Which three thread pools are involved in flow processing?

• A. Inbound, Processing, and Outbound
• B. Receiving (message sources threads), Flow Processing (message processor's threads), Dispatching (outbound endpoints threads)
• C. Source, Processor, and Transport
• D. Input, Compute, Output

Answer: (B)

In flow processing, three thread pools handle different parts of the work to keep things responsive and scalable. The receiving pool covers threads that listen for and accept messages from sources. The flow processing pool runs the internal processors of the flow—transformations, routing logic, filters, and the like. The dispatching pool is responsible for the outbound side, managing threads that send messages to outbound endpoints and perform related I/O. This separation allows incoming messages to be accepted promptly, the flow’s processing to proceed without blocking I/O, and outbound operations to be handled independently, improving throughput and scalability.