Understand BPPM As A Decision Maker - Part 7: Implementaion - dynamic thresholds

As mentioned previously, a dynamic threshold doesn't have an absolute value by itself.  The threshold value is calculated on the fly based on historical data values from a specified time period (also called baseline). A dynamic threshold needs to contain the following details:

1) Duration: How long does the threshold need to be violated before an alert will be raised?  By default, the duration is 0, meaning as soon as the threshold is violated an alert will be raised immediately.

2) Baseline: You can choose hously, daily, weekly, hourly & daily, and all baselines.  The default is auto baseline, meaning that BPPM server will automatically choose the best baseline for you.

3) Sampling Window: How long does a parameter/attribute value must be collected before an alert can be raised?  The default is 10 minutes or 5 data points, whichever is the longest.

4) Absolute Deviation: How much in absolute value does the parameter/attribute value must be above or below the threshold before an alert can be raised?  The default is 1.

5) Percent Deviation: How much in percentage does the parameter/attribute value must be above or below the threshold before an alert can be raised?  The default is 5%.

For example, you may want to set a dynamic threshold for your web transaction response time as follows: 1) Duration = 5 minutes; 2) Auto baseline; 3) Sampling window = 10 minutes; 4) Absolute Deviation = 1; 5) Percent Deviation = 40%.  If it normally takes 5 seconds to complete a web transaction during the same time of the day, but now it takes 7 seconds (40% more than 5 seconds) consistently for the last 5 minutes, an alert will be raised. 

As with a static threshold, a dynamic threshold can also have three different scopes: global, local, and instance.

Dynamic thresholds can only be set at BPPM server.  You can choose to use either BPPM operations console or CMA to set a dynamic threshold.  In BPPM operations console, you can use either options menu or tools menu.  In CMA, you can use global thresholds method or CMA policies.  If you use both BPPM operations console and CMA, the thresholds will be combined.  In case of conflict, the thresholds set by CMA will override the thresholds set by BPPM operations console.

In order to set a dynamic threshold in BPPM server, the parameter/attribute value must be stored in BPPM server database, meaning that the data must be streamed.  By default, all PATROL data are streamed to BPPM server database.  But you may want to filter out some data in order not to exceed 1.7 millions of attributes capacity per BPPM server.

As a decision maker, you will need to come up with detailed specification (duration, baseline, sampling window, absolute and percentage deviation) after you decide on using dynamic thresholds for some data.  You will need to decide if you need local or instance thresholds in addition to global thresholds.  You will also need to decide which method to use - BPPM operations console or CMA.