KIP-21 — Dynamic Configuration

Accepted AdminBroker

Introduces a unified `DynamicConfigManager` backed by ZooKeeper that handles runtime configuration changes for multiple entity types (topics, clients) without rolling restarts, and adds `AlterConfig`/`DescribeConfig` network APIs. The existing configuration system required a full cluster rolling restart to change broker-level settings; only topic configs had a limited ZooKeeper-based dynamic update path.

Details