questions regarding stateful functions

[Marco Villalobos-2]

Upon reading about stateful functions, it seems as though first, a data stream has to flow to an event ingress.  Then, the stateful functions will perform computations via whatever functionality it provides. Finally, the results of said computations will flow to the event egress which will be yet another datastream within the data stream job.

Is my understanding correct?

I was hoping that a stateful function could be called by a process function, is that possible? (I am guessing no).

Please let me know. 

Thank you.  Sincerely,

Marco A. Villalobos

[Igal Shilman]

Hello Marco!

Your understanding is correct, but in addition

You can also use StateFun within a DataStream application [1]

[1] https://ci.apache.org/projects/flink/flink-statefun-docs-master/docs/sdk/flink-datastream/

On Wed, Apr 7, 2021 at 2:49 AM Marco Villalobos <[hidden email]> wrote:

Upon reading about stateful functions, it seems as though first, a data stream has to flow to an event ingress.  Then, the stateful functions will perform computations via whatever functionality it provides. Finally, the results of said computations will flow to the event egress which will be yet another datastream within the data stream job.

Is my understanding correct?

I was hoping that a stateful function could be called by a process function, is that possible? (I am guessing no).

Please let me know. 

Thank you.  Sincerely,

Marco A. Villalobos

[Marco Villalobos-2]

Thank you for the clarification. 

BUT....there was one question not addressed:

Can a stateful function be called by a process function?

On Wed, Apr 7, 2021 at 8:19 AM Igal Shilman <[hidden email]> wrote:

Hello Marco!

Your understanding is correct, but in addition

You can also use StateFun within a DataStream application [1]

[1] https://ci.apache.org/projects/flink/flink-statefun-docs-master/docs/sdk/flink-datastream/

On Wed, Apr 7, 2021 at 2:49 AM Marco Villalobos <[hidden email]> wrote:

Upon reading about stateful functions, it seems as though first, a data stream has to flow to an event ingress.  Then, the stateful functions will perform computations via whatever functionality it provides. Finally, the results of said computations will flow to the event egress which will be yet another datastream within the data stream job.

Is my understanding correct?

I was hoping that a stateful function could be called by a process function, is that possible? (I am guessing no).

Please let me know. 

Thank you.  Sincerely,

Marco A. Villalobos

[Igal Shilman]

Yes it is possible. A process function upstream to a stateful function can emit a message that

in turn will be routed to that function using the data stream integration.

On Wed, Apr 7, 2021 at 7:16 PM Marco Villalobos <[hidden email]> wrote:

Thank you for the clarification. 

BUT....there was one question not addressed:

Can a stateful function be called by a process function?

On Wed, Apr 7, 2021 at 8:19 AM Igal Shilman <[hidden email]> wrote:

Hello Marco!

Your understanding is correct, but in addition

You can also use StateFun within a DataStream application [1]

[1] https://ci.apache.org/projects/flink/flink-statefun-docs-master/docs/sdk/flink-datastream/

On Wed, Apr 7, 2021 at 2:49 AM Marco Villalobos <[hidden email]> wrote:

Upon reading about stateful functions, it seems as though first, a data stream has to flow to an event ingress.  Then, the stateful functions will perform computations via whatever functionality it provides. Finally, the results of said computations will flow to the event egress which will be yet another datastream within the data stream job.

Is my understanding correct?

I was hoping that a stateful function could be called by a process function, is that possible? (I am guessing no).

Please let me know. 

Thank you.  Sincerely,

Marco A. Villalobos

[Marco Villalobos-2]

That is a more round-abou then I hoped for.  I was hoping that a process function could call a stateful function and receive and act upon the response, but that's not the case.  Thank you.

On Wed, Apr 7, 2021 at 11:38 AM Igal Shilman <[hidden email]> wrote:

Yes it is possible. A process function upstream to a stateful function can emit a message that

in turn will be routed to that function using the data stream integration.

On Wed, Apr 7, 2021 at 7:16 PM Marco Villalobos <[hidden email]> wrote:

Thank you for the clarification. 

BUT....there was one question not addressed:

Can a stateful function be called by a process function?

On Wed, Apr 7, 2021 at 8:19 AM Igal Shilman <[hidden email]> wrote:

Hello Marco!

Your understanding is correct, but in addition

You can also use StateFun within a DataStream application [1]

[1] https://ci.apache.org/projects/flink/flink-statefun-docs-master/docs/sdk/flink-datastream/

On Wed, Apr 7, 2021 at 2:49 AM Marco Villalobos <[hidden email]> wrote:

Upon reading about stateful functions, it seems as though first, a data stream has to flow to an event ingress.  Then, the stateful functions will perform computations via whatever functionality it provides. Finally, the results of said computations will flow to the event egress which will be yet another datastream within the data stream job.

Is my understanding correct?

I was hoping that a stateful function could be called by a process function, is that possible? (I am guessing no).

Please let me know. 

Thank you.  Sincerely,

Marco A. Villalobos