echooymxq

**Make sure set the target branch to `develop`** ## What is the purpose of the change * The others apis use `BrokerHeartbeatManager` just send heartbeat and check broker active status....

The current change BrokerRole implementation is detects the broker's heartbeat periodically. https://github.com/apache/rocketmq/blob/10e8e6b8ae565095cfa6c70fa07857e526a20d0d/controller/src/main/java/org/apache/rocketmq/controller/impl/DefaultBrokerHeartbeatManager.java#L77-L86 The above code, `iterator.remove()` remove first and with async notify mechanism to elect a master, if there are...