@Soli  Unfortunately, there is not enough shared to say what is taking so long during your startup.  Above log snippet shows ~.001 millisecond between each log line.  At 34,000 connections, that would be only 34 seconds.  Assuming About the same for other components, I don't think the synchronizing of components is what is taking the bulk of the 10-15 minutes of startup time.  In the nifi-app.log, what time is reported application start: INFO [main] org.apache.nifi.runtime.Application Started Application in <xxxxx> seconds What does each node report here?  Are all nodes taking roughly same time to start or is there any specific node taking longer then the other two? Is performance good once NiFi is up and running? Are all ~21,000 components in the running state? Any WARN or ERROR logging during startup? How many FlowFiles are queued per node? After NiFi is started, maybe collect a verbose NiFi diagnostics output for review. ./bin/nifi.sh diagnostics --verbose diag.txt You may also collect thread dumps  every minute during startup to see what thread during is taking so long. Hopefully some of this will help you see what is slowing your startup. There have been some improvements to startup time in Apache NiFi 2.x release. There were a few improvements to startup in Nifi 1.x releases, but those were made prior to 1.22.   Please help our community grow. If you found any of the suggestions/solutions provided helped you with solving your issue or answering your question, please take a moment to login and click "Accept as Solution" on one or more of them that helped. Thank you, Matt ... View more

Hi, @TimothySpann  Yes, our final upgrade version is 1.22.0 and there is not  ghosted processors. We want to know the  basic principle of ListFile+Redis cache mapping. We found file state had some change that stored in "redis". The change is reflected in the precision of the file's modify time. ps. We upgrade nifi on the same machine, time is still the same.  1.9.2 {'/mnt/EDA_DATA/NIFI/cloud/upgrade_test/ControlRate5/04594': {'timestamp': 1701853172000, 'size': 0}, '/mnt/EDA_DATA/NIFI/cloud/upgrade_test/ControlRate5/04593': {'timestamp': 1701853171000, 'size': 0}} 1.22.0 {'/mnt/EDA_DATA/NIFI/cloud/upgrade_test/ControlRate5/04594': {'timestamp': 1701853172307, 'size': 0}, '/mnt/EDA_DATA/NIFI/cloud/upgrade_test/ControlRate5/04593': {'timestamp': 1701853171506, 'size': 0}}   ... View more

 > ListFile will lose tracking. This is beyond my knowledge. According to the introduction of ListFile, the tracking entity will be stored in redis. Why is it lost when I only upgrade nifi? ... View more