I think this is non-abstract enough, if you need more detail we can talk
offline. The use case is that I have two operators Operators A and B.
Operator A processes data according to a schema and emits tuples
corresponding to that schema which is tagged with a schema ID. Operator B
receives the processed data checks the schema ID and looks up the
appropriate meta information to continue processing the tuples. If I want
to make a change to the schema that is used to process the tuples while the
application is running I need to set a property which updates the schema
for both Operators A and B. If the schema is updated for Operator A before
it is updated for Operator B, that is bad because then Operator B will be
receiving data it doesn't understand yet. If the schema is updated on
Operator B and then Operator A that is okay, but it requires the user to be
careful about monitoring their properties and introduces the possibility of
user error.

Thanks,
Tim

On Mon, Sep 21, 2015 at 9:35 AM, Chetan Narsude <[email protected]>
wrote:

> Tim, can you share the specific (non-abstract) use case if appropriate
> publicly? Or PM me.
>
> --
> Chetan
>
> On Mon, Sep 21, 2015 at 10:30 AM, David Yan <[email protected]> wrote:
>
> > Currently setting of operator properties are done by issuing
> > StramToNodeRequests, which means that it will only be handled at window
> > boundaries (specifically at END_WINDOW) upon receipt of the heartbeat
> > response from STRAM.
> >
> > I agree with Amol.  Your requirement will need such operations to be
> > injected in a control tuple.
> >
> > David
> >
> > On Sun, Sep 20, 2015 at 12:30 AM, Amol Kekre <[email protected]>
> wrote:
> >
> > > Tim,
> > > We will need to add a new control tuple. The only way to set properties
> > on
> > > two operators at the begining of the same window is via a control
> tuple.
> > > Other way may be that Stram sends information to StramChild with a
> window
> > > ID way in the future. Second approach is not good, and theoratically
> does
> > > not guarantee the alignment anyway.
> > >
> > > Thks,
> > > Amol
> > >
> > >
> > > On Sat, Sep 19, 2015 at 2:58 PM, Timothy Farkas <[email protected]>
> > > wrote:
> > >
> > > > Hello all,
> > > >
> > > > If I dynamically set a property on an operator, does the value of
> that
> > > > property get updated between windows or could it get updated in the
> > > middle
> > > > of a window? Also is it possible to set multiple properties on
> > operators
> > > > simultaneously?
> > > >
> > > > For example let's say I have Operator A with Property 1 and Operator
> B
> > > with
> > > > Property 2. If I want to set both Properties 1 and 2 on Operators A
> > and B
> > > > right before window N in both operators, is there a mechanism by
> which
> > I
> > > > can do that?
> > > >
> > > > I think this could be accomplished by creating a separate update
> > operator
> > > > on which properties are set, and which emits the updates to
> downstream
> > > > operators to be updated, but I am wondering if there is a better
> > > solution.
> > > >
> > > > Thanks,
> > > > Tim
> > > >
> > >
> >
>

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