AttributeRollingWindow

AttributeRollingWindow 2.0.0

Bundle: org.apache.nifi | nifi-stateful-analysis-nar
Description: Track a Rolling Window based on evaluating an Expression Language expression on each FlowFile and add that value to the processor's state. Each FlowFile will be emitted with the count of FlowFiles and total aggregate value of values processed in the current time window.
Tags: Attribute Expression Language, data science, rolling, state, window
Input Requirement: REQUIRED
Supports Sensitive Dynamic Properties: false

Properties

Sub-window length
When set, values will be batched into sub-windows of the set length. This allows for much larger length total windows to be set but sacrifices some precision. If this is not set (or is 0) then each value is stored in state with the timestamp of when it was received. After the length of time stated in Time window elaspes the value will be removed. If this is set, values will be batched together every X amount of time (where X is the time period set for this property) and removed all at once.

Display Name

Sub-window length

Description

When set, values will be batched into sub-windows of the set length. This allows for much larger length total windows to be set but sacrifices some precision. If this is not set (or is 0) then each value is stored in state with the timestamp of when it was received. After the length of time stated in Time window elaspes the value will be removed. If this is set, values will be batched together every X amount of time (where X is the time period set for this property) and removed all at once.

API Name

Sub-window length

Expression Language Scope

Not Supported

Sensitive

false

Required

false
Time window
The time window on which to calculate the rolling window.

Display Name

Time window

Description

The time window on which to calculate the rolling window.

API Name

Time window

Expression Language Scope

Not Supported

Sensitive

false

Required

true
Value to track
The expression on which to evaluate each FlowFile. The result of the expression will be added to the rolling window value.

Display Name

Value to track

Description

The expression on which to evaluate each FlowFile. The result of the expression will be added to the rolling window value.

API Name

Value to track

Expression Language Scope

Environment variables and FlowFile Attributes

Sensitive

false

Required

true

State Management

Scopes	Description
LOCAL	Store the values backing the rolling window. This includes storing the individual values and their time-stamps or the batches of values and their counts.

Relationships

Name	Description
set state fail	When state fails to save when processing a FlowFile, the FlowFile is routed here.
success	All FlowFiles are successfully processed are routed here
failure	When a FlowFile fails for a reason other than failing to set state it is routed here.

Writes Attributes

Name	Description
rolling_window_value	The rolling window value (sum of all the values stored).
rolling_window_count	The count of the number of FlowFiles seen in the rolling window.
rolling_window_mean	The mean of the FlowFiles seen in the rolling window.
rolling_window_variance	The variance of the FlowFiles seen in the rolling window.
rolling_window_stddev	The standard deviation (positive square root of the variance) of the FlowFiles seen in the rolling window.