HeartbeatManager (Flink : 2.0-SNAPSHOT API)

Type Parameters:

I - Type of the incoming payload

O - Type of the outgoing payload

All Superinterfaces:

HeartbeatTarget<I>

All Known Implementing Classes:

NoOpHeartbeatManager
```
public interface HeartbeatManager<I,O>
extends HeartbeatTarget<I>
```
A heartbeat manager has to be able to start/stop monitoring a HeartbeatTarget, and report heartbeat timeouts for this target.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`long`	`getLastHeartbeatFrom(ResourceID resourceId)`	Returns the last received heartbeat from the given target.
`void`	`monitorTarget(ResourceID resourceID, HeartbeatTarget<O> heartbeatTarget)`	Start monitoring a `HeartbeatTarget`.
`void`	`stop()`	Stops the heartbeat manager.
`void`	`unmonitorTarget(ResourceID resourceID)`	Stops monitoring the heartbeat target with the associated resource ID.

Methods inherited from interface org.apache.flink.runtime.heartbeat.HeartbeatTarget
receiveHeartbeat, requestHeartbeat

- Method Detail
  - monitorTarget
```
void monitorTarget(ResourceID resourceID,
                   HeartbeatTarget<O> heartbeatTarget)
```
    Start monitoring a HeartbeatTarget. Heartbeat timeouts for this target are reported to the HeartbeatListener associated with this heartbeat manager.
    
    Parameters:
    
    resourceID - Resource ID identifying the heartbeat target
    
    heartbeatTarget - Interface to send heartbeat requests and responses to the heartbeat target
  - unmonitorTarget
```
void unmonitorTarget(ResourceID resourceID)
```
    Stops monitoring the heartbeat target with the associated resource ID.
    
    Parameters:
    
    resourceID - Resource ID of the heartbeat target which shall no longer be monitored
  - stop
```
void stop()
```
    Stops the heartbeat manager.
  - getLastHeartbeatFrom
```
long getLastHeartbeatFrom(ResourceID resourceId)
```
    Returns the last received heartbeat from the given target.
    
    Parameters:
    
    resourceId - for which to return the last heartbeat
    
    Returns:
    
    Last heartbeat received from the given target or -1 if the target is not being monitored.