Target release Release name or number Epic Link to related JIRA epic or feature Document status Document owner Joseph Percivall Designer Lead designer Developers Lead developer QA Lead tester

Goals

• Enable Temporal Analysis using stateful processors

Background and strategic fit

The purpose of NiFi is to get the right data to the right place. Currently that is done in an effectively stateless manner by routing on the content and attributes of a single FlowFile. Now that NiFi has state for processors this opens up a whole new opportunity to leverage stateful processors to route data. An example of which is numeric anomaly detection using outliers. If a user only cares about the outliers generated by a sensor currently they have to route the data to another system to do streaming analysis before potentially routing the data back to a NiFi instance to finishing routing. With a stateful UpdateAttribute, users would be able to properly route just the outliers to their intended destination. 

This would open up many new use-cases in the IoT and Enterprise fields that currently have to be offloaded to streaming analytics platforms. 

Assumptions

• Until a more robust state provider that is designed to handle tens of thousands of requests per second is created, this will only use local state. 
• This will not be designed with the end-goal of acting as a streaming analytics platform but as another tool for the dataflow manager to route data.
  
  
• That decimals will be added to Expression Language  . Data analytics using Expression Language is very limited without the ability to work with decimals. That being said, there are a couple niche use-cases outside of data analytics that could use stateful analytics.

Requirements

#	Title	User Story	Importance	Notes
1	Add state to UpdateAttribute	Dataflow manager wants to do stateful analysis using the life of the flow.
2	Create a new RollingWindowAggregator processor	Dataflow manager wants to do stateful aggregation using a rolling window of values.

User interaction and design

Include any mockups, diagrams or visual designs relating to these requirements.

Questions

Below is a list of questions to be addressed as a result of this requirements document:

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