Thanks. I was curious about the other real world use cases i.e what do people
use it for ? Is this widely used or mostly for debugging purposes ? Any caveats
?
Thanks
Mohan
On 10/1/20, 5:55 PM, "Guozhang Wang" <wangg...@gmail.com> wrote:
Mohan,
I think you can build a REST API on top of app1 directly leveraging on its
IQ interface. For some examples code you can refer to
https://github.com/confluentinc/kafka-streams-examples/tree/6.0.0-post/src/main/java/io/confluent/examples/streams/interactivequeries
Guozhang
On Thu, Oct 1, 2020 at 10:40 AM Parthasarathy, Mohan <mpart...@hpe.com>
wrote:
> Hi Guozhang,
>
> The async event trigger process is not running as a kafka streams
> application. It offers REST interface where other applications post events
> which in turn needs to go through App1's state and send requests to App2
> via Kafka. Here is the diagram:
>
> KafkaTopics---> App1 ---> App2
> |
> V
> REST ---->App3
>
> REST API to App3 and read the local store of App1 (IQ) and send requests
> to App2 (through kafka topic, not shown above). Conceptually it looks
same
> as your use case. What do people do if a kafka streams application (App1)
> has to offer REST interface also ?
>
> -thanks
> Mohan
>
> On 9/30/20, 5:01 PM, "Guozhang Wang" <wangg...@gmail.com> wrote:
>
> Hello Mohan,
>
> If I understand correctly, your async event trigger process runs out
> of the
> streams application, that reads the state stores of app2 through the
> interactive query interface, right? This is actually a pretty common
> use
> case pattern for IQ :)
>
>
> Guozhang
>
> On Wed, Sep 30, 2020 at 1:22 PM Parthasarathy, Mohan <mpart...@hpe.com
> >
> wrote:
>
> > Hi,
> >
> > A traditional kafka streams application (App1) reading data from a
> kafka
> > topic, doing aggregations resulting in some local state. The output
> of this
> > application is consumed by a different application(App2) for doing a
> > different task. Under some conditions, there is an external trigger
> (async
> > event) which needs to trigger requests for all the keys in the local
> store
> > to App2. To achieve this, we can read the local stores from all the
> > replicas and send the request to App2.
> >
> > This async event happens less frequently compared to the normal case
> that
> > leads to the state creation in the first place. Are there any
> caveats doing
> > it this way ? If not, any other suggestions ?
> >
> > Thanks
> > Mohan
> >
> >
>
> --
> -- Guozhang
>
>
>
--
-- Guozhang
