max.warmup.replicas — Kafka Kafka Streams Configuration
The maximum number of warmup replicas (extra standbys beyond the configured num.standbys) that can be assigned at once for the purpose of keeping the task available on one instance while it is warming up on another instance it has been reassigned to.
Description
The maximum number of warmup replicas (extra standbys beyond the configured num.standbys) that can be assigned at once for the purpose of keeping the task available on one instance while it is warming up on another instance it has been reassigned to. Used to throttle how much extra broker traffic and cluster state can be used for high availability. Must be at least 1.Note that one warmup replica corresponds to one Stream Task. Furthermore, note that each warmup replica can only be promoted to an active task during a rebalance (normally during a so-called probing rebalance, which occur at a frequency specified by the `probing.rebalance.interval.ms` config). This means that the maximum rate at which active tasks can be migrated from one Kafka Streams Instance to another instance can be determined by (`max.warmup.replicas` / `probing.rebalance.interval.ms`).
Default Values by Kafka Version
| Kafka Version | Default Value |
|---|---|
| 2.6 | 2 |
| 2.7 | 2 |
| 2.8 | 2 |
| 3.0 | 2 |
| 3.1 | 2 |
| 3.2 | 2 |
| 3.3 | 2 |
| 3.4 | 2 |
| 3.5 | 2 |
| 3.6 | 2 |
| 3.7 | 2 |
| 3.8 | 2 |
| 3.9 | 2 |
| 4.0 | 2 |
| 4.1 | 2 |
| 4.2 | 2 |