(facebook) thrift / (hadoop) avro / (google) probuf（grpc）是近几年来比较抢眼的高效序列化/rpc框架，dubbo框架虽然有thrift的支持，但是依赖的版本较早，只支持0.8.0，而且还对协议做一些扩展，并非原生的thrift协议。
github上虽然也有朋友对dubbo做了扩展支持原生thrift，但是代码实在太多了，只需要一个类即可：
Thrift2Protocal.java:
package com.alibaba.dubbo.rpc.protocol.thrift2;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.rpc.RpcException;
import com.alibaba.dubbo.rpc.protocol.AbstractProxyProtocol;
import org.apache.thrift.TProcessor;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.server.TNonblockingServer;
import org.apache.thrift.server.TServer;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TNonblockingServerSocket;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import java.lang.reflect.Constructor;
/**
* 为dubbo-rpc添加"原生thrift"支持
* by 杨俊明(http://yjmyzz.cnblogs.com/)
*/
public class Thrift2Protocol extends AbstractProxyProtocol {
public static final int DEFAULT_PORT = 33208;
private static final Logger logger = LoggerFactory.getLogger(Thrift2Protocol.class);
public int getDefaultPort() {
return DEFAULT_PORT;
}
@Override
protected <T> Runnable doExport(T impl, Class<T> type, URL url)
throws RpcException {
logger.info("impl => " + impl.getClass());
logger.info("type => " + type.getName());
logger.info("url => " + url);
TProcessor tprocessor;
TNonblockingServer.Args tArgs = null;
String iFace = "$Iface";
String processor = "$Processor";
String typeName = type.getName();
TNonblockingServerSocket transport;
if (typeName.endsWith(iFace)) {
String processorClsName = typeName.substring(0, typeName.indexOf(iFace)) + processor;
try {
Class<?> clazz = Class.forName(processorClsName);
Constructor constructor = clazz.getConstructor(type);
try {
tprocessor = (TProcessor) constructor.newInstance(impl);
transport = new TNonblockingServerSocket(url.getPort());
tArgs = new TNonblockingServer.Args(transport);
tArgs.processor(tprocessor);
tArgs.transportFactory(new TFramedTransport.Factory());
tArgs.protocolFactory(new TCompactProtocol.Factory());
} catch (Exception e) {
logger.error(e.getMessage(), e);
throw new RpcException("Fail to create thrift server(" + url + ") : " + e.getMessage(), e);
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
throw new RpcException("Fail to create thrift server(" + url + ") : " + e.getMessage(), e);
}
}
if (tArgs == null) {
logger.error("Fail to create thrift server(" + url + ") due to null args");
throw new RpcException("Fail to create thrift server(" + url + ") due to null args");
}
final TServer thriftServer = new TNonblockingServer(tArgs);
new Thread(new Runnable() {
public void run() {
logger.info("Start Thrift Server");
thriftServer.serve();
logger.info("Thrift server started.");
}
}).start();
return new Runnable() {
public void run() {
try {
logger.info("Close Thrift Server");
thriftServer.stop();
} catch (Throwable e) {
logger.warn(e.getMessage(), e);
}
}
};
}
@Override
protected <T> T doRefer(Class<T> type, URL url) throws RpcException {
logger.info("type => " + type.getName());
logger.info("url => " + url);
try {
TSocket tSocket;
TTransport transport;
TProtocol protocol;
T thriftClient = null;
String iFace = "$Iface";
String client = "$Client";
String typeName = type.getName();
if (typeName.endsWith(iFace)) {
String clientClsName = typeName.substring(0, typeName.indexOf(iFace)) + client;
Class<?> clazz = Class.forName(clientClsName);
Constructor constructor = clazz.getConstructor(TProtocol.class);
try {
tSocket = new TSocket(url.getHost(), url.getPort());
transport = new TFramedTransport(tSocket);
protocol = new TCompactProtocol(transport);
thriftClient = (T) constructor.newInstance(protocol);
transport.open();
logger.info("thrift client opened for service(" + url + ")");
} catch (Exception e) {
logger.error(e.getMessage(), e);
throw new RpcException("Fail to create remoting client:" + e.getMessage(), e);
}
}
return thriftClient;
} catch (Exception e) {
logger.error(e.getMessage(), e);
throw new RpcException("Fail to create remoting client for service(" + url + "): " + e.getMessage(), e);
}
}
}
重写父类AbstractProxyProtocol的二个抽象方法doExport及doRefer即可，doExport用于对外暴露RPC服务，在这个方法里启动thrift server，dubbo service provider在启动时会调用该方法。而doRefer用于dubbo service consumer发现服务后，获取对应的rpc-client。
参考这个思路，avro也很容易集成进来：
AvroProtocol.java
package com.alibaba.dubbo.rpc.protocol.avro;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.rpc.RpcException;
import com.alibaba.dubbo.rpc.protocol.AbstractProxyProtocol;
import org.apache.avro.ipc.NettyServer;
import org.apache.avro.ipc.NettyTransceiver;
import org.apache.avro.ipc.Server;
import org.apache.avro.ipc.reflect.ReflectRequestor;
import org.apache.avro.ipc.reflect.ReflectResponder;
import java.net.InetSocketAddress;
/**
* 为dubbo-rpc添加avro支持
* by 杨俊明(http://yjmyzz.cnblogs.com/)
*/
public class AvroProtocol extends AbstractProxyProtocol {
public static final int DEFAULT_PORT = 40881;
private static final Logger logger = LoggerFactory.getLogger(AvroProtocol.class);
public int getDefaultPort() {
return DEFAULT_PORT;
}
@Override
protected <T> Runnable doExport(T impl, Class<T> type, URL url)
throws RpcException {
logger.info("impl => " + impl.getClass());
logger.info("type => " + type.getName());
logger.info("url => " + url);
final Server server = new NettyServer(new ReflectResponder(type, impl),
new InetSocketAddress(url.getHost(), url.getPort()));
server.start();
return new Runnable() {
public void run() {
try {
logger.info("Close Avro Server");
server.close();
} catch (Throwable e) {
logger.warn(e.getMessage(), e);
}
}
};
}
@Override
protected <T> T doRefer(Class<T> type, URL url) throws RpcException {
logger.info("type => " + type.getName());
logger.info("url => " + url);
try {
NettyTransceiver client = new NettyTransceiver(new InetSocketAddress(url.getHost(), url.getPort()));
T ref = ReflectRequestor.getClient(type, client);
logger.info("Create Avro Client");
return ref;
} catch (Exception e) {
logger.error(e.getMessage(), e);
throw new RpcException("Fail to create remoting client for service(" + url + "): " + e.getMessage(), e);
}
}
}
不要忘记在META-INF/dubbo/internal下添加名为com.alibaba.dubbo.rpc.Protocal的文件，内容为：
avro=com.alibaba.dubbo.rpc.protocol.avro.AvroProtocol
接下来谈谈如何打包到dubbo的jar里：
dubbo-rpc/pom.xml里，把二个新增的项目加进来：
<modules> ... <module>dubbo-rpc-avro</module> ... <module>dubbo-rpc-thrift2</module> ... </modules>
然后dubbo/pom.xml里：
<artifactSet> <includes> ... <include>com.alibaba:dubbo-rpc-api</include> <include>com.alibaba:dubbo-rpc-avro</include> ... <include>com.alibaba:dubbo-rpc-thrift2</include> ... </includes> </artifactSet>
dependencies节也要增加：
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo-rpc-thrift2</artifactId>
<version>${project.parent.version}</version>
<exclusions>
<exclusion>
<groupId>org.apache.thrift</groupId>
<artifactId>libthrift</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo-rpc-avro</artifactId>
<version>${project.parent.version}</version>
<exclusions>
<exclusion>
<groupId>org.apache.avro</groupId>
<artifactId>avro</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.avro</groupId>
<artifactId>avro-ipc</artifactId>
</exclusion>
</exclusions>
</dependency>
这样打包出来的dubbo-xxx.jar里，就包括新增的Protocol。至于google的protobuf，目前处于3.x -beta阶段，等以后出正式版了，再看情况整合起来。
以上代码已经提交到github:https://github.com/yjmyzz/dubbox （版本号：2.8.4a）
thrift/avro协议的使用示例见:https://github.com/yjmyzz/dubbox-sample
最后，对dubbo/thrift/avro/rest这4种协议，做了下简单的对比测试，测试用例很简单：
public String ping() {
return "pong";
}
客户端调用ping方法，服务器返回字符串"pong"，在mac book pro上做5万次调用，结果如下：
dubbo RPC testing => 50000次RPC调用(dubbo协议),共耗时14778毫秒,平均3383.407715/秒 avro RPC testing => 50000次RPC调用(avro协议),共耗时10707毫秒,平均4669.842285/秒 thrift RPC testing => 50000次RPC调用(thrift协议),共耗时4667毫秒,平均10713.520508/秒 REST testing => 50000次REST调用,共耗时112699毫秒,平均443.659668/秒
这跟预期一致，REST走http协议，自然最慢，avro与dubbo底层的网络通讯都是借助netty实现，在同一个数量级，但是avro的二进制序列化效率更高，所以略快，而thrift则是从里到外，全都是facebook自己实现的，性能最优，完胜其它协议。
个人建议：对于一个服务接口，对外同时提供thrift、REST二种形式的服务实现，内部子系统之间用thrift方式调用(因为thrift跨语言，其实从外部进来的调用，也可以用thrift-rpc方式)，一些不方便直接用thrift-client调用的场景，仍然走传统的REST.
