What are fan-in and fan-out in the context of Akka Streams? Can you describe some scenarios where they might be useful?
Fan-in and fan-out are concepts in Akka Streams related to the flow of data through stream processing components. Fan-in refers to multiple input streams converging into a single output stream, while fan-out is the opposite, where a single input stream diverges into multiple output streams.
In fan-in scenarios, one might use Merge or Concat stages to combine several sources of data for further processing. For example, merging logs from different servers to analyze them collectively. Another scenario could be aggregating sensor readings from various IoT devices for real-time monitoring.
Fan-out situations often involve Broadcast or Balance stages to distribute incoming data across multiple downstream components. This can be useful when implementing load balancing strategies or parallelizing tasks for performance improvements. An example would be distributing user requests among available backend services or splitting a large dataset into smaller chunks for concurrent processing by worker nodes.
