HP-UX Workload Manager User's Guide

Advanced WLM usage: Using performance metrics
Supplying data to WLM
Appendix H 501
For information on signal handling, see “Handling signals in data
collectors” on page 515.
Run your data collection program in the group PRM_SYS to ensure it
receives the proper resources.
Each data collector should send data to WLM once per WLM interval, if
possible. (For information on this interval, see “Specifying the WLM
interval (optional)” on page 215.) If the data collector sends data to WLM
less than once per interval (meaning an entire interval passes with no
new data), the associated controller requests the same allocation as it did
for the previous interval. When your data collector sends data more than
once per interval, WLM only receives the last data sent before the
interval ended. All the other data sent during the interval is lost. In this
case, your data should reflect performance over a period of time rather
than at a single point in time.
NOTE WLM runs data collectors with UID set to root. If a data collector that
uses the WLM API changes its UID, all subsequent calls to the WLM API
will fail.
NOTE If a data collector exits unexpectedly, restart it by re-activating the
configuration:
# wlmd -a configfile
Re-activating the configuration resets all resource allocations, causing
WLM to reconverge on the allocations needed to meet the configuration’s
SLOs.
The API functions are described in the following sections.
Opening communications with wlm_mon_attach() The data
collector uses the wlm_mon_attach() function to open a connection to the
WLM daemon to send performance data to the daemon.
To use this function, you must reference the following include file:
/opt/wlm/include/wlm.h