rpc框架之gRPC 学习 - hello world

2023-08-19 22:11:04

grpc是google在github于2015年开源的一款RPC框架，虽然protobuf很早google就开源了，但是google一直没推出正式的开源框架，导致github上基于protobuf的rpc五花八门，国内比较著名的有百度的sofa-pbrpc，但是遗憾的是soft-pbrpc没有对应的java实现版本。rgpc还有一个独立的官网：http://www.grpc.io/，目前已经支持的语言有 C, C++, Java, Go, Node.js, Python, Ruby, Objective-C, PHP 、 C#. grpc最大的特点是基于protobuf + http2 协议，http2协议虽然还未正式定稿，但从目前得知的内容来看，潜力巨大。下面是grpc基本的hello world的示例：

一、grpc-contract

还是按老套路，把服务涉及的对象定义、接口定义抽象出来，下面是项目结构图：

pom.xml的内容如下：

 <?xml version="1.0" encoding="UTF-8"?>

 <project xmlns="http://maven.apache.org/POM/4.0.0"

          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>yjmyzz.grpc</groupId>

     <artifactId>grpc-contract</artifactId>

     <version>1.0</version>

     <dependencies>

         <dependency>

             <groupId>junit</groupId>

             <artifactId>junit</artifactId>

             <version>4.10</version>

         </dependency>

         <dependency>

             <groupId>com.google.protobuf</groupId>

             <artifactId>protobuf-java</artifactId>

             <version>3.0.0-beta-1</version>

         </dependency>

         <dependency>

             <groupId>io.grpc</groupId>

             <artifactId>grpc-all</artifactId>

             <version>0.8.0</version>

         </dependency>

     </dependencies>

     <!--下面这个节点可选-->

     <pluginRepositories>

         <pluginRepository>

             <releases>

                 <updatePolicy>never</updatePolicy>

             </releases>

             <snapshots>

                 <enabled>false</enabled>

             </snapshots>

             <id>central</id>

             <name>Central Repository</name>

             <url>https://repo.maven.apache.org/maven2</url>

         </pluginRepository>

         <pluginRepository>

             <id>protoc-plugin</id>

             <url>https://dl.bintray.com/sergei-ivanov/maven/</url>

         </pluginRepository>

     </pluginRepositories>

     <build>

         <extensions>

             <extension>

                 <groupId>kr.motd.maven</groupId>

                 <artifactId>os-maven-plugin</artifactId>

                 <version>1.4.0.Final</version>

             </extension>

         </extensions>

         <plugins>

             <!--用于根据proto文件生成java类的插件-->

             <plugin>

                 <groupId>com.google.protobuf.tools</groupId>

                 <artifactId>maven-protoc-plugin</artifactId>

                 <version>0.4.2</version>

                 <configuration>

                     <protocArtifact>com.google.protobuf:protoc:3.0.0-alpha-3.1:exe:${os.detected.classifier}

                     </protocArtifact>

                     <pluginId>grpc-java</pluginId>

                     <pluginArtifact>io.grpc:protoc-gen-grpc-java:0.8.0:exe:${os.detected.classifier}</pluginArtifact>

                 </configuration>

                 <executions>

                     <execution>

                         <goals>

                             <goal>compile</goal>

                             <goal>compile-custom</goal>

                         </goals>

                     </execution>

                 </executions>

             </plugin>

             <!--生成源代码jar包的插件（可选）-->

             <plugin>

                 <artifactId>maven-source-plugin</artifactId>

                 <version>2.4</version>

                 <executions>

                     <execution>

                         <phase>package</phase>

                         <goals>

                             <goal>jar-no-fork</goal>

                         </goals>

                     </execution>

                 </executions>

             </plugin>

         </plugins>

     </build>

 </project>

demo_service_dto.proto内容如下：

syntax = "proto3";

package yjmyzz.grpc.study.dto;

option java_multiple_files = true;

option java_outer_classname = "DemoServiceDto";

message PingRequest {

     string in=1;

}

message PingResponse {

     string out=1;

}

message QueryParameter {

     int32 ageStart = 1;

     int32 ageEnd = 2;

}

message Person {

     int32 age = 1;

     string name = 2;

     bool sex=3;

     double salary=4;

     int32 childrenCount=5;

}

message PersonList{

     repeated Person items=1;

}

注：grpc要求protobuf必须使用3.0以上版本

demo_service.proto内容如下：

syntax = "proto3";

import "demo_service_dto.proto";

package yjmyzz.grpc.study.service;

option java_multiple_files = true;

option java_outer_classname = "DemoServiceDto";

service DemoService {

    rpc Ping (yjmyzz.grpc.study.dto.PingRequest) returns (yjmyzz.grpc.study.dto.PingResponse) {}

    rpc getPersonList (yjmyzz.grpc.study.dto.QueryParameter) returns (yjmyzz.grpc.study.dto.PersonList) {}

}

mvn install 后，会自动在target下生成相应的java class类

二、grpc-server

pom.xml文件如下：

 <?xml version="1.0" encoding="UTF-8"?>

 <project xmlns="http://maven.apache.org/POM/4.0.0"

          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>yjmyzz.grpc</groupId>

     <artifactId>grpc-server</artifactId>

     <version>1.0</version>

     <dependencies>

         <dependency>

             <groupId>com.google.protobuf</groupId>

             <artifactId>protobuf-java</artifactId>

             <version>3.0.0-beta-1</version>

         </dependency>

         <dependency>

             <groupId>yjmyzz.grpc</groupId>

             <artifactId>grpc-contract</artifactId>

             <version>1.0</version>

         </dependency>

         <dependency>

             <groupId>io.grpc</groupId>

             <artifactId>grpc-all</artifactId>

             <version>0.8.0</version>

         </dependency>

         <dependency>

             <groupId>junit</groupId>

             <artifactId>junit</artifactId>

             <version>4.10</version>

         </dependency>

     </dependencies>

 </project>

先对服务接口提供实现：

package yjmyzz.grpc.study.service.impl;

import io.grpc.stub.StreamObserver;

import yjmyzz.grpc.study.dto.*;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import java.util.ArrayList;

import java.util.List;

public class DemoServiceImpl implements DemoServiceGrpc.DemoService {

    public void ping(PingRequest pingRequest, StreamObserver<PingResponse> streamObserver) {

        PingResponse reply = PingResponse.newBuilder().setOut("pong => " + pingRequest.getIn()).build();

        streamObserver.onValue(reply);

        streamObserver.onCompleted();

    }

    public void getPersonList(QueryParameter queryParameter, StreamObserver<PersonList> streamObserver) {

        //System.out.println(queryParameter.getAgeStart() + "-" + queryParameter.getAgeEnd());

        PersonList.Builder personListBuilder = PersonList.newBuilder();

        Person.Builder builder = Person.newBuilder();

        List<Person> list = new ArrayList<Person>();

        for (short i = 0; i < 10; i++) {

            list.add(builder.setAge(i).setChildrenCount(i).setName("test" + i).setSex(true).build());

        }

        personListBuilder.addAllItems(list);

        streamObserver.onValue(personListBuilder.build());

        streamObserver.onCompleted();

    }

}

和前面thrift、avro的helloworld一样，这里的实现只是意思一下，方便测试而已。

grpc的server端是基于Netty的（当然还有OKHttp的实现，详情见github项目主页），下面是server端的代码：

package yjmyzz.grpc.study.server;

import io.grpc.ServerImpl;

import io.grpc.inprocess.InProcessServerBuilder;

import io.grpc.netty.NettyServerBuilder;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import yjmyzz.grpc.study.service.impl.DemoServiceImpl;

public class DemoServiceServer {

    private int port = 50051;

    private ServerImpl server;

    private void start() throws Exception {

        server = NettyServerBuilder.forPort(port)

                .addService(DemoServiceGrpc.bindService(new DemoServiceImpl()))

                .build().start();

        server = InProcessServerBuilder.forName("testServer")

                .addService(DemoServiceGrpc.bindService(new DemoServiceImpl()))

                .build().start();

        System.out.println("Server started, listening on " + port);

        Runtime.getRuntime().addShutdownHook(new Thread() {

            @Override

            public void run() {

                System.out.println("*** shutting down gRPC server since JVM is shutting down");

                DemoServiceServer.this.stop();

                System.out.println("*** server shut down");

            }

        });

    }

    private void stop() {

        if (server != null) {

            server.shutdown();

        }

    }

    public static void main(String[] args) throws Exception {

        final DemoServiceServer server = new DemoServiceServer();

        server.start();

    }

}

三、grpc-client

pom.xml内容：

 <?xml version="1.0" encoding="UTF-8"?>

 <project xmlns="http://maven.apache.org/POM/4.0.0"

          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>yjmyzz.grpc</groupId>

     <artifactId>grpc-client</artifactId>

     <version>1.0</version>

     <dependencies>

         <dependency>

             <groupId>com.google.protobuf</groupId>

             <artifactId>protobuf-java</artifactId>

             <version>3.0.0-beta-1</version>

         </dependency>

         <dependency>

             <groupId>yjmyzz.grpc</groupId>

             <artifactId>grpc-contract</artifactId>

             <version>1.0</version>

         </dependency>

         <dependency>

             <groupId>io.grpc</groupId>

             <artifactId>grpc-all</artifactId>

             <version>0.8.0</version>

         </dependency>

         <dependency>

             <groupId>junit</groupId>

             <artifactId>junit</artifactId>

             <version>4.10</version>

         </dependency>

     </dependencies>

 </project>

Client端代码：

package yjmyzz.grpc.study.client;

import io.grpc.ChannelImpl;

import io.grpc.netty.NegotiationType;

import io.grpc.netty.NettyChannelBuilder;

import yjmyzz.grpc.study.dto.PersonList;

import yjmyzz.grpc.study.dto.PingRequest;

import yjmyzz.grpc.study.dto.PingResponse;

import yjmyzz.grpc.study.dto.QueryParameter;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import java.util.concurrent.TimeUnit;

public class DemoServiceClient {

    private final ChannelImpl channel;

    private final DemoServiceGrpc.DemoServiceBlockingStub blockingStub;

    public DemoServiceClient(String host, int port) {

        channel =

                NettyChannelBuilder.forAddress(host, port).negotiationType(NegotiationType.PLAINTEXT)

                        .build();

        blockingStub = DemoServiceGrpc.newBlockingStub(channel);

    }

    public void shutdown() throws InterruptedException {

        channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);

    }

    public void ping(String name) {

        try {

            System.out.println("Will try to ping " + name + " ...");

            PingRequest request = PingRequest.newBuilder().setIn(name).build();

            PingResponse response = blockingStub.ping(request);

            System.out.println("ping: " + response.getOut());

        } catch (RuntimeException e) {

            System.out.println("RPC failed:" + e.getMessage());

            return;

        }

    }

    public void getPersonList(QueryParameter parameter) {

        try {

            //System.out.println("Will try to getPersonList " + parameter + " ...");

            PersonList response = blockingStub.getPersonList(parameter);

            //System.out.println("items count: " + response.getItemsCount());

//            for (Person p : response.getItemsList()) {

//                System.out.println(p);

//            }

        } catch (RuntimeException e) {

            System.out.println("RPC failed:" + e.getMessage());

            return;

        }

    }

    public static void main(String[] args) throws Exception {

        DemoServiceClient client = new DemoServiceClient("localhost", 50051);

        try {

            client.ping("a");

            int max = 100000;

            Long start = System.currentTimeMillis();

            for (int i = 0; i < max; i++) {

                client.getPersonList(getParameter());

            }

            Long end = System.currentTimeMillis();

            Long elapse = end - start;

            int perform = Double.valueOf(max / (elapse / 1000d)).intValue();

            System.out.print("rgpc " + max + " 次NettyServer调用，耗时：" + elapse + "毫秒，平均" + perform + "次/秒");

        } finally {

            client.shutdown();

        }

    }

    private static QueryParameter getParameter() {

        return QueryParameter.newBuilder().setAgeStart(5).setAgeEnd(50).build();

    }

}

在笔记本测试的结果：

Will try to ping a ...
ping: pong => a
rgpc 100000 次NettyServer调用，耗时：36409毫秒，平均2746次/秒

基本上在每秒3k次的数量级，相对thrift（1w+）、avro(5k+)来讲，目前的差距还是很明显的，但是新事物成长总是需要时间，再给google一段时间，相信以后会让大家感到惊艳的。

在序列化方面，也做了一个跟之前thrift、avro类似的测试：

    @Test

    public void test() throws InvalidProtocolBufferException {

        QueryParameter queryParameter = QueryParameter.newBuilder().setAgeStart(1).setAgeEnd(5).build();

        byte[] bytes1 = queryParameter.toByteArray();

        System.out.println("Protobuf 3.0 二进制序列后的byte数组长度：" + bytes1.length);

        QueryParameter result = QueryParameter.parseFrom(bytes1);

        System.out.println(queryParameter.getAgeStart() + " - " + result.getAgeStart());

    }

输出：

Protobuf 3.0 二进制序列后的byte数组长度：4
1 - 1

在2进制序列化后的大小方面，protobuf 3大体跟thrift的TCompactProtocal（大小5）接近，比avro（大小2）略差。

文中示例源码下载：http://code.taobao.org/svn/grpc-demo/

参考文章：

RPC框架性能基本比较测试

Schema evolution in Avro, Protocol Buffers and Thrift

jvm-serializers

RPC综述 - PB, Thrift, Avro

码农公寓

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