KvStateClientProxy (Flink : 2.0-preview1 API)

All Superinterfaces:

KvStateServer

All Known Implementing Classes:

KvStateClientProxyImpl
```
public interface KvStateClientProxy
extends KvStateServer
```
An interface for the Queryable State Client Proxy running on each Task Manager in the cluster.
This proxy is where the Queryable State Client (potentially running outside your Flink cluster) connects to, and his responsibility is to forward the client's requests to the rest of the entities participating in fetching the requested state, and running within the cluster.
These are:
1. the Job Manager, which is responsible for sending the Task Manager storing the requested state, and
2. the Task Manager having the state itself.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`KvStateLocationOracle`	`getKvStateLocationOracle(JobID jobId)`	Retrieves a future containing the currently leading key-value state location oracle.
`void`	`updateKvStateLocationOracle(JobID jobId, KvStateLocationOracle kvStateLocationOracle)`	Updates the active `Job Manager` in case of change.

Methods inherited from interface org.apache.flink.runtime.query.KvStateServer
getServerAddress, shutdown, start

- Method Detail
  - updateKvStateLocationOracle
```
void updateKvStateLocationOracle(JobID jobId,
                                 @Nullable
                                 KvStateLocationOracle kvStateLocationOracle)
```
    Updates the active Job Manager in case of change.
    This is useful in settings where high-availability is enabled and a failed Job Manager is replaced by a new one.
    IMPORTANT: this method may be called by a different thread than the getKvStateLocationOracle(JobID).
    
    Parameters:
    
    jobId - identifying the job for which to update the key-value state location oracle
    
    kvStateLocationOracle - the key-value state location oracle for the given JobID, or null if there is no oracle anymore
  - getKvStateLocationOracle
```
@Nullable
KvStateLocationOracle getKvStateLocationOracle(JobID jobId)
```
    Retrieves a future containing the currently leading key-value state location oracle.
    IMPORTANT: this method may be called by a different thread than the updateKvStateLocationOracle(JobID, KvStateLocationOracle).
    
    Parameters:
    
    jobId - identifying the job for which to request the key-value state location oracle
    
    Returns:
    
    The key-value state location oracle for the given JobID or null if none.