Aggregation types and Dynamic Baseline Aggregator
Aggregation type options
| Metric Name | Aggregation type | Description |
|---|---|---|
| Sum | The sum of alerts that are extracted. | |
| Response time | Average is the average response time taken for a specified period of time. Count is the number of alerts that are triggered based on the specified values while adding an alert. Dynamic Baseline option will automatically calculate the threshold value. Note: Metrics that have aggregators other than Average and Count, will not have the Dynamic Baseline aggregator option. For an example, see Dynamic Baseline Aggregator. | |
| Error code | Sum | Sum of alerts triggered with error codes (400-409, 429, 500-504, 511). |
| Apdex | Apdex | A ratio of requests that have been satisfied and tolerated to all requests made. |
| Instance availability | Default | The number of available instances for which alerts are triggered. |
Dynamic Baseline Aggregator
Dynamic baseline aggregator for an application metric's threshold will be set as SD*2+Mean
- Mean is the mean value of the metric value for the selected time period.
- SD is the Standard Deviation value of the mean.
- 2 is the default SD multiplier.
The default time period set is 120 minutes
An alert will be triggered if the current value of the selected metric breaches the Dynamic baseline threshold value.
Example:
If the response time of an application is 10ms, 20ms, 30ms, 40ms, 100ms for the last 10 mins then
Mean: (10+20+30+40+100)/5 =40
Standard deviation =( (10-40)2+(20-40)2+(30-40)2+(100-40)2 )/(5-1)= 1250 =√1250= 35
SD= 35.
Threshold value: (35*2)+40 = 100
Now, if the response time for current minute is greater than 100ms alert will be generated.