[Dubbo] 多网卡问题

Dubbo启动时会获取设备网卡地址，可能会从设备上的以太网卡，虚拟网卡中选一个。

Dubbo源码

private URL buildUrl(ProtocolConfig protocolConfig, Map<String, String> params) {
        String name = protocolConfig.getName();
        if (StringUtils.isEmpty(name)) {
            name = "dubbo";
        }
        //获取host
        String host = findConfiguredHosts(protocolConfig, this.provider, params);
        //获取port
        Integer port = findConfiguredPort(protocolConfig, this.provider, this.getExtensionLoader(Protocol.class), name, params);
        URL url = new ServiceConfigURL(name, (String)null, (String)null, host, port, (String)this.getContextPath(protocolConfig).map((p) -> {
            return p + "/" + this.path;
        }).orElse(this.path), params);
        if (this.getExtensionLoader(ConfiguratorFactory.class).hasExtension(((URL)url).getProtocol())) {
            url = ((ConfiguratorFactory)this.getExtensionLoader(ConfiguratorFactory.class).getExtension(((URL)url).getProtocol())).getConfigurator((URL)url).configure((URL)url);
        }

        URL url = ((URL)url).setScopeModel(this.getScopeModel());
        url = url.setServiceModel(this.providerModel);
        return url;
    }

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获取host分别有三个源头 : host的获取顺序优先级分别是 protocolConfig >> provider >> 本地网卡地址

 1 private static String findConfiguredHosts(ProtocolConfig protocolConfig, ProviderConfig provider, Map<String, String> map) {
 2         boolean anyhost = false;
 3         //从系统环境变量去获取host ，key为DUBBO_IP_TO_BIND
 4         String hostToBind = getValueFromConfig(protocolConfig, "DUBBO_IP_TO_BIND");
 5         //注意这里 host不能为 127.0.0.1 和 localhost ，至于为什么不能为环回地址 此处不是很了解为啥这样设计？？？
 6         if (hostToBind != null && hostToBind.length() > 0 && NetUtils.isInvalidLocalHost(hostToBind)) {
 7             throw new IllegalArgumentException("Specified invalid bind ip from property:DUBBO_IP_TO_BIND, value:" + hostToBind);
 8         } else {
 9             // host的获取顺序优先级 分别是 protocolConfig >> provider >> 本地网卡地址
10             if (StringUtils.isEmpty(hostToBind)) {
11                 //protocolConfig 中获取
12                 hostToBind = protocolConfig.getHost();
13                 if (provider != null && StringUtils.isEmpty(hostToBind)) {
14                     //provider中获取
15                     hostToBind = provider.getHost();
16                 }
17 
18                 if (NetUtils.isInvalidLocalHost(hostToBind)) {
19                     anyhost = true;
20                     if (logger.isDebugEnabled()) {
21                         logger.info("No valid ip found from environment, try to get local host.");
22                     }
23                     //获取网卡ip
24                     hostToBind = NetUtils.getLocalHost();
25                 }
26             }
27 
28             map.put("bind.ip", hostToBind);
29             String hostToRegistry = getValueFromConfig(protocolConfig, "DUBBO_IP_TO_REGISTRY");
30             if (StringUtils.isNotEmpty(hostToRegistry) && NetUtils.isInvalidLocalHost(hostToRegistry)) {
31                 throw new IllegalArgumentException("Specified invalid registry ip from property:DUBBO_IP_TO_REGISTRY, value:" + hostToRegistry);
32             } else {
33                 if (StringUtils.isEmpty(hostToRegistry)) {
34                     hostToRegistry = hostToBind;
35                 }
36 
37                 map.put("anyhost", String.valueOf(anyhost));
38                 return hostToRegistry;
39             }
40         }
41     }

View Code

获取port也分别有三个源头 : 分别是 protocolConfig >> provider >> 扩展协议Protocol >> 本地随机可用 port

private static synchronized Integer findConfiguredPort(ProtocolConfig protocolConfig, ProviderConfig provider, ExtensionLoader<Protocol> extensionLoader, String name, Map<String, String> map) {
        String port = getValueFromConfig(protocolConfig, "DUBBO_PORT_TO_BIND");
        Integer portToBind = parsePort(port);
        if (portToBind == null) {
            portToBind = protocolConfig.getPort();
            if (provider != null && (portToBind == null || portToBind == 0)) {
                portToBind = provider.getPort();
            }
            
            //此处通过SPI可以扩展自定义的协议类型
            int defaultPort = ((Protocol)extensionLoader.getExtension(name)).getDefaultPort();
            if (portToBind == null || portToBind == 0) {
                portToBind = defaultPort;
            }
            
            //获取一个随机可用的port
            if (portToBind <= 0) {
                portToBind = getRandomPort(name);
                if (portToBind == null || portToBind < 0) {
                    portToBind = NetUtils.getAvailablePort(defaultPort);
                    putRandomPort(name, portToBind);
                }
            }
        }

        map.put("bind.port", String.valueOf(portToBind));
        String portToRegistryStr = getValueFromConfig(protocolConfig, "DUBBO_PORT_TO_REGISTRY");
        Integer portToRegistry = parsePort(portToRegistryStr);
        if (portToRegistry == null) {
            portToRegistry = portToBind;
        }

        return portToRegistry;
    }

View Code

解决方案：
通过对上面的源码分析，可以得出结论:

1.protocolConfig 我们可以通过配置设置 host和port信息。
xml配置文件方式
<dubbo:protocol name=“dubbo” port=“20880” host=“192.168.1.8” accesslog=“true”/>

SpringBoot 注入方式

2.provider 直接设置host，port 默认采用上面protocol设置的port。
xml配置文件方式
<dubbo:provider host=“192.168.1.8” protocol=“dubbo”/>

通过Api代码设置
ServiceConfig service = new ServiceConfig();否则可能造成内存和连接泄漏
service.setProtocol(protocol); // 多个协议可以用setProtocols()
service.setInterface(XxxService.class);
service.setRef(xxxService);
service.setVersion(“1.0.0”);

https://blog.csdn.net/z_Jimmy/article/details/126846473