIM load thresholds
To tune LIM load thresholds, compare the output of lsload to the thresholds
reported by
lshosts -l.
The
lsload and lsmon commands display an asterisk * next to each load index that
exceeds its threshold.
Example
Consider the following output from
lshosts -l and lsload:
lshosts -l
HOST_NAME: hostD
...
LOAD_THRESHOLDS:
r15s r1m r15m ut pg io ls it tmp swp mem
- 3.5 - - 15 - - - - 2M 1M
HOST_NAME: hostA
...
Load index Description
r15s 15-second CPU run queue length
r1m 1-minute CPU run queue length
r15m 15-minute CPU run queue length
pg Paging rate in pages per second
swp Available swap space
it Interactive idle time
ls Number of users logged in