org.apache.flink.queryablestate.server

Class KvStateServerHandler

java.lang.Object

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

org.apache.flink.queryablestate.network.AbstractServerHandler<KvStateInternalRequest,KvStateResponse>

org.apache.flink.queryablestate.server.KvStateServerHandler

All Implemented Interfaces:

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler, org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

@Internal
 @ChannelHandler.Sharable
public class KvStateServerHandler
extends AbstractServerHandler<KvStateInternalRequest,KvStateResponse>

This handler dispatches asynchronous tasks, which query InternalKvState instances and write the result to the channel.

The network threads receive the message, deserialize it and dispatch the query task. The actual query is handled in a separate thread as it might otherwise block the network threads (file I/O etc.).

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler.Sharable

Field Summary

Fields inherited from class org.apache.flink.queryablestate.network.AbstractServerHandler

queryExecutor

Constructor Summary

Constructors

Constructor and Description
KvStateServerHandler(KvStateServerImpl server, KvStateRegistry kvStateRegistry, MessageSerializer<KvStateInternalRequest,KvStateResponse> serializer, KvStateRequestStats stats) Create the handler used by the KvStateServerImpl.

Method Summary

Modifier and Type	Method and Description
CompletableFuture<KvStateResponse>	handleRequest(long requestId, KvStateInternalRequest request) Handles an incoming request and returns a CompletableFuture containing the corresponding response.
CompletableFuture<Void>	shutdown() Shuts down any handler-specific resources, e.g.

Methods inherited from class org.apache.flink.queryablestate.network.AbstractServerHandler

channelActive, channelInactive, channelRead, exceptionCaught, getServerName

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, userEventTriggered

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

Constructor Detail

KvStateServerHandler

public KvStateServerHandler(KvStateServerImpl server,
                            KvStateRegistry kvStateRegistry,
                            MessageSerializer<KvStateInternalRequest,KvStateResponse> serializer,
                            KvStateRequestStats stats)

Create the handler used by the KvStateServerImpl.

Parameters:

server - the KvStateServerImpl using the handler.

kvStateRegistry - registry to query.

serializer - the MessageSerializer used to (de-) serialize the different messages.

stats - server statistics collector.

Method Detail

handleRequest

public CompletableFuture<KvStateResponse> handleRequest(long requestId,
                                                        KvStateInternalRequest request)

Description copied from class: AbstractServerHandler

Handles an incoming request and returns a CompletableFuture containing the corresponding response.

NOTE: This method is called by multiple threads.

Specified by:

handleRequest in class AbstractServerHandler<KvStateInternalRequest,KvStateResponse>

Parameters:

requestId - the id of the received request to be handled.

request - the request to be handled.

Returns:

A future with the response to be forwarded to the client.

shutdown

public CompletableFuture<Void> shutdown()

Description copied from class: AbstractServerHandler

Shuts down any handler-specific resources, e.g. thread pools etc and returns a CompletableFuture.

If an exception is thrown during the shutdown process, then that exception will be included in the returned future.

Specified by:

shutdown in class AbstractServerHandler<KvStateInternalRequest,KvStateResponse>

Returns:

A CompletableFuture that will be completed when the shutdown process actually finishes.