> For the complete documentation index, see [llms.txt](https://lern.sunbird.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lern.sunbird.org/use/developer-guide/ml-service/data-pipeline-flink-jobs/program-flink-job/component-diagram.md).

# Component Diagram

<figure><img src="https://308610995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F4ZKyfmmhMWpPkD6iYvKF%2Fuploads%2FDZG6lfck6mefxp3FFnFv%2Fimage.png?alt=media&amp;token=1287eda5-c020-40f1-abb4-9cb5810a803f" alt=""><figcaption></figcaption></figure>

The Program User Info service is constructed upon the framework of Flink, Kafka and Cassandra, a powerful approach for processing and managing data in a scalable and real-time manner.

1. **Apache Kafka** is a distributed event streaming platform that is designed for handling high volumes of real-time data. In this service Kafka produces user information as an event of type JSON.
2. **Apache Flink** is a stream processing framework that provides high-throughput, low-latency, and exactly-once processing of streaming data. Flink consumes the event from Kafka and flattens the JSON. This process involves taking nested JSON structures and transforming them into a simpler, one-level structure where all the fields are at the top level.
3. **Apache Cassandra** is a distributed NoSQL database that is designed to handle massive amounts of data across many commodity servers, ensuring high availability and fault tolerance. Once the data is flattened it will be stored in Cassandra database.

**Configuration variables:**

<table><thead><tr><th width="246">Variable</th><th>Default Value</th><th>Purpose</th></tr></thead><tbody><tr><td>kafka.input.topic</td><td>{{env}}.programuser.info</td><td>Kafka topic from which messages/events are read to be processed.</td></tr><tr><td>kafka.groupId</td><td>{{env}}-programuser-group</td><td>Kafka input topic group Id</td></tr><tr><td>ml-cassandra.keyspace</td><td>sunbird_programs</td><td>Cassandra keyspace name</td></tr><tr><td>ml-cassandra.table</td><td>program_enrollment</td><td>Cassandra table used to store user data</td></tr></tbody></table>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://lern.sunbird.org/use/developer-guide/ml-service/data-pipeline-flink-jobs/program-flink-job/component-diagram.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.