# Package org.apache.storm.nimbus

- Interface Summary
  Interface | Description
  --- | ---
  ILeaderElector | The interface for leader election.
  ITopologyActionNotifierPlugin | A plugin interface that gets invoked any time there is an action for a topology.
  ITopologyValidator |
  IWorkerHeartbeatsRecoveryStrategy | Interface for strategy to recover heartbeats when master gains leadership.

- Class Summary
  Class | Description
  --- | ---
  AssignmentDistributionService | A service for distributing master assignments to supervisors, this service makes the assignments notification asynchronous.
  DefaultTopologyValidator |
  LeaderListenerCallback | A callback function when nimbus gains leadership.
  NimbusHeartbeatsPressureTest | Test for nimbus heartbeats max throughput, This is a client to collect the statistics.
  NimbusInfo |
  StrictTopologyValidator |
  TimeOutWorkerHeartbeatsRecoveryStrategy | Wait for a node to report worker heartbeats until a configured timeout.
  WorkerHeartbeatsRecoveryStrategyFactory | Factory class for recovery strategy.