Simulation run on this device. Scenario values are not sent anywhere — the engine is fully local.
system design simulation · free
Kafka Partition & Consumer Lab
Partition a topic, size a consumer group, and watch ordering constraints bind.
Why does consumer #9 sit idle while the lag grows?
Engine 1.0.0 · simulation
1256
1256
10100000
1300
- Active consumers
- 8
- Msgs / consumer / s
- 625.0
- Idle consumers
- 0
- Buffer for lag target
- 150000 msgs
Parallelism capped by partition count.
24 parts / 8 consumers
Method
- Deterministic local model of the mechanism — knobs recompute outputs instantly with no network.
- Numbers are teaching approximations, not production capacity guarantees.