# Percentiles

A percentile is the value of a variable below which a certain percent of observations fall.

DX NetOps Performance Management

calculates percentiles for rollups, dashboards, and report generation purposes.HID_Percentiles

A percentile is the value of a variable below which a certain percent of observations fall. For example, the 95th percentile is the value (or score) below which 95 percent of the observations are found.

DX NetOps Performance Management

calculates percentiles for rollups, dashboards, and report generation purposes.Percentile monitoring is useful in measuring throughput data. This statistic more accurately reflects the required capacity of the monitored link for applications that are bandwidth sensitive. For example, the 95th percentile says that 95 percent of the time, the bandwidth usage is below this amount. The remaining 5 percent of the time, the bandwidth usage is above that amount.

DX NetOps Performance Management

aggregates metric values during rollups.By default,

DX NetOps Performance Management

calculates the 95th percentile for some metrics. You can include up to two configurable percentile calculations in a metric family:Metric Property | Default | Values |

Percentile | Disabled or 95 | 0 or 95 |

Percentile2 | Disabled | 0-99 |

Percentile3 | Disabled | 0-99 |

A value of 0 disables the percentile calculation.

For more information about how to edit metrics, see Edit a Metric.

Changes to these properties (percentile calculations) generate administration events. After you update the metric family, the percentile data is available for reporting within several poll cycles. For trend views, changes cause a gap in the trend line. For table views, changes affect the value of the percentile for time ranges when the change occurred. For example, in a daily time range, the value is inaccurate for one day.

For more information about administration events, see Event Types.

If you disable a percentile calculation, avoid errors in views that include the percentile by modifying them.

Calculate only the percentiles that you need. Each percentile that you calculate can significantly affect system performance.

Three percentile values appear in the

**table for a data source. A dash in the**Metric Families

**column of the**Percentiles

**tab indicates that all three percentile values are equal to zero.**Metrics

For more information about how to view this table, see Manage Metric Families.

Percentile Calculations

Percentile calculations use the Microsoft Excel method. Hourly and daily rollup performs the percentile calculation on the polled rate data. Weekly rollup performs the percentile calculation on the results of the daily rollups.

DX NetOps Performance Management

calculates percentiles and exposes them to the reports and dashboards.