itsual Backpressure and Flow Control
Overview
Without backpressure, fast producers can overwhelm slow consumers, leading to unbounded queues, memory exhaustion, and cascading failures.
When to Use
- Streaming data pipelines
- Message consumers and event processors
- Any system with producers and consumers operating at different speeds
Techniques
- Bounded queues with clear overflow behavior
- Reactive streams / async pull-based models
- Rate limiting and load shedding
- Credit-based or window-based flow control
- Circuit breaking when downstream is unhealthy
Principles
- Prefer signaling upstream to slow down over unbounded buffering
- Make overload behavior explicit and observable
- Drop, sample, or reject work according to clear policy when necessary
Verification
- System remains stable when consumers slow down or stop
- Overload behavior is tested and documented
- Key metrics (queue depth, drop rate, latency) are visible