Mark made a lot of improvements to this back in 1.12.0 [1].

I think you don't need to delete flow.xml.gz anymore, it will just
take what the cluster has, as long as it doesn't require removing
connections with data, and it backs up the current flow to a back up
directory.

[1] https://issues.apache.org/jira/browse/NIFI-6849

On Thu, Aug 26, 2021 at 11:33 AM Joe Witt <joe.w...@gmail.com> wrote:
>
> Shawn
>
> Ok cool.  I think we'll go that route.  A lot less code.  A lot easier
> to reason over.  We tried to be clever and it kept backfiring.
> Simpler wins.
>
> Thanks
>
> On Thu, Aug 26, 2021 at 8:28 AM Shawn Weeks <swe...@weeksconsulting.us> wrote:
> >
> > As long as we have a check to make sure no data is in flow on the node 
> > joining that sounds wonderful and a lot simpler. In my most recent case I 
> > just stopped the inputs and waited till everything cleared and then 
> > shutdown and delete flow.xml.gz and restarted. That's already worlds easier 
> > than how it used to be.
> >
> > Thanks
> > Shawn
> >
> > -----Original Message-----
> > From: Joe Witt <joe.w...@gmail.com>
> > Sent: Thursday, August 26, 2021 10:23 AM
> > To: users@nifi.apache.org
> > Subject: Re: Make NiFi Flow Read Only on Disconnect
> >
> > Shawn
> >
> > So that is one direction (being more restrictive).  Another direction is to 
> > simply ditch the logic we have and allow changes and simply update the 
> > disconnected node when it rejoins.  We have all kinds of super complex 
> > super duper awesome logic in there to help prevent users from getting into 
> > a bad state.  What we have found is it was a lot of effort with minimal 
> > payoff.  The simpler model is simply 'add the node to the cluster, make 
> > changes to ensure the flow matches, and move on'.
> > The only failure case would be when connecting and there is data in a 
> > connection which no longer exists.  We can make exception handling for that 
> > mode.
> >
> > How does that sound for you?
> >
> > Thanks
> >
> > On Thu, Aug 26, 2021 at 7:51 AM Shawn Weeks <swe...@weeksconsulting.us> 
> > wrote:
> > >
> > > Hi, I know there have been a lot of improvements handling flow.xml.gz 
> > > differences between nodes if a node get’s disconnected or is down. I was 
> > > wondering if there is a way to prevent NiFi from allowing any flow 
> > > changes if all nodes are not up and available, both on the node that’s in 
> > > a “DISCONNECTED” state and for the remaining cluster nodes. I’m trying to 
> > > prevent the scenarios where a node ends up a disconnected state but still 
> > > allows changes making reconnections more challenging.
> > >
> > >
> > >
> > > Thanks
> > >
> > > Shawn

Reply via email to