Hi Nizam,

Please find my response below:

1. Where is the stream service actually used? Any usecases? The Stream service enables asynchronous flow of data between processes in Pega Platform.(What does it mean?)
   • Stream Service is used externally by decisioning customers for realtime streams processing. For example, reading streams of web-clicks via the Stream Service and aggregating them using event strategies. Internally, Queue processors use Stream Service to queue indexing data for Search.

1. Does it invoke Zookeeper, Broker automatically?
   • We have our native, zookeeper compatible server implementation, called Charlatan. Charlatan provides zookeeper capabilities, using Pega platform database schema.
2. It comes with Kafka 1.11 version in 8.3. Can I upgrade this to higher version?
   • Kafka version can only be upgraded as part of platform upgrades. However, from Pega Version 8.4 onward, we are adding support for External Kafka. Which means, On-prem customers can run there own Kafka cluster and use it for Stream Service. 
3. What is the value add of using Stream Dataset vs Kafka Dataset? Both are same now??
   • In principle, it is true that both of them uses Kafka as the underlying technology. However, Stream datasets are more native to the platform. OOTB used by Platform components like Queue Processors, Decisioning. 
4. What is the version from which the stream service is using Kafka? Is it from 7.4 or 8??
   • 7.4

Let me know if you would like to know more about Stream Service?

Regards,

Vidya