Let me preface this by saying I have opened a support case on this question. I notices last week that a new upgrade for NTA is available. I currently have NTA 4.0 and am using the new NTA flow server. In the past when we upgraded NTA we installed the upgrade on the NPM main server, the additional pollers, and the additional web server. Now there is a new server in the mix, the NTA flow server. Neither the FAQ document or any of the documents in the 4.0.2 upgrade address if this install needs to be on the NTA flow server too.
I'd appreciate of any of the Solarwinds NTA team would speak up quickly on this question.