[FLINK-4346] Implement basic RPC abstraction

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.5.0
• Component/s: Runtime / Coordination
• Labels: flip-6
• Assignee: Till Rohrmann
• Reporter: Stephan Ewen
• Created: 09/Aug/16 22:45
• Updated: 05/Feb/20 14:33
• Resolved: 13/Jul/18 07:33

Description

As part of refactoring of the cluster management, we can introduce a new RPC abstraction on top of our Akka-based distributed coordination.

It should address the following issues:

• Add type safety to the sender and receiver of messages. We want proper types methods to be called, rather than haveing generic message types and pattern matching everywhere. This is similar to typed actors.

• Make the message receivers testable without involving actors, i.e. the methods should be callable directly. When used with other component, the receiver will be wrapped in an actor that calls the methods based on received messages.

• We want to keep the paradigm of single-threaded execution per "actor"

There is some basic code layout in the following branch and commit:

https://github.com/apache/flink/tree/flip-6/flink-runtime/src/main/java/org/apache/flink/runtime/rpc

Issue Links

• blocks: FLINK-4319 Rework Cluster Management (FLIP-6)
• relates to: FLINK-4399 Add support for oversized messages
• relates to: FLINK-10718 Use IO executor in RpcService for message serialization
• relates to: FLINK-15924 Detect and log blocking main thread operations

Sub-Tasks

• Introduce Flink's own future abstraction: Resolved
• Auto generate message sender classes via Java Proxies: Resolved
• Eagerly initialize RrcProtocol members: Closed
• Buffer rpc calls until RpcEndpoint is properly started: Closed
• Check parameters for serializability before sending a remote RpcInvocation message: Closed
• Add a "scheduleRunAsync()" feature to the RpcEndpoint: Closed
• Add as way to assert that code runs in the RpcEndpoint's Main Thread: Closed
• Add throws clause verification to RpcCompletenessTest: Closed
• Make RPC Service Thread Safe: Closed
• RPC proxy classloading should use Flink class' classloader: Closed
• Remove restriction on RpcService.getAddress: Resolved
• Add a testing RPC service: Resolved
• Add support in RpcCompletenessTest for inheritance of RpcGateway and RpcEndpoint: Closed
• Throw exception when remote connection cannot be resolved: Closed
• Mark runAsync and scheduleAsync methods protected: Closed
• when call connect method in AkkaRpcService using same address and same rpc gateway class, the returned gateways are equal with respect to equals and hashCode: Closed
• Check that the RpcEndpoint supports the specified RpcGateway: Closed
• Port existing code to use Flink's future abstraction: Closed
• Allow RpcService to execute Callables in the RpcService executor: Closed
• Add getAddress method to RpcService: Closed
• Add wait for termination function to RpcEndpoints: Closed
• RpcCompletenessTest: Add support for type arguments and subclasses: Closed
• Let RpcEndpoint.start/shutDown throw exceptions: Closed
• Remove stashing from AkkaRpcActor: Closed
• Properly unpack thrown exceptions in RPC methods: Closed
• Let the RPCService provide a ScheduledExecutorService: Closed
• Let RpcService.scheduleRunnable return ScheduledFuture: Closed
• Allow to specify endpoint names: Closed
• Create SerialMainThreadValidatorUtil to support TestingSerialRpcService: Closed
• Remove TestingSerialRpcService: Closed
• Support fencing tokens to filter out outdated messages: Closed
• Add getPort method to RpcService: Closed
• Add callback for proper RpcEndpoint shut down: Closed
• Let RpcEndpoint directly implement RpcGateways: Closed
• Complete termination future after actor has been stopped.: Closed
• Simplify termination future completion: Closed
• Shut down AkkaRpcActors with PoisonPill: Closed
• Change termination future type of RpcEndpoint to Void: Closed
• Allow RpcEndpoint#postStop to complete asynchronously: Closed
• Make AkkaRpcService#stopService non-blocking: Closed
• Add UnfencedMainThreadExecutor to FencedRpcEndpoint: Closed
• Add support for scheduleRunAsync for FencedRpcEndpoints: Closed
• Add version information to remote rpc messages: Closed