IWorkerHook (Storm 2.7.1 API)

All Superinterfaces:

Serializable

All Known Implementing Classes:

BaseWorkerHook
```
public interface IWorkerHook
extends Serializable
```
An IWorkerHook represents a topology component that can be executed when a worker starts, and when a worker shuts down. It can be useful when you want to execute operations before topology processing starts, or cleanup operations before your workers shut down.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`shutdown()`	This method is called right before a worker shuts down.
`default void`	`start(Map<String,Object> topoConf, WorkerTopologyContext context)`	Deprecated. see `start(Map, WorkerUserContext)`
`default void`	`start(Map<String,Object> topoConf, WorkerUserContext context)`	This method is called when a worker is started and can be used to do necessary prep-processing and allow initialization of shared application state.

- Method Detail
  - start
```
default void start(Map<String,Object> topoConf,
                   WorkerTopologyContext context)
```
    Deprecated.
    see start(Map, WorkerUserContext)
    
    This method is called when a worker is started.
    
    Parameters:
    
    topoConf - The Storm configuration for this worker
    
    context - This object can be used to get information about this worker's place within the topology
  - start
```
default void start(Map<String,Object> topoConf,
                   WorkerUserContext context)
```
    This method is called when a worker is started and can be used to do necessary prep-processing and allow initialization of shared application state.
    
    Parameters:
    
    topoConf - The Storm configuration for this worker
    
    context - This object can be used to get information about this worker's place within the topology and exposes WorkerUserContext.setResource(String, Object) to set the shared application state.
  - shutdown
```
void shutdown()
```
    This method is called right before a worker shuts down.