java dubbo协议_dubbo协议端口

dubbo框架一共支持9种协议。其中，默认的，也是最常用的，那就是dubbo协议。

既然是协议，那么，就需要有端口。

所以，在使用dubbo协议暴露服务时，需要配置dubbo端口。

dubbo协议的默认端口是20880。

springboot配置：

dubbo:

application:

name: omsbase-provider

registry:

address: zookeeper://192.168.40.84:${embedded.zookeeper.port}

# address: zookeeper://127.0.0.1:2181

protocol:

name: dubbo

port:20888

一个应用程序启动后，dubbo即开启端口侦听请求。

linux服务器上查看dubbo端口：

[root@chuxing-service ~]# netstat -tunpl|grep 20880tcp60 0 :::20880 :::* LISTEN 16074/java

[root@chuxing-service ~]# netstat -tunpl|grep 2088*tcp60 0 :::20880 :::* LISTEN 16074/java

tcp60 0 :::20881 :::* LISTEN 15588/java

tcp60 0 :::20888 :::* LISTEN 6983/java

我们看看主进程应用：

[root@chuxing-service ~]# ps -ef|grep 16074root12630 11879 0 09:50 pts/1 00:00:00 grep –color=auto 16074root16074 1 0 Apr26 ? 00:04:31 java -Xms2g -Xmx4g -Djava.awt.headless=true -XX:MetaspaceSize=256m -XX:MaxMetaspaceSize=256m -server -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=85 -Xnoclassgc -Xverify:none -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -jar /www/service/car-pub-server-provider/bin/../car-pub-server-provider.jar

[root@chuxing-service ~]# ps -ef|grep 15588root12666 11879 0 09:50 pts/1 00:00:00 grep –color=auto 15588root15588 1 0 Apr26 ? 00:03:44 java -Xms2g -Xmx4g -Djava.awt.headless=true -XX:MetaspaceSize=256m -XX:MaxMetaspaceSize=256m -server -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=85 -Xnoclassgc -Xverify:none -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -jar /www/service/bosskg-server-provider/bin/../bosskg-server-provider.jar

netstat -apn/netstat -n

[root@chuxing-service ~]# netstat -apn |grep 20880tcp60 0 :::20880 :::* LISTEN 16074/java

tcp60 0 192.168.40.84:50120 192.168.40.84:20880 ESTABLISHED 10974/java

tcp60 0 192.168.40.84:20880 192.168.40.84:36100 ESTABLISHED 16074/java

tcp60 0 192.168.40.84:36104 192.168.40.84:20880 ESTABLISHED 6983/java

tcp60 0 192.168.40.84:20880 192.168.40.84:50120 ESTABLISHED 16074/java

tcp60 0 192.168.40.84:36100 192.168.40.84:20880 ESTABLISHED 7726/java

tcp60 0 192.168.40.84:20880 192.168.40.84:36104 ESTABLISHED 16074/java

[root@chuxing-service ~]# netstat -n |grep 20880tcp60 0 192.168.40.84:50120 192.168.40.84:20880ESTABLISHED

tcp60 0 192.168.40.84:20880 192.168.40.84:36100ESTABLISHED

tcp60 0 192.168.40.84:36104 192.168.40.84:20880ESTABLISHED

tcp60 0 192.168.40.84:20880 192.168.40.84:50120ESTABLISHED

tcp60 0 192.168.40.84:36100 192.168.40.84:20880ESTABLISHED

tcp60 0 192.168.40.84:20880 192.168.40.84:36104 ESTABLISHED

注意：因为端口不能重复，所以，当一台服务器有多个应用要暴露dubbo服务时，需要指定不同的协议端口。否则的话，程序起不来。

我们可以这样模拟：同一个使用了dubbo的应用程序，本地将其启动。此时，指定的端口将被占用。如果我们再运行一个testcase方法时，就会发现起不来了。异常信息：

2020-04-24 16:26:33.231 [main] ERROR org.springframework.boot.SpringApplication:858 -Application run failed

org.apache.dubbo.rpc.RpcException: Fail to start server(url: dubbo://10.8.0.58:20888/com.emax.omsbase.rpcapi.modules.enterprise.service.EnterpriseService?anyhost=true&application=omsbase-provider&bean.name=ServiceBean:com.emax.omsbase.rpcapi.modules.enterprise.service.EnterpriseService&bind.ip=10.8.0.58&bind.port=20888&channel.readonly.sent=true&codec=dubbo&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&heartbeat=60000&interface=com.emax.omsbase.rpcapi.modules.enterprise.service.EnterpriseService&methods=checkEnterprise,saveEnterprise,saveEnterpriseProductConfig,queryIndustryType1,getPage,selectLoginAcc,queryIndustryType2,updateEnterpriseById,updateEntStatusByEntId,resetEntAccountPasswordByEntId,openEnterpriseByEntId,updateEnterpriseProductConfigById,updateEnterpriseBillConfigById&pid=21060&qos.enable=false&register=true&release=2.7.3&side=provider&timeout=15000&timestamp=73) Failed to bind NettyServer on /10.8.0.58:20888, cause: Address already in use: bind

Caused by: org.apache.dubbo.remoting.RemotingException: Failed to bind NettyServer on/10.8.0.58:20888, cause: Address already in use: bind

Caused by: java.net.BindException: Address already in use: bind