1.什么是Akka remoting？
Akka-Remoting一种ActorSystem之间Actor对Actor点对点的沟通协议.通过Akka-Remoting来实现一个ActorSystem中的一个Actor与另一个ActorSystem中的另一个Actor之间的沟通
Akka Remoting限制：
不支持NAT（Network Address Translation）
不支持负载均衡器（Load Balancers）
Akka提供了种方式来使用Remoting功能：
通过调用actorSelection方法搜索一个actor，该方法输入的参数的模式为：akka.<protocol>://<actor system>@<hostname>:<port>/<actor path>
通过actorOf方法创建一个actor
下面看一下Remoting系统中故障恢复模型（Failure Recovery Model），如下图所示：
上图中，连接到一个远程系统的过程中，包括上面4种状态：在进行任何通信之前，系统处于Idle状态；当第一次一个消息尝试向远程系统发送，或者当远程系统连接过来，这时系统状态变为Active；当两个系统通信失败，连接丢失，这时系统变为Gated状态；当系统通信过程中，由于参与通信的系统的状态不一致导致系统无法恢复，这时远程系统变为Quarantined状态，只有重新启动系统才能恢复，重启后系统变为Active状态。
Akka Remoting的功能
Akka将remoting完全配置化了，使用时几乎只需要修改配置文件，除非自定义，否则不需要动一行代码。 remoting包提供了两个功能：
查找一个已存在的远程Actor
在指定的远程路径上创建一个远程Actor
2.代码管理
实验目标
实现客户端和服务端双向通信
pom.xml
<!-- Akka Streams --><dependency><groupId>com.typesafe.akka</groupId><artifactId>akka-stream_2.13</artifactId><version>2.6.0</version></dependency>
server
server.conf
akka {actor {provider = "akka.remote.RemoteActorRefProvider"}remote {artery {enabled = ontransport = tcpcanonical.hostname = "127.0.0.1"canonical.port = 2552}}}
package com.et.akka.remoting;import akka.actor.AbstractActor;import akka.actor.ActorRef;import akka.actor.ActorSystem;import akka.actor.Props;import com.typesafe.config.ConfigFactory;public class ServerApp {static class ServerActor extends AbstractActor {@Overridepublic Receive createReceive() {return receiveBuilder().match(String.class, msg -> {System.out.println("Server received message: " + msg);getSender().tell("Hello from Server", getSelf());}).build();}}public static void main(String[] args) {ActorSystem system = ActorSystem.create("RemoteSystem", ConfigFactory.load("server"));ActorRef serverActor = system.actorOf(Props.create(ServerActor.class), "serverActor");System.out.println("Server is running...");}}
client
client.conf
akka {actor {provider = "akka.remote.RemoteActorRefProvider"}remote {artery {enabled = ontransport = tcpcanonical.hostname = "127.0.0.1"canonical.port = 0}}}
package com.et.akka.remoting;import akka.actor.AbstractActor;import akka.actor.ActorRef;import akka.actor.ActorSelection;import akka.actor.ActorSystem;import akka.actor.Props;import com.typesafe.config.ConfigFactory;public class ClientApp {static class ClientActor extends AbstractActor {private final String serverActorPath;public ClientActor(String serverActorPath) {this.serverActorPath = serverActorPath;}public void preStart() {ActorSelection serverActor = getContext().actorSelection(serverActorPath);serverActor.tell("Hello from Client", getSelf());}public Receive createReceive() {return receiveBuilder().match(String.class, msg -> {System.out.println("Client received message: " + msg);}).build();}}public static void main(String[] args) {ActorSystem system = ActorSystem.create("RemoteSystem", ConfigFactory.load("client"));String serverPath = "akka://RemoteSystem@127.0.0.1:2552/user/serverActor";ActorRef clientActor = system.actorOf(Props.create(ClientActor.class, serverPath), "clientActor");System.out.println("Client is running...");}}
以上只是一些关键代码，所有代码请参见下面代码仓库
代码仓库
https://github.com/Harries/springboot-demo(akka)
3.测试
启动server
启动client
产看日志
server
Server is running...Server received message: Hello from Client
client
Client is running...Client received message: Hello from Server
4.引用
https://doc.akka.io/docs/akka/current/remoting.html
https://doc.akka.io/docs/akka/current/remoting-artery.html#selecting-a-transport
http://www.liuhaihua.cn/archives/711361.html
原文作者：HBLOG；如有侵权，请联系管理员删除。
