Re: can kafka state stores be used as a application level cache by application to modify it from outside the stream topology?

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Yes.

A `GlobalKTable` uses a global store internally.

You can also use `StreamsBuilder.addGlobalStore()` or
`Topology.addGlobalStore()` to add a global store "manually".


-Matthias


On 4/30/20 7:42 AM, Pushkar Deole wrote:
> Thanks Matthias.
> Can you elaborate on the replicated caching layer part?
> When you say global stores, do you mean GlobalKTable created from a topic
> e.g. using StreamsBuilder.globalTable(String topic) method ?
>
> On Thu, Apr 30, 2020 at 12:44 PM Matthias J. Sax <mjsax@apache.org> wrote:
>
>> It's not possible to modify state store from "outside".
>>
>> If you want to build a "replicated caching layer", you could use global
>> stores and write into the corresponding topics to update all stores. Of
>> course, those updates would be async.
>>
>>
>> -Matthias
>>
>> On 4/29/20 10:52 PM, Pushkar Deole wrote:
>>> Hi All,
>>>
>>> I am wondering if this is possible: i have been asked to use state stores
>>> as a general replicated cache among multiple instances of service
>> instances
>>> however the state store is created through streambuilder but is not
>>> actually modified through stream processor topology however it is to be
>>> modified from outside the stream topology. So, essentially, the state
>> store
>>> is just to be created from streambuilder and then to be used as an
>>> application level cache that will get replicated between application
>>> instances. Is this possible using state stores?
>>>
>>> Secondly, if possible, is this a good design approach?
>>>
>>> Appreciate your response since I don't know the internals of state
>> stores.
>>>
>>
>>
>