org.apache.flink.runtime.rpc

Interface RpcService

All Known Implementing Classes:

AkkaRpcService

public interface RpcService

Interface for rpc services. An rpc service is used to start and connect to a RpcEndpoint. Connecting to a rpc server will return a RpcGateway which can be used to call remote procedures.

Method Summary

Modifier and Type	Method and Description
<C extends RpcGateway> CompletableFuture<C>	connect(String address, Class<C> clazz) Connect to a remote rpc server under the provided address.
<F extends Serializable,C extends FencedRpcGateway<F>> CompletableFuture<C>	connect(String address, F fencingToken, Class<C> clazz) Connect to a remote fenced rpc server under the provided address.
<T> CompletableFuture<T>	execute(Callable<T> callable) Execute the given callable and return its result as a CompletableFuture.
void	execute(Runnable runnable) Execute the given runnable in the executor of the RPC service.
<F extends Serializable> RpcServer	fenceRpcServer(RpcServer rpcServer, F fencingToken) Fence the given RpcServer with the given fencing token.
String	getAddress() Return the hostname or host address under which the rpc service can be reached.
Executor	getExecutor() Gets the executor, provided by this RPC service.
int	getPort() Return the port under which the rpc service is reachable.
ScheduledExecutor	getScheduledExecutor() Gets a scheduled executor from the RPC service.
CompletableFuture<Void>	getTerminationFuture() Returns a future indicating when the RPC service has been shut down.
ScheduledFuture<?>	scheduleRunnable(Runnable runnable, long delay, TimeUnit unit) Execute the runnable in the execution context of this RPC Service, as returned by getExecutor(), after a scheduled delay.
<C extends RpcEndpoint & RpcGateway> RpcServer	startServer(C rpcEndpoint) Start a rpc server which forwards the remote procedure calls to the provided rpc endpoint.
void	stopServer(RpcServer selfGateway) Stop the underlying rpc server of the provided self gateway.
CompletableFuture<Void>	stopService() Trigger the asynchronous stopping of the RpcService.

Method Detail

getAddress

String getAddress()

Return the hostname or host address under which the rpc service can be reached. If the rpc service cannot be contacted remotely, then it will return an empty string.

Returns:

Address of the rpc service or empty string if local rpc service

getPort

int getPort()

Return the port under which the rpc service is reachable. If the rpc service cannot be contacted remotely, then it will return -1.

Returns:

Port of the rpc service or -1 if local rpc service

connect

<C extends RpcGateway> CompletableFuture<C> connect(String address,
                                                    Class<C> clazz)

Connect to a remote rpc server under the provided address. Returns a rpc gateway which can be used to communicate with the rpc server. If the connection failed, then the returned future is failed with a RpcConnectionException.

Type Parameters:

C - Type of the rpc gateway to return

Parameters:

address - Address of the remote rpc server

clazz - Class of the rpc gateway to return

Returns:

Future containing the rpc gateway or an RpcConnectionException if the connection attempt failed

connect

<F extends Serializable,C extends FencedRpcGateway<F>> CompletableFuture<C> connect(String address,
                                                                                    F fencingToken,
                                                                                    Class<C> clazz)

Connect to a remote fenced rpc server under the provided address. Returns a fenced rpc gateway which can be used to communicate with the rpc server. If the connection failed, then the returned future is failed with a RpcConnectionException.

Type Parameters:

F - Type of the fencing token

C - Type of the rpc gateway to return

Parameters:

address - Address of the remote rpc server

fencingToken - Fencing token to be used when communicating with the server

clazz - Class of the rpc gateway to return

Returns:

Future containing the fenced rpc gateway or an RpcConnectionException if the connection attempt failed

startServer

<C extends RpcEndpoint & RpcGateway> RpcServer startServer(C rpcEndpoint)

Start a rpc server which forwards the remote procedure calls to the provided rpc endpoint.

Type Parameters:

C - Type of the rpc endpoint

Parameters:

rpcEndpoint - Rpc protocol to dispatch the rpcs to

Returns:

Self gateway to dispatch remote procedure calls to oneself

fenceRpcServer

<F extends Serializable> RpcServer fenceRpcServer(RpcServer rpcServer,
                                                  F fencingToken)

Fence the given RpcServer with the given fencing token.

Fencing the RpcServer means that we fix the fencing token to the provided value. All RPCs will then be enriched with this fencing token. This expects that the receiving RPC endpoint extends FencedRpcEndpoint.

Type Parameters:

F - type of the fencing token

Parameters:

rpcServer - to fence with the given fencing token

fencingToken - to fence the RpcServer with

Returns:

Fenced RpcServer

stopServer

void stopServer(RpcServer selfGateway)

Stop the underlying rpc server of the provided self gateway.

Parameters:

selfGateway - Self gateway describing the underlying rpc server

stopService

CompletableFuture<Void> stopService()

Trigger the asynchronous stopping of the RpcService.

Returns:

Future which is completed once the RpcService has been fully stopped.

getTerminationFuture

CompletableFuture<Void> getTerminationFuture()

Returns a future indicating when the RPC service has been shut down.

Returns:

Termination future

getExecutor

Executor getExecutor()

Gets the executor, provided by this RPC service. This executor can be used for example for the handleAsync(...) or thenAcceptAsync(...) methods of futures.

IMPORTANT: This executor does not isolate the method invocations against any concurrent invocations and is therefore not suitable to run completion methods of futures that modify state of an RpcEndpoint. For such operations, one needs to use the MainThreadExecutionContext of that RpcEndpoint.

Returns:

The execution context provided by the RPC service

getScheduledExecutor

ScheduledExecutor getScheduledExecutor()

Gets a scheduled executor from the RPC service. This executor can be used to schedule tasks to be executed in the future.

IMPORTANT: This executor does not isolate the method invocations against any concurrent invocations and is therefore not suitable to run completion methods of futures that modify state of an RpcEndpoint. For such operations, one needs to use the MainThreadExecutionContext of that RpcEndpoint.

Returns:

The RPC service provided scheduled executor

scheduleRunnable

ScheduledFuture<?> scheduleRunnable(Runnable runnable,
                                    long delay,
                                    TimeUnit unit)

Execute the runnable in the execution context of this RPC Service, as returned by getExecutor(), after a scheduled delay.

Parameters:

runnable - Runnable to be executed

delay - The delay after which the runnable will be executed

execute

void execute(Runnable runnable)

Execute the given runnable in the executor of the RPC service. This method can be used to run code outside of the main thread of a RpcEndpoint.

IMPORTANT: This executor does not isolate the method invocations against any concurrent invocations and is therefore not suitable to run completion methods of futures that modify state of an RpcEndpoint. For such operations, one needs to use the MainThreadExecutionContext of that RpcEndpoint.

Parameters:

runnable - to execute

execute

<T> CompletableFuture<T> execute(Callable<T> callable)

Execute the given callable and return its result as a CompletableFuture. This method can be used to run code outside of the main thread of a RpcEndpoint.

IMPORTANT: This executor does not isolate the method invocations against any concurrent invocations and is therefore not suitable to run completion methods of futures that modify state of an RpcEndpoint. For such operations, one needs to use the MainThreadExecutionContext of that RpcEndpoint.

Type Parameters:

T - is the return value type

Parameters:

callable - to execute

Returns:

Future containing the callable's future result