Tim, The upgrade will be prevented if there are any queues that currently have flow files in them that would be removed during the upgrade.
For example, processor A is connected to B and there flow files in the queue, but in v2 A is no longer connected to B, you won't be able to upgrade until you clear the queue which can be done by stopping A first and letting it bleed out. All other changes besides this can be applied in place and everything will continue as normal. -Bryan On Mon, Mar 4, 2019 at 1:48 PM Tim Dean <[email protected]> wrote: > > I’m trying to understand what can and cannot happen to in-process flow files > during an upgrade for a versioned process group. For example, what if version > 1 of a PG has several flow files queued up waiting to be processed when I > upgrade to version 2? Will NiFi prevent me from upgrading until all flow > files have been processed? Or will it attempt to upgrade while flow files are > still in process? > > I know that the update will cause processors within the PG to be stopped and > then I presume they get restarted. If the only change in the new version are > things like processor property changes, it seems like q queued flow > files would just continue being processed. But what if connections were added > or removed? Seems like queued work could get lost or improperly routed if > NiFi attempted to handle it automatically. > > I’ve searched through various NiFi registry documents but not found any > explanation about how this kind of update problem is handled. > > Thanks > > -Tim
