0.1 框架图
nn
+-------------------------------------------------+ +------------------------------------------------------------+
| | | |
v rpcServer | v |
NameNode ◇ -------------------------------------> NameNodeRpcServer ---------▷ NamenodeProtocols |
◇ | ◆ | | +-----------------+ |
| | 1 | | | |ClientProtocol | |
| o--> initialize() serviceRpcServer| o---> start() | |DatanodeProtocol | |
| | | | | | +-----▷ |NamenodeProtocol | |
| | clientRpcServer| | | 3 |HAServiceProtocol| |
| o--> loadNamesystem()----\ ★ | | |--> clientRpcServer.start() +-----------------+ |
| | \ | | | |
| o--> createRpcServer() \ | | |--> serverRpcServer.start() |
| | \ | | 13 |
| o--> startCommonServices() \ | o---> delete() |
| | | \ | | | |
| | 2 \ | | | 14 |
| namesystem |--> rpcServer.start() \ | o---> namesystem.delete() |
| | | | | |
| | | | |
FSNamesystem.loadFromDisk() <----------------------+ | |
| |
+----------------------------------------------------------+ |
| |
| ipc.Server |
| △ | |
| | |---------------------------------------------------------------------------------------- |
| | | Inner class +-- Listener (listens on the socket, create jobs for handler threads) |
| | | | | | ◆ |
| | | | | | | readers |
| | | v | | +-------------------> Reader() |
| | | | | | |
| | | | | o--> run() |
| | | Selector | o--> run():loop | | readSelector.select() |
| | | | | | selector.select() | 6 |
| | | | | | 5 o---> doRead() +----------------> Connection |
| | | NIO | o---> doAccept() | | |
| | | | | o---> c.readAndProcess() |
| | | | | | | channelRead(ByteBuffer) |
| | | | o--> reader.addConnection(c) | |
| | | | o--> processOneRpc() |
| | | | | | |
| | | | | 7 |
| | | Thread ◁ -----+-- Responder (sends responses of RPC back to clients) o--> processRpcRequest() |
| | | | | | |
| | | | o--> run() | |
| | | | | Call(rpcRequest) <--o |
| | | | | / |
| | | NIO | o--> doRunLoop() / |
| | | | | / |
| | | | / callQueue.put(call) |
| | | | / |
| | | | / |
| | | | / |
| | | | / |
| | | +-- Handler (handles queued calls) / |
| | | | / |
| | | | / |
| | | o---> run():loop / |
| | | | call / |
| | | | / |
| | | |---> callQueue.take() --------------------/ |
| | | | |
| | | |---> CurCall.set(call) |
| | | | 8 |
| | | |---> call() |
| | | ^ | |
| | | | |---> CurCall.set(null) |
| | | | |
| | | Inner class |
| | |---------------------------------------------------------- |
| | | |
| | o---> registerProtocolEngine() |
| | | |
| | o---> getRpcInvoker() |
| | | RpcInvoker |
| | o---> call() |--> responder.start() △ |
| | | 4 | | |
| | o---> start() -------+--> listener.start() o---> invoke() |
| | | | | |
| | |--> handler.start() ★ | |
v | (clientRpcServer) | |
RPC.Server ◁ ------------------------------------------ ProtobufRpcEngine.Server | |
| | | |
| |---------------------| |
o---> addProtocol() | Inner class | |
| | | | |
o---> registerProtocolAndImpl() | | | |
| | v ProtoBufRpcInvoker |
| 8.1 | ^ | |
o---> call() | / | |
| | +-------------------/ o---> getProtocolImpl() |
| | rpcKind = RPC_PROTOCOL_BUFFER | | | |
|---> getRpcInvoker() --------------------+ | | 8.3 |
| | | o---> call() |
| 8.2 | ^ | |
|---> call() | | | 9 |
| | |--> service.callBlockingMethod() |
| Inner class | | |
|--------------------- | |
+--------------------------+ |
ClientNamenodeProtocol.proto | |
+--------------------------------------+ | |
| | 12 | | |
|service ClientNamenodeProtocol { | server.delete()<--o | |
| rpc delete(DeleteRequestProto) | | | |
| returns(DeleteResponseProto); | | | |
|} | o-->DeleteRequestProto | |
+--------------------------------------+ | | |
auto | gen ClientProtocol | 11 | | |
| | o--> delete() | |
| | | | |
v @ProtocolInfo(Name, Ver) | | |
ClientNamenodeProtocol ClientNamenodeProtocolPB ◁ -------- ClientNamenodeProtocolServerSideTranslatorPB | |
| | / ◆ | |
| | +-------------/ | | |
| BlockingInterface ◁ ---------------+ | | server | |
| △ | +----------------+
| | v |
| | BlockingService(impl) <---------------------------------------------------+
| BlockingStub <----+ ^ |
| | | |
| | new | o--> getDescriptorForType()
| | | |
o---> newBlockingStub() ---+ | |
| | o--> getRequestPrototype()
| | |
o---> newReflectiveBlockingService()---------+ |
o--> getResponsePrototype()
|
|
o--> callBlockingMethod()
| |
| | 10
| o--> impl.delete()Delete操作从Namenode类出发经过NameNodeRpcServer启动各种服务, 最终回到NameNodeRpcServer中的delete方法. ipc.Server: 负责网络收发 (基类) RPC.Server: 负责PB协议维护 ProtobufRpcEngine.Server: 负责执行call
