org.apache.flink.runtime.query

Interface KvStateClientProxy

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

Modifier and Type	Method and 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.