Oracle Activating the Moving Window Metric Baseline

Oracle Tips by Burleson Consulting

This is an excerpt from "Oracle 10g New Features for Administrators" by Ahmed Baraka.

Use the Metric Baselines page to configure your active baseline.

After baselining is activated, you can access the Metric Baselines page directly from the Database Home page by clicking the Metric Baselines link in the Related Links section.

You can either use one Moving window metric baseline or select an already defined Static baseline.

When using a Moving Window baseline, you need to select the time period you want to define for this baseline, such as "Trailing 7 days." This period moves with the current time. The most recent seven-day period becomes the baseline period (or reference time) for all metric observations and comparisons today. Tomorrow, this reference period drops the oldest day and picks up today.

Then, define the Time Grouping scheme. Grouping options available for a baseline depend on the size of the time period for the baseline. The system automatically gives you realistic choices.

After this is done, click Apply. Enterprise Manager computes statistics on all the metrics referenced by the baseline. The computing of statistics is done everyday automatically.

Setting Adaptive Alert Thresholds

Use the Edit Baseline Alert Parameters page to:

o View the current status of the 15 metrics that can be set with adaptive thresholds

o Set thresholds for Warning Level, Critical Level, and Occurrences

o Specify threshold action for insufficient statistical data

You can visualize the collected statistics for your metric baselines by following the links: Metric Baselines | click Set Adaptive Thresholds after selecting the corresponding baseline | Manage Adaptive Thresholds | click the corresponding eyeglasses icon in the Details column

Creating Static Metric Baselines

Follow the links: Manage Static Metric Baselines link in the Related Links section | Create Static Metric Baseline

On the Create Static Metric Baseline page, specify a Name for your static metric baseline. Then select a Time Period by using the Begin Day and End Day fields. These two dates define the fixed interval that calculates metric statistics for later comparisons. After this is done, select the Time Grouping scheme:

o By Hour of Day: Creates 24 hourly groups

o By Day and Night: Creates two groups: day hours (7:00 a.m. to 7:00 p.m.) and night hours (7:00 p.m. to 7:00 a.m.).

o By Day of Week: Creates seven daily groups.

o By Weekdays and Weekend: Creates two groups:
weekdays (Monday through Friday) together and weekends (Saturday and Sunday) together.

You can combine these options. For instance, grouping by Day and Night and Weekdays and Weekend produces four groups.

Then, click Compute Statistics to compute statistics on all the metrics referenced by the baseline. Enterprise Manager computes statistics only once, which is when the baseline is created.

If an alert message appears in the Model Fit column, either there is insufficient data to perform reliable calculations, or the data characteristics do not fit the metric baselines model.

If there is insufficient data to reliably use statistical alert thresholds, either extend the time period or make time groups larger to aggregate statistics across larger data samples.

Considerations

� Baselining must be enabled using Enterprise Manager.

� Only one moving window baseline can be defined.

� Multiple static baselines can be defined.

� Only one baseline can be active at a time.

� Adaptive thresholds require an active baseline.

Metric value time series can be normalized against a baseline by converting each observation to some integer measure of its statistical significance relative to the baseline.

You can see the normalized view of your metrics on the Baseline Normalized Metrics page. You access this page from the Metric Baselines page by clicking the Baseline Normalize Metrics link in the Related Links section.