WLMTK Overview: Using HP-UX WLM Effectively With Your Most Critical Applications

Tools in ODBTK

This toolkit includes two tools:

• wlmoradc—This tool is a data collector for WLM and is designed to provide an easy building

block for Oracle instance management with WLM. It takes one or more SQL statements and uses

the Oracle tool SQL*Plus to connect to an Oracle instance and execute the statements, returning

either the raw value returned from SQL or the elapsed execution time. The results are sent to stdout

for human viewing, logging, or most often, for use by WLM.

• smooth—This utility, deprecated in favor of cntl_smooth starting with WLM A.02.02, takes a

stream of newline-delimited numbers and outputs a stream of numbers that are a running average of

the last n values, where n is a value that can be set on the command line. The principal use for the

smooth utility is to remove short spikes or dips in data collector output used with WLM, but it can

be applied to any stream of floating-point numbers.

Although not part of ODBTK, the functionality provided by the cpushares keyword in the WLM

configuration file fits nicely with the toolkit. The cpushares keyword is available starting with WLM

version A.01.02. The cpushares keyword enables you to request shares based on the value of a

metric, which enables you to create goal-based SLOs in WLM of the form “x CPU shares for each

metric y,” such as three CPU shares for each process in a workload.

How ODBTK works

Figure 2 illustrates how ODBTK works with your databases to get metrics to WLM. First, the toolkit

utility wlmoradc uses SQL statements to interact with the database through SQL*Plus to get the

database metrics. When wlmoradc has the resulting data, ODBTK can calculate a running average

with the smooth toolkit utility or perform no action on the data. ODBTK then sends the metrics to

WLM, which then adjusts the CPU resources for the instance’s workload so that it better meets its

SLOs. (Starting with WLM A.02.02, HP recommends the WLM configuration file-tunable

cntl_smooth over the smooth utility.)

This figure shows only a single instance, ignoring that other database instances and applications

might be on the system competing for resources.

Figure 2. How ODBTK works