NIFI processor state

[#1]

I'm just curious to know. When I start a processor in the NIFI cluster, where does NIFI store the processor state "RUNNING" in this case?

[#2 · Accepted solution]

@edim2525 

The entire datflow(s) reside in NiFi heap memory and are persisted to disk in the flow.json.gz file.  This includes the current set state for each component.  Every time a change is made to the NiFi canvas, the current persisted flow.json.gz is moved to archive and a new flow.json.gz is written.

When NiFi is started it will load the flow.json.gz in to NiFi heap memory and set the state to the state for each component recorded in the the flow.json.gz that is loaded.  Only time this is not true is when the nifi.properties property "nifi.flowcontroller.autoResumeState" has been set to false.  When set to false, all "RUNNING" components set in the flow.josn.gz will load into heap as "STOPPED".    NiFi will then archive the current flow.json.gz and write a new flow.json.gz with those new "STOPPED" states.

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Thank you,
Matt

[#3]

Thank you for the detailed explanation, Matt