Why is data written through Kafka instead of directly into ClickHouse?

Data is written through Kafka, not directly into ClickHouse, for several reasons:

• Buffering and resilience: Kafka acts as a buffer, allowing data to be accumulated and processed asynchronously. If ClickHouse is temporarily unavailable, data is not lost.
• Scalability: Kafka scales well and can handle large data streams, distributing the load.
• Processing flexibility: data from Kafka can be consumed by different services, transformed, and aggregated before writing to ClickHouse.
• System separation: Kafka serves as an intermediate layer, simplifying architecture and increasing fault tolerance.

Thus, Kafka provides reliable, scalable, and flexible data transfer to ClickHouse, improving the overall system architecture.