Computation of Statistics Polled from Devices for Display in Widgets on Monitoring Pages
To interpret the statistical details and counters displayed in the charts and tables of the monitoring pages and in the tabular layouts, it is essential to understand the manner in which the metrics and values are retrieved from the devices and displayed in the GUI pages. In the charts, the time intervals are shown along the x-axis and data points or values of a particular attribute are shown along the y-axis. On the y-axis, the counter value displayed is the differential value between two polling intervals or the aggregated interval. For example, for the input packets of an interface, Table 1describes the mapping between polled and counter values.
Table 1: Mapping Between Polled Values and Counter Values Displayed in the GUI
Polling value from devices | 456789 | 456800 | 456825 | 456840 | 456840 |
Counter value shown on the charts and tables | – | 11 | 25 | 15 | 0 |
If the number of data points available between two intervals is more than one, the data is aggregated. The aggregation is based on the Connectivity Services Director application settings that you configure as preferences. One of the following types of statistical metrics can be viewed:
Total—Sum of the number of packets in a specific time period
Average—Average of the total number of packets in a specific time period
For example, for the input packets for an interface, the values described in Table 2 illustrate the manner in which the differential values of counters are calculated for different time periods, based on the polling intervals that are used to retrieve details from the devices.
Table 2: Computation of Counters Using Polling Intervals
Polling Time | Start | 10:30 | 10:45 | 11:00 | 11:15 | 11:30 | 11:45 |
Polling Counter Value | 525 | 550 | 555 | 575 | 590 | 625 | 640 |
Packets Per Interval | – | 25 | 5 | 20 | 15 | 35 | 15 |
Time Interval | – | 10:45 | 11:15 | 11:45 | |||
Counter Value (Average) | – | 15 | 18 | 25 | |||
Counter Value (Total) | – | 50 | 45 | 50 | |||
The number of actual data points varies between the minimum and maximum number of values, based on polling period and data availability. For the time values shown on the graph, the end time indicated is the time at which the last polling or retrieval of data occurred on the device. The interval between two data points is computed by using the total duration for which statistics is displayed by subtracting the period from the end time. The start time displayed is based on the number of intervals calculated by clocking backward from the end time.