Thanks Bryan - Are there any other considerations that are used to determine if an upgrade should be prevented? Or is it strictly a matter of making sure that any queued flow files are in queues that will continue to exist after upgrade. I assume, for example, that there is no way to prevent upgrades if the schema of a flow file changes incompatibly from one version to the next?
What I’m really trying to understand is the rules/guidelines I need to follow in my flow designs to make sure that upgrading from one version to another will not result in loss of data. Thanks -Tim > On Mar 4, 2019, at 1:18 PM, Bryan Bende <[email protected]> wrote: > > 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
