关于java:阿里终面如何设计一个高性能网关

作者：烟味 i \
链接：https://cnblogs.com/2YSP/p/14…

一、前言

最近在 github 上看了 soul 网关的设计，忽然就来了趣味筹备本人从零开始写一个高性能的网关。

通过两周工夫的开发，我的网关 ship-gate 外围性能根本都已实现，最大的缺点就是前端功底太差没有治理后盾😤。

二、设计

2.1 技术选型

网关是所有申请的入口，所以要求有很高的吞吐量，为了实现这点能够应用申请异步化来解决。

目前个别有以下两种计划：

• Tomcat/Jetty+NIO+Servlet3

Servlet3 曾经反对异步，这种计划应用比拟多，京东，有赞和 Zuul，都用的是这种计划。

• Netty+NIO

Netty 为高并发而生，目前唯品会的网关应用这个策略，在唯品会的技术文章中在雷同的状况下 Netty 是每秒 30w+ 的吞吐量，Tomcat 是 13w+, 能够看出是有肯定的差距的，然而 Netty 须要本人解决 HTTP 协定，这一块比拟麻烦。

前面发现 Soul 网关是基于 Spring WebFlux（底层 Netty）的，不必太关怀 HTTP 协定的解决，于是决定也用 Spring WebFlux。

网关的第二个特点是具备可扩展性，比方 Netflix Zuul 有 preFilters，postFilters 等在不同的阶段不便解决不同的业务，基于责任链模式将申请进行链式解决即可实现。

在微服务架构下，服务都会进行多实例部署来保障高可用，申请达到网关时，网关须要依据 URL 找到所有可用的实例，这时就须要服务注册和发现性能，即注册核心。

当初风行的注册核心有 Apache 的 Zookeeper 和阿里的 Nacos 两种（consul 有点小众），因为之前写 RPC 框架时曾经用过了 Zookeeper，所以这次就抉择了 Nacos。

2.2 需要清单

首先要明确指标，即开发一个具备哪些个性的网关，总结下后如下：

• 自定义路由规定

  可基于 version 的路由规定设置，路由对象包含 DEFAUL,HEADER 和 QUERY 三种，匹配形式包含 =、regex、like 三种。

• 跨语言

  HTTP 协定天生跨语言

• 高性能

  Netty 自身就是一款高性能的通信框架，同时 server 将一些路由规定等数据缓存到 JVM 内存防止申请 admin 服务。

• 高可用

  反对集群模式避免单节点故障，无状态。

• 灰度公布

  灰度公布（又名金丝雀公布）是指在黑与白之间，可能平滑过渡的一种公布形式。在其上能够进行 A /B testing，即让一部分用户持续用产品个性 A，一部分用户开始用产品个性 B，如果用户对 B 没有什么拥护意见，那么逐渐扩大范围，把所有用户都迁徙到 B 下面来。通过个性一能够实现。

• 接口鉴权

  基于责任链模式，用户开发本人的鉴权插件即可。

• 负载平衡

  反对多种负载平衡算法，如随机，轮询，加权轮询等。利用 SPI 机制能够依据配置进行动静加载。

2.3 架构设计

在参考了一些优良的网关 Zuul,Spring Cloud Gateway,Soul 后，将我的项目划分为以下几个模块。

它们之间的关系如图：

留神： 这张图与理论实现有点出入，Nacos push 到本地缓存的那个环节没有实现，目前只有 ship-sever 定时轮询 pull 的过程。ship-admin 从 Nacos 获取注册服务信息的过程，也改成了 ServiceA 启动时被动产生 HTTP 申请告诉 ship-admin。

2.4 表结构设计

三、编码

3.1 ship-client-spring-boot-starter

首先创立一个 spring-boot-starter 命名为 ship-client-spring-boot-starter，不晓得如何自定义 starter 的能够看我以前写的《开发本人的 starter》。

更多 Spring Boot 教程举荐看这个：

https://github.com/javastacks…

其外围类 AutoRegisterListener 就是在我的项目启动时做了两件事：

1. 将服务信息注册到 Nacos 注册核心

2. 告诉 ship-admin 服务上线了并注册下线 hook。

代码如下：

/**
 * Created by 2YSP on 2020/12/21
 */
public class AutoRegisterListener implements ApplicationListener<ContextRefreshedEvent> {private final static Logger LOGGER = LoggerFactory.getLogger(AutoRegisterListener.class);
 
    private volatile AtomicBoolean registered = new AtomicBoolean(false);
 
    private final ClientConfigProperties properties;
 
    @NacosInjected
    private NamingService namingService;
 
    @Autowired
    private RequestMappingHandlerMapping handlerMapping;
 
    private final ExecutorService pool;
 
    /**
     * url list to ignore
     */
    private static List<String> ignoreUrlList = new LinkedList<>();
 
    static {ignoreUrlList.add("/error");
    }
 
    public AutoRegisterListener(ClientConfigProperties properties) {if (!check(properties)) {LOGGER.error("client config port,contextPath,appName adminUrl and version can't be empty!");
            throw new ShipException("client config port,contextPath,appName adminUrl and version can't be empty!");
        }
        this.properties = properties;
        pool = new ThreadPoolExecutor(1, 4, 0, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
    }
 
    /**
     * check the ClientConfigProperties
     *
     * @param properties
     * @return
     */
    private boolean check(ClientConfigProperties properties) {if (properties.getPort() == null || properties.getContextPath() == null
                || properties.getVersion() == null || properties.getAppName() == null
                || properties.getAdminUrl() == null) {return false;}
        return true;
    }
 
 
    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {if (!registered.compareAndSet(false, true)) {return;}
        doRegister();
        registerShutDownHook();}
 
    /**
     * send unregister request to admin when jvm shutdown
     */
    private void registerShutDownHook() {final String url = "http://" + properties.getAdminUrl() + AdminConstants.UNREGISTER_PATH;
        final UnregisterAppDTO unregisterAppDTO = new UnregisterAppDTO();
        unregisterAppDTO.setAppName(properties.getAppName());
        unregisterAppDTO.setVersion(properties.getVersion());
        unregisterAppDTO.setIp(IpUtil.getLocalIpAddress());
        unregisterAppDTO.setPort(properties.getPort());
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {OkhttpTool.doPost(url, unregisterAppDTO);
            LOGGER.info("[{}:{}] unregister from ship-admin success!", unregisterAppDTO.getAppName(), unregisterAppDTO.getVersion());
        }));
    }
 
    /**
     * register all interface info to register center
     */
    private void doRegister() {Instance instance = new Instance();
        instance.setIp(IpUtil.getLocalIpAddress());
        instance.setPort(properties.getPort());
        instance.setEphemeral(true);
        Map<String, String> metadataMap = new HashMap<>();
        metadataMap.put("version", properties.getVersion());
        metadataMap.put("appName", properties.getAppName());
        instance.setMetadata(metadataMap);
        try {namingService.registerInstance(properties.getAppName(), NacosConstants.APP_GROUP_NAME, instance);
        } catch (NacosException e) {LOGGER.error("register to nacos fail", e);
            throw new ShipException(e.getErrCode(), e.getErrMsg());
        }
        LOGGER.info("register interface info to nacos success!");
        // send register request to ship-admin
        String url = "http://" + properties.getAdminUrl() + AdminConstants.REGISTER_PATH;
        RegisterAppDTO registerAppDTO = buildRegisterAppDTO(instance);
        OkhttpTool.doPost(url, registerAppDTO);
        LOGGER.info("register to ship-admin success!");
    }
 
 
    private RegisterAppDTO buildRegisterAppDTO(Instance instance) {RegisterAppDTO registerAppDTO = new RegisterAppDTO();
        registerAppDTO.setAppName(properties.getAppName());
        registerAppDTO.setContextPath(properties.getContextPath());
        registerAppDTO.setIp(instance.getIp());
        registerAppDTO.setPort(instance.getPort());
        registerAppDTO.setVersion(properties.getVersion());
        return registerAppDTO;
    }
}
 

3.2 ship-server

ship-sever 我的项目次要包含了两个局部内容：

1. 申请动静路由的主流程

2. 本地缓存数据和 ship-admin 及 nacos 同步，这部分在前面 3.3 再讲。

ship-server 实现动静路由的原理是利用 WebFilter 拦挡申请，而后将申请教给 plugin chain 去链式解决。

PluginFilter 依据 URL 解析出 appName，而后将启用的 plugin 组装成 plugin chain。

public class PluginFilter implements WebFilter {
 
    private ServerConfigProperties properties;
 
    public PluginFilter(ServerConfigProperties properties) {this.properties = properties;}
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {String appName = parseAppName(exchange);
        if (CollectionUtils.isEmpty(ServiceCache.getAllInstances(appName))) {throw new ShipException(ShipExceptionEnum.SERVICE_NOT_FIND);
        }
        PluginChain pluginChain = new PluginChain(properties, appName);
        pluginChain.addPlugin(new DynamicRoutePlugin(properties));
        pluginChain.addPlugin(new AuthPlugin(properties));
        return pluginChain.execute(exchange, pluginChain);
    }
 
    private String parseAppName(ServerWebExchange exchange) {RequestPath path = exchange.getRequest().getPath();
        String appName = path.value().split("/")[1];
        return appName;
    }
}

PluginChain 继承了 AbstractShipPlugin 并持有所有要执行的插件。

/**
 * @Author: Ship
 * @Description:
 * @Date: Created in 2020/12/25
 */
public class PluginChain extends AbstractShipPlugin {
    /**
     * the pos point to current plugin
     */
    private int pos;
    /**
     * the plugins of chain
     */
    private List<ShipPlugin> plugins;
 
    private final String appName;
 
    public PluginChain(ServerConfigProperties properties, String appName) {super(properties);
        this.appName = appName;
    }
 
    /**
     * add enabled plugin to chain
     *
     * @param shipPlugin
     */
    public void addPlugin(ShipPlugin shipPlugin) {if (plugins == null) {plugins = new ArrayList<>();
        }
        if (!PluginCache.isEnabled(appName, shipPlugin.name())) {return;}
        plugins.add(shipPlugin);
        // order by the plugin's order
        plugins.sort(Comparator.comparing(ShipPlugin::order));
    }
 
    @Override
    public Integer order() {return null;}
 
    @Override
    public String name() {return null;}
 
    @Override
    public Mono<Void> execute(ServerWebExchange exchange, PluginChain pluginChain) {if (pos == plugins.size()) {return exchange.getResponse().setComplete();}
        return pluginChain.plugins.get(pos++).execute(exchange, pluginChain);
    }
 
    public String getAppName() {return appName;}
 
}
 

AbstractShipPlugin 实现了 ShipPlugin 接口，并持有 ServerConfigProperties 配置对象。

public abstract class AbstractShipPlugin implements ShipPlugin {
 
    protected ServerConfigProperties properties;
 
    public AbstractShipPlugin(ServerConfigProperties properties) {this.properties = properties;}
}

ShipPlugin 接口定义了所有插件必须实现的三个办法 order(),name() 和 execute()。

public interface ShipPlugin {
    /**
     * lower values have higher priority
     *
     * @return
     */
    Integer order();
 
    /**
     * return current plugin name
     *
     * @return
     */
    String name();
 
    Mono<Void> execute(ServerWebExchange exchange,PluginChain pluginChain);
 
}

DynamicRoutePlugin 继承了抽象类 AbstractShipPlugin，蕴含了动静路由的次要业务逻辑。

/**
 * @Author: Ship
 * @Description:
 * @Date: Created in 2020/12/25
 */
public class DynamicRoutePlugin extends AbstractShipPlugin {private final static Logger LOGGER = LoggerFactory.getLogger(DynamicRoutePlugin.class);
 
    private static WebClient webClient;
 
    private static final Gson gson = new GsonBuilder().create();
 
    static {HttpClient httpClient = HttpClient.create()
                .tcpConfiguration(client ->
                        client.doOnConnected(conn ->
                                conn.addHandlerLast(new ReadTimeoutHandler(3))
                                        .addHandlerLast(new WriteTimeoutHandler(3)))
                                .option(ChannelOption.TCP_NODELAY, true)
                );
        webClient = WebClient.builder().clientConnector(new ReactorClientHttpConnector(httpClient))
                .build();}
 
    public DynamicRoutePlugin(ServerConfigProperties properties) {super(properties);
    }
 
    @Override
    public Integer order() {return ShipPluginEnum.DYNAMIC_ROUTE.getOrder();
    }
 
    @Override
    public String name() {return ShipPluginEnum.DYNAMIC_ROUTE.getName();
    }
 
    @Override
    public Mono<Void> execute(ServerWebExchange exchange, PluginChain pluginChain) {String appName = pluginChain.getAppName();
        ServiceInstance serviceInstance = chooseInstance(appName, exchange.getRequest());
//        LOGGER.info("selected instance is [{}]", gson.toJson(serviceInstance));
        // request service
        String url = buildUrl(exchange, serviceInstance);
        return forward(exchange, url);
    }
 
    /**
     * forward request to backend service
     *
     * @param exchange
     * @param url
     * @return
     */
    private Mono<Void> forward(ServerWebExchange exchange, String url) {ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        HttpMethod method = request.getMethod();
 
        WebClient.RequestBodySpec requestBodySpec = webClient.method(method).uri(url).headers((headers) -> {headers.addAll(request.getHeaders());
        });
 
        WebClient.RequestHeadersSpec<?> reqHeadersSpec;
        if (requireHttpBody(method)) {reqHeadersSpec = requestBodySpec.body(BodyInserters.fromDataBuffers(request.getBody()));
        } else {reqHeadersSpec = requestBodySpec;}
        // nio->callback->nio
        return reqHeadersSpec.exchange().timeout(Duration.ofMillis(properties.getTimeOutMillis()))
                .onErrorResume(ex -> {return Mono.defer(() -> {
                        String errorResultJson = "";
                        if (ex instanceof TimeoutException) {errorResultJson = "{\"code\":5001,\"message\":\"network timeout\"}";
                        } else {errorResultJson = "{\"code\":5000,\"message\":\"system error\"}";
                        }
                        return ShipResponseUtil.doResponse(exchange, errorResultJson);
                    }).then(Mono.empty());
                }).flatMap(backendResponse -> {response.setStatusCode(backendResponse.statusCode());
                    response.getHeaders().putAll(backendResponse.headers().asHttpHeaders());
                    return response.writeWith(backendResponse.bodyToFlux(DataBuffer.class));
                });
    }
 
    /**
     * weather the http method need http body
     *
     * @param method
     * @return
     */
    private boolean requireHttpBody(HttpMethod method) {if (method.equals(HttpMethod.POST) || method.equals(HttpMethod.PUT) || method.equals(HttpMethod.PATCH)) {return true;}
        return false;
    }
 
    private String buildUrl(ServerWebExchange exchange, ServiceInstance serviceInstance) {ServerHttpRequest request = exchange.getRequest();
        String query = request.getURI().getQuery();
        String path = request.getPath().value().replaceFirst("/" + serviceInstance.getAppName(), "");
        String url = "http://" + serviceInstance.getIp() + ":" + serviceInstance.getPort() + path;
        if (!StringUtils.isEmpty(query)) {url = url + "?" + query;}
        return url;
    }
 
 
    /**
     * choose an ServiceInstance according to route rule config and load balancing algorithm
     *
     * @param appName
     * @param request
     * @return
     */
    private ServiceInstance chooseInstance(String appName, ServerHttpRequest request) {List<ServiceInstance> serviceInstances = ServiceCache.getAllInstances(appName);
        if (CollectionUtils.isEmpty(serviceInstances)) {LOGGER.error("service instance of {} not find", appName);
            throw new ShipException(ShipExceptionEnum.SERVICE_NOT_FIND);
        }
        String version = matchAppVersion(appName, request);
        if (StringUtils.isEmpty(version)) {throw new ShipException("match app version error");
        }
        // filter serviceInstances by version
        List<ServiceInstance> instances = serviceInstances.stream().filter(i -> i.getVersion().equals(version)).collect(Collectors.toList());
        //Select an instance based on the load balancing algorithm
        LoadBalance loadBalance = LoadBalanceFactory.getInstance(properties.getLoadBalance(), appName, version);
        ServiceInstance serviceInstance = loadBalance.chooseOne(instances);
        return serviceInstance;
    }
 
 
    private String matchAppVersion(String appName, ServerHttpRequest request) {List<AppRuleDTO> rules = RouteRuleCache.getRules(appName);
        rules.sort(Comparator.comparing(AppRuleDTO::getPriority).reversed());
        for (AppRuleDTO rule : rules) {if (match(rule, request)) {return rule.getVersion();
            }
        }
        return null;
    }
 
 
    private boolean match(AppRuleDTO rule, ServerHttpRequest request) {String matchObject = rule.getMatchObject();
        String matchKey = rule.getMatchKey();
        String matchRule = rule.getMatchRule();
        Byte matchMethod = rule.getMatchMethod();
        if (MatchObjectEnum.DEFAULT.getCode().equals(matchObject)) {return true;} else if (MatchObjectEnum.QUERY.getCode().equals(matchObject)) {String param = request.getQueryParams().getFirst(matchKey);
            if (!StringUtils.isEmpty(param)) {return StringTools.match(param, matchMethod, matchRule);
            }
        } else if (MatchObjectEnum.HEADER.getCode().equals(matchObject)) {HttpHeaders headers = request.getHeaders();
            String headerValue = headers.getFirst(matchKey);
            if (!StringUtils.isEmpty(headerValue)) {return StringTools.match(headerValue, matchMethod, matchRule);
            }
        }
        return false;
    }
 
}
 

3.3 数据同步

app 数据同步

后盾服务（如订单服务）启动时，只将服务名，版本，ip 地址和端口号注册到了 Nacos，并没有实例的权重和启用的插件信息怎么办？

个别在线的实例权重和插件列表都是在治理界面配置，而后动静失效的，所以须要 ship-admin 定时更新实例的权重和插件信息到注册核心。

对应代码 ship-admin 的 NacosSyncListener

/**
 * @Author: Ship
 * @Description:
 * @Date: Created in 2020/12/30
 */
@Configuration
public class NacosSyncListener implements ApplicationListener<ContextRefreshedEvent> {private static final Logger LOGGER = LoggerFactory.getLogger(NacosSyncListener.class);
 
    private static ScheduledThreadPoolExecutor scheduledPool = new ScheduledThreadPoolExecutor(1,
            new ShipThreadFactory("nacos-sync", true).create());
 
    @NacosInjected
    private NamingService namingService;
 
    @Value("${nacos.discovery.server-addr}")
    private String baseUrl;
 
    @Resource
    private AppService appService;
 
    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {if (event.getApplicationContext().getParent() != null) {return;}
        String url = "http://" + baseUrl + NacosConstants.INSTANCE_UPDATE_PATH;
        scheduledPool.scheduleWithFixedDelay(new NacosSyncTask(namingService, url, appService), 0, 30L, TimeUnit.SECONDS);
    }
 
    class NacosSyncTask implements Runnable {
 
        private NamingService namingService;
 
        private String url;
 
        private AppService appService;
 
        private Gson gson = new GsonBuilder().create();
 
        public NacosSyncTask(NamingService namingService, String url, AppService appService) {
            this.namingService = namingService;
            this.url = url;
            this.appService = appService;
        }
 
        /**
         * Regular update weight,enabled plugins to nacos instance
         */
        @Override
        public void run() {
            try {
                // get all app names
                ListView<String> services = namingService.getServicesOfServer(1, Integer.MAX_VALUE, NacosConstants.APP_GROUP_NAME);
                if (CollectionUtils.isEmpty(services.getData())) {return;}
                List<String> appNames = services.getData();
                List<AppInfoDTO> appInfos = appService.getAppInfos(appNames);
                for (AppInfoDTO appInfo : appInfos) {if (CollectionUtils.isEmpty(appInfo.getInstances())) {continue;}
                    for (ServiceInstance instance : appInfo.getInstances()) {Map<String, Object> queryMap = buildQueryMap(appInfo, instance);
                        String resp = OkhttpTool.doPut(url, queryMap, "");
                        LOGGER.debug("response :{}", resp);
                    }
                }
 
            } catch (Exception e) {LOGGER.error("nacos sync task error", e);
            }
        }
 
        private Map<String, Object> buildQueryMap(AppInfoDTO appInfo, ServiceInstance instance) {Map<String, Object> map = new HashMap<>();
            map.put("serviceName", appInfo.getAppName());
            map.put("groupName", NacosConstants.APP_GROUP_NAME);
            map.put("ip", instance.getIp());
            map.put("port", instance.getPort());
            map.put("weight", instance.getWeight().doubleValue());
            NacosMetadata metadata = new NacosMetadata();
            metadata.setAppName(appInfo.getAppName());
            metadata.setVersion(instance.getVersion());
            metadata.setPlugins(String.join(",", appInfo.getEnabledPlugins()));
            map.put("metadata", StringTools.urlEncode(gson.toJson(metadata)));
            map.put("ephemeral", true);
            return map;
        }
    }
}
 

ship-server 再定时从 Nacos 拉取 app 数据更新到本地 Map 缓存。

/**
 * @Author: Ship
 * @Description: sync data to local cache
 * @Date: Created in 2020/12/25
 */
@Configuration
public class DataSyncTaskListener implements ApplicationListener<ContextRefreshedEvent> {
 
    private static ScheduledThreadPoolExecutor scheduledPool = new ScheduledThreadPoolExecutor(1,
            new ShipThreadFactory("service-sync", true).create());
 
    @NacosInjected
    private NamingService namingService;
 
    @Autowired
    private ServerConfigProperties properties;
 
    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {if (event.getApplicationContext().getParent() != null) {return;}
        scheduledPool.scheduleWithFixedDelay(new DataSyncTask(namingService)
                , 0L, properties.getCacheRefreshInterval(), TimeUnit.SECONDS);
        WebsocketSyncCacheServer websocketSyncCacheServer = new WebsocketSyncCacheServer(properties.getWebSocketPort());
        websocketSyncCacheServer.start();}
 
 
    class DataSyncTask implements Runnable {
 
        private NamingService namingService;
 
        public DataSyncTask(NamingService namingService) {this.namingService = namingService;}
 
        @Override
        public void run() {
            try {
                // get all app names
                ListView<String> services = namingService.getServicesOfServer(1, Integer.MAX_VALUE, NacosConstants.APP_GROUP_NAME);
                if (CollectionUtils.isEmpty(services.getData())) {return;}
                List<String> appNames = services.getData();
                // get all instances
                for (String appName : appNames) {List<Instance> instanceList = namingService.getAllInstances(appName, NacosConstants.APP_GROUP_NAME);
                    if (CollectionUtils.isEmpty(instanceList)) {continue;}
                    ServiceCache.add(appName, buildServiceInstances(instanceList));
                    List<String> pluginNames = getEnabledPlugins(instanceList);
                    PluginCache.add(appName, pluginNames);
                }
                ServiceCache.removeExpired(appNames);
                PluginCache.removeExpired(appNames);
 
            } catch (NacosException e) {e.printStackTrace();
            }
        }
 
        private List<String> getEnabledPlugins(List<Instance> instanceList) {Instance instance = instanceList.get(0);
            Map<String, String> metadata = instance.getMetadata();
            // plugins: DynamicRoute,Auth
            String plugins = metadata.getOrDefault("plugins", ShipPluginEnum.DYNAMIC_ROUTE.getName());
            return Arrays.stream(plugins.split(",")).collect(Collectors.toList());
        }
 
        private List<ServiceInstance> buildServiceInstances(List<Instance> instanceList) {List<ServiceInstance> list = new LinkedList<>();
            instanceList.forEach(instance -> {Map<String, String> metadata = instance.getMetadata();
                ServiceInstance serviceInstance = new ServiceInstance();
                serviceInstance.setAppName(metadata.get("appName"));
                serviceInstance.setIp(instance.getIp());
                serviceInstance.setPort(instance.getPort());
                serviceInstance.setVersion(metadata.get("version"));
                serviceInstance.setWeight((int) instance.getWeight());
                list.add(serviceInstance);
            });
            return list;
        }
    }
}
 

路由规定数据同步

同时，如果用户在治理后盾更新了路由规定，ship-admin 须要推送规定数据到 ship-server，这里参考了 soul 网关的做法利用 websocket 在第一次建设连贯后进行全量同步，尔后路由规定产生变更就只作增量同步。

服务端 WebsocketSyncCacheServer：

/**
 * @Author: Ship
 * @Description:
 * @Date: Created in 2020/12/28
 */
public class WebsocketSyncCacheServer extends WebSocketServer {private final static Logger LOGGER = LoggerFactory.getLogger(WebsocketSyncCacheServer.class);
 
    private Gson gson = new GsonBuilder().create();
 
    private MessageHandler messageHandler;
 
    public WebsocketSyncCacheServer(Integer port) {super(new InetSocketAddress(port));
        this.messageHandler = new MessageHandler();}
 
 
    @Override
    public void onOpen(WebSocket webSocket, ClientHandshake clientHandshake) {LOGGER.info("server is open");
    }
 
    @Override
    public void onClose(WebSocket webSocket, int i, String s, boolean b) {LOGGER.info("websocket server close...");
    }
 
    @Override
    public void onMessage(WebSocket webSocket, String message) {LOGGER.info("websocket server receive message:\n[{}]", message);
        this.messageHandler.handler(message);
    }
 
    @Override
    public void onError(WebSocket webSocket, Exception e) { }
 
    @Override
    public void onStart() {LOGGER.info("websocket server start...");
    }
 
 
    class MessageHandler {public void handler(String message) {RouteRuleOperationDTO operationDTO = gson.fromJson(message, RouteRuleOperationDTO.class);
            if (CollectionUtils.isEmpty(operationDTO.getRuleList())) {return;}
            Map<String, List<AppRuleDTO>> map = operationDTO.getRuleList()
                    .stream().collect(Collectors.groupingBy(AppRuleDTO::getAppName));
            if (OperationTypeEnum.INSERT.getCode().equals(operationDTO.getOperationType())
                    || OperationTypeEnum.UPDATE.getCode().equals(operationDTO.getOperationType())) {RouteRuleCache.add(map);
            } else if (OperationTypeEnum.DELETE.getCode().equals(operationDTO.getOperationType())) {RouteRuleCache.remove(map);
            }
        }
    }
}
 

客户端 WebsocketSyncCacheClient：

/**
 * @Author: Ship
 * @Description:
 * @Date: Created in 2020/12/28
 */
@Component
public class WebsocketSyncCacheClient {private final static Logger LOGGER = LoggerFactory.getLogger(WebsocketSyncCacheClient.class);
 
    private WebSocketClient client;
 
    private RuleService ruleService;
 
    private Gson gson = new GsonBuilder().create();
 
    public WebsocketSyncCacheClient(@Value("${ship.server-web-socket-url}") String serverWebSocketUrl,
                                    RuleService ruleService) {if (StringUtils.isEmpty(serverWebSocketUrl)) {throw new ShipException(ShipExceptionEnum.CONFIG_ERROR);
        }
        this.ruleService = ruleService;
        ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(1,
                new ShipThreadFactory("websocket-connect", true).create());
        try {client = new WebSocketClient(new URI(serverWebSocketUrl)) {
                @Override
                public void onOpen(ServerHandshake serverHandshake) {LOGGER.info("client is open");
                    List<AppRuleDTO> list = ruleService.getEnabledRule();
                    String msg = gson.toJson(new RouteRuleOperationDTO(OperationTypeEnum.INSERT, list));
                    send(msg);
                }
 
                @Override
                public void onMessage(String s) { }
 
                @Override
                public void onClose(int i, String s, boolean b) { }
 
                @Override
                public void onError(Exception e) {LOGGER.error("websocket client error", e);
                }
            };
 
            client.connectBlocking();
            // 应用调度线程池进行断线重连，30 秒进行一次
            executor.scheduleAtFixedRate(() -> {if (client != null && client.isClosed()) {
                    try {client.reconnectBlocking();
                    } catch (InterruptedException e) {LOGGER.error("reconnect server fail", e);
                    }
                }
            }, 10, 30, TimeUnit.SECONDS);
 
        } catch (Exception e) {LOGGER.error("websocket sync cache exception", e);
            throw new ShipException(e.getMessage());
        }
    }
 
    public <T> void send(T t) {while (!client.getReadyState().equals(ReadyState.OPEN)) {LOGGER.debug("connecting ...please wait");
        }
        client.send(gson.toJson(t));
    }
}
 

四、测试

4.1 动静路由测试

1. 本地启动 nacos ,sh startup.sh -m standalone
2. 启动 ship-admin
3. 本地启动两个 ship-example 实例。

实例 1 配置：

ship:
 http:
   app-name: order
   version: gray_1.0
   context-path: /order
   port: 8081
   admin-url: 127.0.0.1:9001

server:
 port: 8081

nacos:
 discovery:
   server-addr: 127.0.0.1:8848

实例 2 配置：

ship:
  http:
    app-name: order
    version: prod_1.0
    context-path: /order
    port: 8082
    admin-url: 127.0.0.1:9001

server:
  port: 8082

nacos:
  discovery:
    server-addr: 127.0.0.1:8848

1. 在数据库增加路由规定配置，该规定示意当 http header 中的 name=ship 时申请路由到 gray_1.0 版本的节点。

1. 启动 ship-server, 看到以下日志时则能够进行测试了。

   2021-01-02 19:57:09.159  INFO 30413 --- [SocketWorker-29] cn.sp.sync.WebsocketSyncCacheServer      : websocket server receive message:
   [{"operationType":"INSERT","ruleList":[{"id":1,"appId":5,"appName":"order","version":"gray_1.0","matchObject":"HEADER","matchKey":"name","matchMethod":1,"matchRule":"ship","priority":50}]}]

1. 用 Postman 申请 http://localhost:9000/order/u…，header 设置 name=ship，能够看到只有实例 1 有日志显示。

==========add user,version:gray_1.0

4.2 性能压测

压测环境：

MacBook Pro 13 英寸

处理器 2.3 GHz 四核 Intel Core i7

内存 16 GB 3733 MHz LPDDR4X

后端节点个数一个

压测工具：wrk

压测后果：20 个线程，500 个连接数，吞吐量大略每秒 9400 个申请。

五、总结

千里之行始于足下，开始认为写一个网关会很难，但当你理论开始口头时就会发现其实没那么难，所以迈出第一步很重要。过程中也遇到了很多问题，还在 github 上给 soul 和 nacos 这两个开源我的项目提了两个 issue，起初发现是本人的问题，难堪😅。

本文代码已全副上传到 github：https://github.com/2YSP/ship-…，最初，心愿此文对你有所帮忙。

参考资料：

https://nacos.io/zh-cn/docs/q…

https://dromara.org/website/z…

https://docs.spring.io/spring…

https://github.com/TooTallNat…

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