الملاحظات تحرير

session_count plugin

  • مقالة
  • قراءة خلال 2 دقائق

Calculates sessions count based on ID column over a timeline. The plugin is invoked with the evaluate operator.

Syntax

TabularExpression | evaluate session_count(IdColumn, TimelineColumn, Start, End, Bin, LookBackWindow [, dim1, dim2, ...])

Arguments

  • TabularExpression: The tabular expression that serves as input.
  • IdColumn: The name of the column with ID values that represents user activity.
  • TimelineColumn: The name of the column that represents the timeline.
  • Start: A scalar value that defines the start of the analysis period.
  • End: A scalar value that defines the end of the analysis period.
  • Bin: A constant scalar value that defines the session's analysis step period.
  • LookBackWindow: scalar constant value representing session lookback period. If the ID from IdColumn appears in a time window within LookBackWindow, the session is considered to be an existing one. If the ID doesn't appear, then the session is considered to be new.
  • dim1, dim2, ...: (optional) list of the dimensions columns that slice the session count calculation.

Returns

Returns a table that has the session count values for each timeline period and for each existing dimensions combination.

Output table schema is:

TimelineColumn dim1 .. dim_n count_sessions
type: as of TimelineColumn .. .. .. long

Examples

For this example, the data is deterministic, and we use a table with two columns:

  • Timeline: a running number from 1 to 10,000
  • Id: ID of the user from 1 to 50

Id appears at the specific Timeline slot if it's a divider of Timeline (Timeline % Id == 0).

An event with Id==1 will appear at any Timeline slot, an event with Id==2 at every second Timeline slot, and so on.

Here are few 20 lines of the data:

let _data = range Timeline from 1 to 10000 step 1
| extend __key = 1
| join kind=inner (range Id from 1 to 50 step 1 | extend __key=1) on __key
| where Timeline % Id == 0
| project Timeline, Id;
// Look on few lines of the data
_data
| order by Timeline asc, Id asc
| limit 20
Timeline Id
1 1
2 1
2 2
3 1
3 3
4 1
4 2
4 4
5 1
5 5
6 1
6 2
6 3
6 6
7 1
7 7
8 1
8 2
8 4
8 8

Let's define a session in next terms: session considered to be active as long as user (Id) appears at least once at a timeframe of 100 time slots, while session look-back window is 41 time slots.

The next query shows the count of active sessions according to the above definition.

let _data = range Timeline from 1 to 9999 step 1
| extend __key = 1
| join kind=inner (range Id from 1 to 50 step 1 | extend __key=1) on __key
| where Timeline % Id == 0
| project Timeline, Id;
// End of data definition
_data
| evaluate session_count(Id, Timeline, 1, 10000, 100, 41)
| render linechart

Example session count.