HeartbeatTarget (Flink : 2.0-SNAPSHOT API)

Type Parameters:

I - Type of the payload which is sent to the heartbeat target

All Known Subinterfaces:

HeartbeatManager<I,O>

All Known Implementing Classes:

HeartbeatReceiver, HeartbeatSender, NoOpHeartbeatManager
```
public interface HeartbeatTarget<I>
```
Interface for components which can be sent heartbeats and from which one can request a heartbeat response. Both the heartbeat response as well as the heartbeat request can carry a payload. This payload is reported to the heartbeat target and contains additional information. The payload can be empty which is indicated by a null value.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`CompletableFuture<Void>`	`receiveHeartbeat(ResourceID heartbeatOrigin, I heartbeatPayload)`	Sends a heartbeat response to the target.
`CompletableFuture<Void>`	`requestHeartbeat(ResourceID requestOrigin, I heartbeatPayload)`	Requests a heartbeat from the target.

- Method Detail
  - receiveHeartbeat
```
CompletableFuture<Void> receiveHeartbeat(ResourceID heartbeatOrigin,
                                         I heartbeatPayload)
```
    Sends a heartbeat response to the target. Each heartbeat response can carry a payload which contains additional information for the heartbeat target.
    
    Parameters:
    
    heartbeatOrigin - Resource ID identifying the machine for which a heartbeat shall be reported.
    
    heartbeatPayload - Payload of the heartbeat. Null indicates an empty payload.
    
    Returns:
    
    Future that is completed exceptionally if the heartbeat response could not be sent to the target
  - requestHeartbeat
```
CompletableFuture<Void> requestHeartbeat(ResourceID requestOrigin,
                                         I heartbeatPayload)
```
    Requests a heartbeat from the target. Each heartbeat request can carry a payload which contains additional information for the heartbeat target.
    
    Parameters:
    
    requestOrigin - Resource ID identifying the machine issuing the heartbeat request.
    
    heartbeatPayload - Payload of the heartbeat request. Null indicates an empty payload.
    
    Returns:
    
    Future that is completed exceptionally if the heartbeat request could not be sent to the target