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:
akka-remoting" height="606" src="https://img-blog.csdnimg.cn/img_convert/980fd5f18faab1b12b3f25e9c9c44ac2.png" width="632" />
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;}@Overridepublic void preStart() {ActorSelection serverActor = getContext().actorSelection(serverActorPath);serverActor.tell("Hello from Client", getSelf());}@Overridepublic 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
- GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.(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