Introduction

This wiki explains the design for decoupling the how to decouple Druid service calls by calling using the Sunbird-Obsrv API service.

Background & Problem Statement

At Currently, the moment LERN Batch Service is connecting connects directly to the Druid data store for fetching to fetch collection summary aggregate data using a druid query on the "audit-rollup-syncts" and "telemetry-events-syncts" data sources. This direct connection creates tight coupling between the LERN Batch Service and the Druid data store. The new design will fetch the same information by connecting with proposes to decouple this connection by using the API service owned by obsrvBB.

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Design

To decouple achieve the goal of decoupling the above druid Druid calls, we propose the following solution:

Solution 1:
We can call the existing new API service designed by obsrvBB by building the required request payload in LERN batch servicewhich in turn connects to the druid the LERN Batch Service. This API service will then connect to the Druid data store to query "audit-rollup-syncts" and "telemetry-events-syncts" data sources which will give and return the collection summary aggregate data as the a response back to the LERN batch service which can Batch Service. This response can then be used for further computations.

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