Web Planner Traffic Aggregation

Performance Data Indices Used for Aggregated Queries

The analytics database stores performance data in a series of indices. The default index for a measurement contains each measurement to a granularity of five minutes. High frequency measurements collected through Telemetry are stored in a special index used mostly for real-time traffic graphs. The high-speed (raw) index is then recorded as an average into the default index. The default index has a configurable retention period.

The measurements are then rolled up hourly with average and 90 percentile aggregations, and this rolled-up index is used for more scalable queries on the performance data. In addition to the hourly index, the default index is also rolled up into daily, weekly and monthly indices to support queries over longer time frames. .

The performance data indices are summarized in Table 1.

Generate Options

Remember that performing the appropriate data collection tasks in the NorthStar Controller is a prerequisite to performing traffic aggregation.

The generate options are:

• Interface Traffic

• Interface CoS Traffic

• Tunnel Traffic

• Demand and Traffic Loads

Click the check boxes to select as many of these options as you want, except that Interface Traffic and Interface CoS Traffic are mutually exclusive. They use the same interface traffic files for output, so you can only have one or the other.

Range Options

Click any one of the radio buttons to select that range. For Start Date and End Date, click in each of those fields to bring up the calendar or calendar/clock window. The Start Date and End Date formats are a little different, depending on what you choose for Series:

• If Series = “Hour of day aggregation” or “Time Series”, the Start Date and End Date are specified as just the date because all hours of the specified days are used. A calendar window displays for you to select the date.

• If Series = “Time Series - Hourly”, the Start Date and End Date are specified as date and hour. In this case, a calendar/clock window displays, with calendar and clock icons for selecting the date and the hour, respectively. Note that it is a 24-hour clock as shown in Figure 2.

  Figure 2: Calendar and Clock Icons in the Calendar/Clock Window

Series Options

Three options are available for Series:

• Hour of day aggregation

  In this type of series, all measurements are aggregated by hour of day, potentially across multiple days. For example, by specifying “last week”, you would get the average or 90 percentile traffic for 9 – 10 PM. All measurements between 9 and 10 PM from all seven days would be considered in the calculation of the statistics. This is useful for calculating a typical day across a date range. Each parameter would have 24 values in the resultant traffic file, corresponding to each hour in the typical day. The usefulness of this series type diminishes as the time range becomes longer because the impacts of traffic trend over the time range would skew the statistic to represent either the time range mid-point or end-point for average and 90 percentile statistics, respectively.

• Time Series

  When you select Time Series, an additional Interval field is displayed. One data point per the specified interval (1 day, 1 week, or 1 month) between the selected start and end dates is used. How you set your range and interval will determine the number of data points. For example, if you do daily statistic calculations for 24 days, you would have 168 data points. If you were interested in a time series for four months of data, you might want to use a courser interval such as weekly.

• Time Series - Hourly

  Time Series – Hourly is a variation of Time Series that specifically uses one hour as the interval. One data point per hour is used, for the duration of the date range you specify.

Statistic Options

Use the drop-down menu to select from the two traffic statistics options offered. The two options enable different objectives in modeling:

• Average: Provides a representation of the typical traffic during a period.

• 90 percentile: Provides a representation of peak traffic during a period.

For recent time ranges (last day or week), there might not be a large difference in these values for hourly interval time series or hour of day aggregation. For daily or larger intervals, 90 percentile might be a better choice for capacity planning.

Output Directory and Output Runcode

The output directory is /opt/northstar/data/network_archive .

The output runcode defaults to the current model’s runcode.

Load New Data

If you select “Load new data” in the Traffic Aggregation window, the extracted performance files are read into the current model and displayed in the network information table in columns that are only shown once traffic aggregation data is available. In the Tunnel and Demand tabs, the results are displayed in the Traffic column. In the Interface tab, the results are displayed in the Ingress Traffic and Egress Traffic columns. Figure 3, Figure 4, and Figure 5 show examples.

Figure 3: Tunnel Tab Showing Traffic Column

Figure 4: Interface Tab Showing Ingress and Egress Traffic Columns

Figure 5: Demand Tab Showing Traffic Column