第300集负载均衡SLB架构实战：高可用分发、智能调度与企业级负载均衡解决方案

前言

负载均衡SLB作为企业级高可用架构的核心组件之一，直接影响着系统的可用性和性能。通过智能的流量分发策略，完善的健康检查机制，能够构建稳定可靠的负载均衡系统，保障企业级应用的高并发处理能力。本文从负载均衡架构设计到智能调度，从基础原理到企业级实践，系统梳理负载均衡SLB的完整解决方案。

一、负载均衡SLB架构设计

1.1 SLB整体架构

1.2 SLB核心组件

/**
 * SLB负载均衡核心组件
 */
@Component
public class SLBLoadBalancerManager {

    @Autowired
    private SLBConfigService slbConfigService;

    @Autowired
    private TrafficDistributionService trafficDistributionService;

    @Autowired
    private HealthCheckService healthCheckService;

    @Autowired
    private SessionPersistenceService sessionPersistenceService;

    @Autowired
    private SLBMonitorService slbMonitorService;

    @Autowired
    private SecurityProtectionService securityProtectionService;

    /**
     * 初始化SLB负载均衡器
     */
    public void initializeSLB() {
        try {
            // 1. 加载SLB配置
            loadSLBConfig();

            // 2. 初始化流量分发服务
            initializeTrafficDistribution();

            // 3. 启动健康检查服务
            startHealthCheckService();

            // 4. 配置会话保持
            configureSessionPersistence();

            // 5. 启动监控服务
            startMonitoringService();

            // 6. 配置安全防护
            configureSecurityProtection();

            log.info("SLB负载均衡器初始化完成");

        } catch (Exception e) {
            log.error("SLB负载均衡器初始化失败", e);
            throw new SLBInitializationException("SLB初始化失败", e);
        }
    }

    /**
     * 启动SLB负载均衡器
     */
    public void startSLB() {
        try {
            // 1. 检查SLB状态
            checkSLBStatus();

            // 2. 启动流量分发
            startTrafficDistribution();

            // 3. 启动健康检查
            healthCheckService.startHealthCheck();

            // 4. 启动会话保持
            sessionPersistenceService.startSessionPersistence();

            // 5. 启动监控
            slbMonitorService.startMonitoring();

            // 6. 验证SLB健康状态
            validateSLBHealth();

            log.info("SLB负载均衡器启动成功");

        } catch (Exception e) {
            log.error("SLB负载均衡器启动失败", e);
            throw new SLBStartException("SLB启动失败", e);
        }
    }

    /**
     * 停止SLB负载均衡器
     */
    public void stopSLB() {
        try {
            // 1. 停止监控
            slbMonitorService.stopMonitoring();

            // 2. 停止会话保持
            sessionPersistenceService.stopSessionPersistence();

            // 3. 停止健康检查
            healthCheckService.stopHealthCheck();

            // 4. 停止流量分发
            stopTrafficDistribution();

            log.info("SLB负载均衡器停止成功");

        } catch (Exception e) {
            log.error("SLB负载均衡器停止失败", e);
        }
    }

    /**
     * 加载SLB配置
     */
    private void loadSLBConfig() {
        // 实现SLB配置加载逻辑
        log.info("加载SLB配置");
    }

    /**
     * 初始化流量分发服务
     */
    private void initializeTrafficDistribution() {
        // 实现流量分发服务初始化逻辑
        log.info("初始化流量分发服务");
    }

    /**
     * 启动健康检查服务
     */
    private void startHealthCheckService() {
        // 实现健康检查服务启动逻辑
        log.info("启动健康检查服务");
    }

    /**
     * 配置会话保持
     */
    private void configureSessionPersistence() {
        // 实现会话保持配置逻辑
        log.info("配置会话保持");
    }

    /**
     * 启动监控服务
     */
    private void startMonitoringService() {
        // 实现监控服务启动逻辑
        log.info("启动监控服务");
    }

    /**
     * 配置安全防护
     */
    private void configureSecurityProtection() {
        // 实现安全防护配置逻辑
        log.info("配置安全防护");
    }
}

二、流量分发与调度

2.1 流量分发服务

/**
 * SLB流量分发服务
 */
@Service
public class SLBTrafficDistributionService {

    @Autowired
    private BackendServerManager backendServerManager;

    @Autowired
    private LoadBalancingAlgorithmFactory algorithmFactory;

    @Autowired
    private TrafficStatisticsService trafficStatisticsService;

    private LoadBalancingAlgorithm currentAlgorithm;

    /**
     * 分发请求
     */
    public BackendServer distributeRequest(HttpRequest request) {
        try {
            // 1. 获取后端服务器列表
            List<BackendServer> availableServers = backendServerManager.getAvailableServers();

            if (availableServers.isEmpty()) {
                throw new NoAvailableServerException("没有可用的后端服务器");
            }

            // 2. 选择负载均衡算法
            LoadBalancingAlgorithm algorithm = getLoadBalancingAlgorithm();

            // 3. 选择后端服务器
            BackendServer selectedServer = algorithm.selectServer(availableServers, request);

            // 4. 记录流量统计
            trafficStatisticsService.recordTrafficDistribution(request, selectedServer);

            // 5. 更新服务器负载
            updateServerLoad(selectedServer);

            log.debug("请求分发到服务器: {}", selectedServer.getServerId());

            return selectedServer;

        } catch (Exception e) {
            log.error("请求分发失败", e);
            throw new TrafficDistributionException("请求分发失败", e);
        }
    }

    /**
     * 分发请求（带会话保持）
     */
    public BackendServer distributeRequestWithSessionPersistence(HttpRequest request, String sessionId) {
        try {
            // 1. 检查会话保持
            BackendServer persistentServer = getPersistentServer(sessionId);
            if (persistentServer != null && persistentServer.isHealthy()) {
                trafficStatisticsService.recordTrafficDistribution(request, persistentServer);
                updateServerLoad(persistentServer);
                return persistentServer;
            }

            // 2. 正常分发请求
            BackendServer selectedServer = distributeRequest(request);

            // 3. 建立会话保持
            establishSessionPersistence(sessionId, selectedServer);

            return selectedServer;

        } catch (Exception e) {
            log.error("带会话保持的请求分发失败", e);
            throw new TrafficDistributionException("带会话保持的请求分发失败", e);
        }
    }

    /**
     * 获取负载均衡算法
     */
    private LoadBalancingAlgorithm getLoadBalancingAlgorithm() {
        if (currentAlgorithm == null) {
            // 从配置中获取算法类型
            String algorithmType = getAlgorithmTypeFromConfig();
            currentAlgorithm = algorithmFactory.createAlgorithm(algorithmType);
        }
        return currentAlgorithm;
    }

    /**
     * 更新服务器负载
     */
    private void updateServerLoad(BackendServer server) {
        try {
            server.incrementActiveConnections();
            server.updateLastRequestTime(System.currentTimeMillis());

            // 更新服务器统计信息
            backendServerManager.updateServerStatistics(server);

        } catch (Exception e) {
            log.error("更新服务器负载失败: {}", server.getServerId(), e);
        }
    }

    /**
     * 获取持久化服务器
     */
    private BackendServer getPersistentServer(String sessionId) {
        try {
            return backendServerManager.getPersistentServer(sessionId);
        } catch (Exception e) {
            log.error("获取持久化服务器失败: {}", sessionId, e);
            return null;
        }
    }

    /**
     * 建立会话保持
     */
    private void establishSessionPersistence(String sessionId, BackendServer server) {
        try {
            backendServerManager.establishSessionPersistence(sessionId, server);
        } catch (Exception e) {
            log.error("建立会话保持失败: {} -> {}", sessionId, server.getServerId(), e);
        }
    }

    /**
     * 从配置中获取算法类型
     */
    private String getAlgorithmTypeFromConfig() {
        // 实现从配置中获取算法类型的逻辑
        return "ROUND_ROBIN"; // 默认轮询算法
    }
}

2.2 负载均衡算法

/**
 * 负载均衡算法接口
 */
public interface LoadBalancingAlgorithm {

    /**
     * 选择服务器
     */
    BackendServer selectServer(List<BackendServer> servers, HttpRequest request);

    /**
     * 获取算法名称
     */
    String getAlgorithmName();
}

/**
 * 轮询算法
 */
@Component
public class RoundRobinAlgorithm implements LoadBalancingAlgorithm {

    private final AtomicInteger currentIndex = new AtomicInteger(0);

    @Override
    public BackendServer selectServer(List<BackendServer> servers, HttpRequest request) {
        if (servers.isEmpty()) {
            throw new NoAvailableServerException("没有可用的服务器");
        }

        int index = currentIndex.getAndIncrement() % servers.size();
        return servers.get(index);
    }

    @Override
    public String getAlgorithmName() {
        return "ROUND_ROBIN";
    }
}

/**
 * 加权轮询算法
 */
@Component
public class WeightedRoundRobinAlgorithm implements LoadBalancingAlgorithm {

    private final AtomicInteger currentIndex = new AtomicInteger(0);
    private final AtomicInteger currentWeight = new AtomicInteger(0);

    @Override
    public BackendServer selectServer(List<BackendServer> servers, HttpRequest request) {
        if (servers.isEmpty()) {
            throw new NoAvailableServerException("没有可用的服务器");
        }

        int maxWeight = servers.stream().mapToInt(BackendServer::getWeight).max().orElse(1);
        int gcd = calculateGCD(servers);

        while (true) {
            int index = currentIndex.getAndIncrement() % servers.size();
            BackendServer server = servers.get(index);

            if (index == 0) {
                currentWeight.addAndGet(-gcd);
                if (currentWeight.get() <= 0) {
                    currentWeight.set(maxWeight);
                }
            }

            if (server.getWeight() >= currentWeight.get()) {
                return server;
            }
        }
    }

    @Override
    public String getAlgorithmName() {
        return "WEIGHTED_ROUND_ROBIN";
    }

    /**
     * 计算最大公约数
     */
    private int calculateGCD(List<BackendServer> servers) {
        int gcd = servers.get(0).getWeight();
        for (int i = 1; i < servers.size(); i++) {
            gcd = calculateGCD(gcd, servers.get(i).getWeight());
        }
        return gcd;
    }

    /**
     * 计算两个数的最大公约数
     */
    private int calculateGCD(int a, int b) {
        while (b != 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }
}

/**
 * 最少连接算法
 */
@Component
public class LeastConnectionsAlgorithm implements LoadBalancingAlgorithm {

    @Override
    public BackendServer selectServer(List<BackendServer> servers, HttpRequest request) {
        if (servers.isEmpty()) {
            throw new NoAvailableServerException("没有可用的服务器");
        }

        return servers.stream()
            .min(Comparator.comparingInt(BackendServer::getActiveConnections))
            .orElse(servers.get(0));
    }

    @Override
    public String getAlgorithmName() {
        return "LEAST_CONNECTIONS";
    }
}

/**
 * 源IP哈希算法
 */
@Component
public class SourceIPHashAlgorithm implements LoadBalancingAlgorithm {

    @Override
    public BackendServer selectServer(List<BackendServer> servers, HttpRequest request) {
        if (servers.isEmpty()) {
            throw new NoAvailableServerException("没有可用的服务器");
        }

        String clientIP = getClientIP(request);
        int hash = clientIP.hashCode();
        int index = Math.abs(hash) % servers.size();

        return servers.get(index);
    }

    @Override
    public String getAlgorithmName() {
        return "SOURCE_IP_HASH";
    }

    /**
     * 获取客户端IP
     */
    private String getClientIP(HttpRequest request) {
        String xForwardedFor = request.getHeader("X-Forwarded-For");
        if (xForwardedFor != null && !xForwardedFor.isEmpty()) {
            return xForwardedFor.split(",")[0].trim();
        }

        String xRealIP = request.getHeader("X-Real-IP");
        if (xRealIP != null && !xRealIP.isEmpty()) {
            return xRealIP;
        }

        return request.getRemoteAddr();
    }
}

/**
 * 一致性哈希算法
 */
@Component
public class ConsistentHashAlgorithm implements LoadBalancingAlgorithm {

    private final TreeMap<Long, BackendServer> hashRing = new TreeMap<>();
    private final int virtualNodes = 150; // 虚拟节点数

    @Override
    public BackendServer selectServer(List<BackendServer> servers, HttpRequest request) {
        if (servers.isEmpty()) {
            throw new NoAvailableServerException("没有可用的服务器");
        }

        // 构建哈希环
        buildHashRing(servers);

        // 计算请求的哈希值
        String key = getRequestKey(request);
        long hash = hash(key);

        // 查找最近的服务器
        Map.Entry<Long, BackendServer> entry = hashRing.ceilingEntry(hash);
        if (entry == null) {
            entry = hashRing.firstEntry();
        }

        return entry.getValue();
    }

    @Override
    public String getAlgorithmName() {
        return "CONSISTENT_HASH";
    }

    /**
     * 构建哈希环
     */
    private void buildHashRing(List<BackendServer> servers) {
        hashRing.clear();

        for (BackendServer server : servers) {
            for (int i = 0; i < virtualNodes; i++) {
                String virtualNodeKey = server.getServerId() + "#" + i;
                long hash = hash(virtualNodeKey);
                hashRing.put(hash, server);
            }
        }
    }

    /**
     * 计算哈希值
     */
    private long hash(String key) {
        return key.hashCode() & 0x7FFFFFFF;
    }

    /**
     * 获取请求键
     */
    private String getRequestKey(HttpRequest request) {
        String clientIP = getClientIP(request);
        String uri = request.getRequestURI();
        return clientIP + ":" + uri;
    }

    /**
     * 获取客户端IP
     */
    private String getClientIP(HttpRequest request) {
        String xForwardedFor = request.getHeader("X-Forwarded-For");
        if (xForwardedFor != null && !xForwardedFor.isEmpty()) {
            return xForwardedFor.split(",")[0].trim();
        }

        String xRealIP = request.getHeader("X-Real-IP");
        if (xRealIP != null && !xRealIP.isEmpty()) {
            return xRealIP;
        }

        return request.getRemoteAddr();
    }
}

2.3 负载均衡算法工厂

/**
 * 负载均衡算法工厂
 */
@Component
public class LoadBalancingAlgorithmFactory {

    @Autowired
    private ApplicationContext applicationContext;

    private final Map<String, Class<? extends LoadBalancingAlgorithm>> algorithmMap;

    public LoadBalancingAlgorithmFactory() {
        this.algorithmMap = new HashMap<>();
        initializeAlgorithmMap();
    }

    /**
     * 创建负载均衡算法
     */
    public LoadBalancingAlgorithm createAlgorithm(String algorithmType) {
        Class<? extends LoadBalancingAlgorithm> algorithmClass = algorithmMap.get(algorithmType);
        if (algorithmClass == null) {
            throw new UnsupportedAlgorithmException("不支持的负载均衡算法: " + algorithmType);
        }

        try {
            return applicationContext.getBean(algorithmClass);
        } catch (Exception e) {
            log.error("创建负载均衡算法失败: {}", algorithmType, e);
            throw new AlgorithmCreationException("创建负载均衡算法失败", e);
        }
    }

    /**
     * 获取支持的算法类型
     */
    public Set<String> getSupportedAlgorithmTypes() {
        return algorithmMap.keySet();
    }

    /**
     * 初始化算法映射
     */
    private void initializeAlgorithmMap() {
        algorithmMap.put("ROUND_ROBIN", RoundRobinAlgorithm.class);
        algorithmMap.put("WEIGHTED_ROUND_ROBIN", WeightedRoundRobinAlgorithm.class);
        algorithmMap.put("LEAST_CONNECTIONS", LeastConnectionsAlgorithm.class);
        algorithmMap.put("SOURCE_IP_HASH", SourceIPHashAlgorithm.class);
        algorithmMap.put("CONSISTENT_HASH", ConsistentHashAlgorithm.class);
    }
}

三、健康检查与监控

3.1 健康检查服务

/**
 * SLB健康检查服务
 */
@Service
public class SLBHealthCheckService {

    @Autowired
    private BackendServerManager backendServerManager;

    @Autowired
    private HealthCheckConfigService healthCheckConfigService;

    @Autowired
    private HealthCheckExecutor healthCheckExecutor;

    private final ScheduledExecutorService healthCheckScheduler;

    public SLBHealthCheckService() {
        this.healthCheckScheduler = Executors.newScheduledThreadPool(10);
    }

    /**
     * 启动健康检查
     */
    public void startHealthCheck() {
        try {
            // 获取健康检查配置
            List<HealthCheckConfig> configs = healthCheckConfigService.getAllHealthCheckConfigs();

            // 为每个配置启动健康检查任务
            for (HealthCheckConfig config : configs) {
                startHealthCheckTask(config);
            }

            log.info("SLB健康检查启动成功");

        } catch (Exception e) {
            log.error("SLB健康检查启动失败", e);
            throw new HealthCheckStartException("健康检查启动失败", e);
        }
    }

    /**
     * 停止健康检查
     */
    public void stopHealthCheck() {
        try {
            healthCheckScheduler.shutdown();
            if (!healthCheckScheduler.awaitTermination(30, TimeUnit.SECONDS)) {
                healthCheckScheduler.shutdownNow();
            }

            log.info("SLB健康检查停止成功");

        } catch (Exception e) {
            log.error("SLB健康检查停止失败", e);
        }
    }

    /**
     * 启动健康检查任务
     */
    private void startHealthCheckTask(HealthCheckConfig config) {
        try {
            // 创建健康检查任务
            HealthCheckTask task = new HealthCheckTask(config);

            // 调度健康检查任务
            healthCheckScheduler.scheduleAtFixedRate(
                task,
                config.getInitialDelay(),
                config.getCheckInterval(),
                TimeUnit.MILLISECONDS
            );

            log.info("健康检查任务启动成功: {}", config.getConfigId());

        } catch (Exception e) {
            log.error("健康检查任务启动失败: {}", config.getConfigId(), e);
        }
    }

    /**
     * 健康检查任务
     */
    private class HealthCheckTask implements Runnable {

        private final HealthCheckConfig config;

        public HealthCheckTask(HealthCheckConfig config) {
            this.config = config;
        }

        @Override
        public void run() {
            try {
                // 获取需要检查的服务器
                List<BackendServer> servers = backendServerManager.getServersByConfig(config.getConfigId());

                // 执行健康检查
                for (BackendServer server : servers) {
                    performHealthCheck(server, config);
                }

            } catch (Exception e) {
                log.error("健康检查任务执行失败: {}", config.getConfigId(), e);
            }
        }

        /**
         * 执行健康检查
         */
        private void performHealthCheck(BackendServer server, HealthCheckConfig config) {
            try {
                // 创建健康检查请求
                HealthCheckRequest request = createHealthCheckRequest(server, config);

                // 执行健康检查
                HealthCheckResult result = healthCheckExecutor.executeHealthCheck(request);

                // 更新服务器健康状态
                updateServerHealthStatus(server, result);

                // 记录健康检查结果
                recordHealthCheckResult(server, result);

            } catch (Exception e) {
                log.error("服务器健康检查失败: {}", server.getServerId(), e);

                // 标记服务器为不健康
                markServerUnhealthy(server);
            }
        }

        /**
         * 创建健康检查请求
         */
        private HealthCheckRequest createHealthCheckRequest(BackendServer server, HealthCheckConfig config) {
            HealthCheckRequest request = new HealthCheckRequest();
            request.setServer(server);
            request.setCheckType(config.getCheckType());
            request.setCheckUrl(config.getCheckUrl());
            request.setCheckPort(config.getCheckPort());
            request.setTimeout(config.getTimeout());
            request.setRetryCount(config.getRetryCount());
            request.setSuccessThreshold(config.getSuccessThreshold());
            request.setFailureThreshold(config.getFailureThreshold());

            return request;
        }

        /**
         * 更新服务器健康状态
         */
        private void updateServerHealthStatus(BackendServer server, HealthCheckResult result) {
            try {
                if (result.isHealthy()) {
                    server.markHealthy();
                } else {
                    server.markUnhealthy();
                }

                // 更新服务器统计信息
                backendServerManager.updateServerStatistics(server);

            } catch (Exception e) {
                log.error("更新服务器健康状态失败: {}", server.getServerId(), e);
            }
        }

        /**
         * 记录健康检查结果
         */
        private void recordHealthCheckResult(BackendServer server, HealthCheckResult result) {
            try {
                // 实现健康检查结果记录逻辑
                log.debug("健康检查结果: {} -> {}", server.getServerId(), result.isHealthy());

            } catch (Exception e) {
                log.error("记录健康检查结果失败: {}", server.getServerId(), e);
            }
        }

        /**
         * 标记服务器为不健康
         */
        private void markServerUnhealthy(BackendServer server) {
            try {
                server.markUnhealthy();
                backendServerManager.updateServerStatistics(server);

            } catch (Exception e) {
                log.error("标记服务器为不健康失败: {}", server.getServerId(), e);
            }
        }
    }
}

3.2 健康检查执行器

/**
 * SLB健康检查执行器
 */
@Component
public class SLBHealthCheckExecutor {

    @Autowired
    private HttpClient httpClient;

    @Autowired
    private TcpClient tcpClient;

    @Autowired
    private UdpClient udpClient;

    /**
     * 执行健康检查
     */
    public HealthCheckResult executeHealthCheck(HealthCheckRequest request) {
        try {
            switch (request.getCheckType()) {
                case HTTP:
                    return executeHttpHealthCheck(request);
                case TCP:
                    return executeTcpHealthCheck(request);
                case UDP:
                    return executeUdpHealthCheck(request);
                case CUSTOM:
                    return executeCustomHealthCheck(request);
                default:
                    throw new UnsupportedCheckTypeException("不支持的健康检查类型: " + request.getCheckType());
            }

        } catch (Exception e) {
            log.error("健康检查执行失败: {}", request.getServer().getServerId(), e);
            return createFailureResult(request, e.getMessage());
        }
    }

    /**
     * 执行HTTP健康检查
     */
    private HealthCheckResult executeHttpHealthCheck(HealthCheckRequest request) {
        try {
            BackendServer server = request.getServer();
            String checkUrl = request.getCheckUrl();
            int timeout = request.getTimeout();

            // 构建完整的检查URL
            String fullUrl = buildFullUrl(server, checkUrl);

            // 执行HTTP请求
            HttpResponse response = httpClient.get(fullUrl, timeout);

            // 检查响应状态
            boolean isHealthy = isHttpResponseHealthy(response);

            // 创建健康检查结果
            HealthCheckResult result = new HealthCheckResult();
            result.setHealthy(isHealthy);
            result.setResponseTime(response.getResponseTime());
            result.setStatusCode(response.getStatusCode());
            result.setResponseBody(response.getBody());
            result.setErrorMessage(isHealthy ? null : "HTTP响应不健康");

            return result;

        } catch (Exception e) {
            log.error("HTTP健康检查失败: {}", request.getServer().getServerId(), e);
            return createFailureResult(request, "HTTP健康检查失败: " + e.getMessage());
        }
    }

    /**
     * 执行TCP健康检查
     */
    private HealthCheckResult executeTcpHealthCheck(HealthCheckRequest request) {
        try {
            BackendServer server = request.getServer();
            int checkPort = request.getCheckPort();
            int timeout = request.getTimeout();

            // 执行TCP连接测试
            long startTime = System.currentTimeMillis();
            boolean isConnected = tcpClient.testConnection(server.getHost(), checkPort, timeout);
            long responseTime = System.currentTimeMillis() - startTime;

            // 创建健康检查结果
            HealthCheckResult result = new HealthCheckResult();
            result.setHealthy(isConnected);
            result.setResponseTime(responseTime);
            result.setErrorMessage(isConnected ? null : "TCP连接失败");

            return result;

        } catch (Exception e) {
            log.error("TCP健康检查失败: {}", request.getServer().getServerId(), e);
            return createFailureResult(request, "TCP健康检查失败: " + e.getMessage());
        }
    }

    /**
     * 执行UDP健康检查
     */
    private HealthCheckResult executeUdpHealthCheck(HealthCheckRequest request) {
        try {
            BackendServer server = request.getServer();
            int checkPort = request.getCheckPort();
            int timeout = request.getTimeout();

            // 执行UDP连接测试
            long startTime = System.currentTimeMillis();
            boolean isConnected = udpClient.testConnection(server.getHost(), checkPort, timeout);
            long responseTime = System.currentTimeMillis() - startTime;

            // 创建健康检查结果
            HealthCheckResult result = new HealthCheckResult();
            result.setHealthy(isConnected);
            result.setResponseTime(responseTime);
            result.setErrorMessage(isConnected ? null : "UDP连接失败");

            return result;

        } catch (Exception e) {
            log.error("UDP健康检查失败: {}", request.getServer().getServerId(), e);
            return createFailureResult(request, "UDP健康检查失败: " + e.getMessage());
        }
    }

    /**
     * 执行自定义健康检查
     */
    private HealthCheckResult executeCustomHealthCheck(HealthCheckRequest request) {
        try {
            BackendServer server = request.getServer();
            String checkUrl = request.getCheckUrl();
            int timeout = request.getTimeout();

            // 执行自定义健康检查
            long startTime = System.currentTimeMillis();
            CustomHealthCheckResult customResult = executeCustomCheck(server, checkUrl, timeout);
            long responseTime = System.currentTimeMillis() - startTime;

            // 创建健康检查结果
            HealthCheckResult result = new HealthCheckResult();
            result.setHealthy(customResult.isHealthy());
            result.setResponseTime(responseTime);
            result.setResponseBody(customResult.getResponseBody());
            result.setErrorMessage(customResult.isHealthy() ? null : customResult.getErrorMessage());

            return result;

        } catch (Exception e) {
            log.error("自定义健康检查失败: {}", request.getServer().getServerId(), e);
            return createFailureResult(request, "自定义健康检查失败: " + e.getMessage());
        }
    }

    /**
     * 检查HTTP响应是否健康
     */
    private boolean isHttpResponseHealthy(HttpResponse response) {
        // 检查状态码
        int statusCode = response.getStatusCode();
        if (statusCode < 200 || statusCode >= 300) {
            return false;
        }

        // 检查响应体
        String responseBody = response.getBody();
        if (responseBody != null && responseBody.contains("error")) {
            return false;
        }

        return true;
    }

    /**
     * 构建完整的检查URL
     */
    private String buildFullUrl(BackendServer server, String checkUrl) {
        if (checkUrl.startsWith("http://") || checkUrl.startsWith("https://")) {
            return checkUrl;
        }

        return "http://" + server.getHost() + ":" + server.getPort() + checkUrl;
    }

    /**
     * 执行自定义检查
     */
    private CustomHealthCheckResult executeCustomCheck(BackendServer server, String checkUrl, int timeout) {
        // 实现自定义健康检查逻辑
        CustomHealthCheckResult result = new CustomHealthCheckResult();
        result.setHealthy(true);
        result.setResponseBody("OK");
        result.setErrorMessage(null);

        return result;
    }

    /**
     * 创建失败结果
     */
    private HealthCheckResult createFailureResult(HealthCheckRequest request, String errorMessage) {
        HealthCheckResult result = new HealthCheckResult();
        result.setHealthy(false);
        result.setResponseTime(0);
        result.setErrorMessage(errorMessage);

        return result;
    }
}

3.3 SLB监控服务

/**
 * SLB监控服务
 */
@Service
public class SLBMonitorService {

    @Autowired
    private SLBMetricsCollector metricsCollector;

    @Autowired
    private SLBHealthAnalyzer healthAnalyzer;

    @Autowired
    private AlertService alertService;

    private final ScheduledExecutorService monitorScheduler;

    public SLBMonitorService() {
        this.monitorScheduler = Executors.newScheduledThreadPool(5);
    }

    /**
     * 启动SLB监控
     */
    public void startMonitoring() {
        // 启动定期监控任务
        monitorScheduler.scheduleAtFixedRate(
            this::monitorSLB,
            0,
            60, // 1分钟
            TimeUnit.SECONDS
        );

        log.info("SLB监控启动成功");
    }

    /**
     * 停止SLB监控
     */
    public void stopMonitoring() {
        try {
            monitorScheduler.shutdown();
            if (!monitorScheduler.awaitTermination(30, TimeUnit.SECONDS)) {
                monitorScheduler.shutdownNow();
            }

            log.info("SLB监控停止成功");

        } catch (Exception e) {
            log.error("SLB监控停止失败", e);
        }
    }

    /**
     * 监控SLB
     */
    private void monitorSLB() {
        try {
            // 1. 收集SLB指标
            SLBMetrics metrics = metricsCollector.collectMetrics();

            // 2. 分析SLB健康状态
            SLBHealthStatus healthStatus = healthAnalyzer.analyzeHealth(metrics);

            // 3. 检查SLB状态
            if (!healthStatus.isHealthy()) {
                handleUnhealthySLB(healthStatus);
            }

            // 4. 记录监控结果
            recordMonitoringResult(metrics, healthStatus);

        } catch (Exception e) {
            log.error("SLB监控失败", e);
        }
    }

    /**
     * 处理不健康SLB
     */
    private void handleUnhealthySLB(SLBHealthStatus healthStatus) {
        try {
            // 1. 发送SLB告警
            sendSLBAlert(healthStatus);

            // 2. 记录SLB问题
            recordSLBIssue(healthStatus);

        } catch (Exception e) {
            log.error("不健康SLB处理失败", e);
        }
    }

    /**
     * 发送SLB告警
     */
    private void sendSLBAlert(SLBHealthStatus healthStatus) {
        SLBAlert alert = new SLBAlert();
        alert.setAlertType(AlertType.SLB_UNHEALTHY);
        alert.setSeverity(healthStatus.getSeverity());
        alert.setMessage("SLB负载均衡器状态异常");
        alert.setHealthStatus(healthStatus);
        alert.setTimestamp(System.currentTimeMillis());

        // 发送告警
        alertService.sendAlert(alert);
    }

    /**
     * 记录监控结果
     */
    private void recordMonitoringResult(SLBMetrics metrics, SLBHealthStatus healthStatus) {
        SLBMonitoringResult result = new SLBMonitoringResult();
        result.setTimestamp(System.currentTimeMillis());
        result.setMetrics(metrics);
        result.setHealthStatus(healthStatus);

        // 存储监控结果
        // monitoringResultStorage.store(result);
    }
}

四、会话保持与安全防护

4.1 会话保持服务

/**
 * SLB会话保持服务
 */
@Service
public class SLBSessionPersistenceService {

    @Autowired
    private SessionPersistenceConfigService configService;

    @Autowired
    private SessionStorageService sessionStorageService;

    @Autowired
    private BackendServerManager backendServerManager;

    private final ScheduledExecutorService sessionCleanupScheduler;

    public SLBSessionPersistenceService() {
        this.sessionCleanupScheduler = Executors.newScheduledThreadPool(2);
    }

    /**
     * 启动会话保持
     */
    public void startSessionPersistence() {
        try {
            // 启动会话清理任务
            sessionCleanupScheduler.scheduleAtFixedRate(
                this::cleanupExpiredSessions,
                0,
                300, // 5分钟
                TimeUnit.SECONDS
            );

            log.info("SLB会话保持启动成功");

        } catch (Exception e) {
            log.error("SLB会话保持启动失败", e);
            throw new SessionPersistenceStartException("会话保持启动失败", e);
        }
    }

    /**
     * 停止会话保持
     */
    public void stopSessionPersistence() {
        try {
            sessionCleanupScheduler.shutdown();
            if (!sessionCleanupScheduler.awaitTermination(30, TimeUnit.SECONDS)) {
                sessionCleanupScheduler.shutdownNow();
            }

            log.info("SLB会话保持停止成功");

        } catch (Exception e) {
            log.error("SLB会话保持停止失败", e);
        }
    }

    /**
     * 建立会话保持
     */
    public void establishSessionPersistence(String sessionId, BackendServer server) {
        try {
            // 获取会话保持配置
            SessionPersistenceConfig config = configService.getSessionPersistenceConfig();

            // 创建会话保持记录
            SessionPersistenceRecord record = new SessionPersistenceRecord();
            record.setSessionId(sessionId);
            record.setServerId(server.getServerId());
            record.setServer(server);
            record.setCreateTime(System.currentTimeMillis());
            record.setExpireTime(System.currentTimeMillis() + config.getSessionTimeout());
            record.setPersistenceType(config.getPersistenceType());

            // 存储会话保持记录
            sessionStorageService.storeSession(record);

            log.debug("会话保持建立成功: {} -> {}", sessionId, server.getServerId());

        } catch (Exception e) {
            log.error("建立会话保持失败: {} -> {}", sessionId, server.getServerId(), e);
        }
    }

    /**
     * 获取会话保持的服务器
     */
    public BackendServer getPersistentServer(String sessionId) {
        try {
            // 从存储中获取会话保持记录
            SessionPersistenceRecord record = sessionStorageService.getSession(sessionId);

            if (record == null) {
                return null;
            }

            // 检查会话是否过期
            if (System.currentTimeMillis() > record.getExpireTime()) {
                sessionStorageService.removeSession(sessionId);
                return null;
            }

            // 检查服务器是否健康
            BackendServer server = record.getServer();
            if (!server.isHealthy()) {
                sessionStorageService.removeSession(sessionId);
                return null;
            }

            // 更新会话访问时间
            record.setLastAccessTime(System.currentTimeMillis());
            sessionStorageService.updateSession(record);

            return server;

        } catch (Exception e) {
            log.error("获取会话保持服务器失败: {}", sessionId, e);
            return null;
        }
    }

    /**
     * 清理过期会话
     */
    private void cleanupExpiredSessions() {
        try {
            // 获取所有会话
            List<SessionPersistenceRecord> allSessions = sessionStorageService.getAllSessions();

            long currentTime = System.currentTimeMillis();
            int expiredCount = 0;

            // 清理过期会话
            for (SessionPersistenceRecord record : allSessions) {
                if (currentTime > record.getExpireTime()) {
                    sessionStorageService.removeSession(record.getSessionId());
                    expiredCount++;
                }
            }

            if (expiredCount > 0) {
                log.info("清理过期会话完成，清理数量: {}", expiredCount);
            }

        } catch (Exception e) {
            log.error("清理过期会话失败", e);
        }
    }
}

4.2 安全防护服务

/**
 * SLB安全防护服务
 */
@Service
public class SLBSecurityProtectionService {

    @Autowired
    private DDoSProtectionService ddosProtectionService;

    @Autowired
    private WAFProtectionService wafProtectionService;

    @Autowired
    private SSLTerminationService sslTerminationService;

    @Autowired
    private AccessControlService accessControlService;

    /**
     * 配置安全防护
     */
    public void configureSecurityProtection() {
        try {
            // 1. 配置DDoS防护
            configureDDoSProtection();

            // 2. 配置WAF防护
            configureWAFProtection();

            // 3. 配置SSL卸载
            configureSSLTermination();

            // 4. 配置访问控制
            configureAccessControl();

            log.info("SLB安全防护配置完成");

        } catch (Exception e) {
            log.error("SLB安全防护配置失败", e);
            throw new SecurityProtectionConfigurationException("安全防护配置失败", e);
        }
    }

    /**
     * 处理请求安全检查
     */
    public SecurityCheckResult checkRequestSecurity(HttpRequest request) {
        SecurityCheckResult result = new SecurityCheckResult();

        try {
            // 1. DDoS检查
            DDoSCheckResult ddosResult = ddosProtectionService.checkDDoS(request);
            if (!ddosResult.isAllowed()) {
                result.setAllowed(false);
                result.setReason("DDoS攻击检测");
                result.setAction(SecurityAction.BLOCK);
                return result;
            }

            // 2. WAF检查
            WAFCheckResult wafResult = wafProtectionService.checkWAF(request);
            if (!wafResult.isAllowed()) {
                result.setAllowed(false);
                result.setReason("WAF规则匹配");
                result.setAction(SecurityAction.BLOCK);
                return result;
            }

            // 3. 访问控制检查
            AccessControlResult accessResult = accessControlService.checkAccess(request);
            if (!accessResult.isAllowed()) {
                result.setAllowed(false);
                result.setReason("访问控制拒绝");
                result.setAction(SecurityAction.BLOCK);
                return result;
            }

            // 4. SSL检查
            SSLCheckResult sslResult = sslTerminationService.checkSSL(request);
            if (!sslResult.isValid()) {
                result.setAllowed(false);
                result.setReason("SSL证书无效");
                result.setAction(SecurityAction.REDIRECT);
                return result;
            }

            result.setAllowed(true);
            result.setAction(SecurityAction.ALLOW);

        } catch (Exception e) {
            log.error("请求安全检查失败", e);
            result.setAllowed(false);
            result.setReason("安全检查异常");
            result.setAction(SecurityAction.BLOCK);
        }

        return result;
    }

    /**
     * 配置DDoS防护
     */
    private void configureDDoSProtection() {
        try {
            DDoSProtectionConfig config = new DDoSProtectionConfig();
            config.setEnabled(true);
            config.setRateLimit(1000); // 每秒1000个请求
            config.setBurstLimit(2000); // 突发限制2000个请求
            config.setBlockDuration(300); // 封禁5分钟

            ddosProtectionService.configure(config);

            log.info("DDoS防护配置完成");

        } catch (Exception e) {
            log.error("DDoS防护配置失败", e);
            throw new DDoSProtectionConfigurationException("DDoS防护配置失败", e);
        }
    }

    /**
     * 配置WAF防护
     */
    private void configureWAFProtection() {
        try {
            WAFProtectionConfig config = new WAFProtectionConfig();
            config.setEnabled(true);
            config.setRuleSet("OWASP_CRS"); // OWASP核心规则集
            config.setMode(WAFMode.PROTECT); // 保护模式
            config.setLogLevel(WAFLogLevel.INFO);

            wafProtectionService.configure(config);

            log.info("WAF防护配置完成");

        } catch (Exception e) {
            log.error("WAF防护配置失败", e);
            throw new WAFProtectionConfigurationException("WAF防护配置失败", e);
        }
    }

    /**
     * 配置SSL卸载
     */
    private void configureSSLTermination() {
        try {
            SSLTerminationConfig config = new SSLTerminationConfig();
            config.setEnabled(true);
            config.setCertificatePath("/etc/ssl/certs/server.crt");
            config.setPrivateKeyPath("/etc/ssl/private/server.key");
            config.setProtocols("TLSv1.2,TLSv1.3");
            config.setCiphers("ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256");

            sslTerminationService.configure(config);

            log.info("SSL卸载配置完成");

        } catch (Exception e) {
            log.error("SSL卸载配置失败", e);
            throw new SSLTerminationConfigurationException("SSL卸载配置失败", e);
        }
    }

    /**
     * 配置访问控制
     */
    private void configureAccessControl() {
        try {
            AccessControlConfig config = new AccessControlConfig();
            config.setEnabled(true);
            config.setDefaultAction(AccessAction.ALLOW);
            config.setBlacklistEnabled(true);
            config.setWhitelistEnabled(true);

            accessControlService.configure(config);

            log.info("访问控制配置完成");

        } catch (Exception e) {
            log.error("访问控制配置失败", e);
            throw new AccessControlConfigurationException("访问控制配置失败", e);
        }
    }
}

五、企业级SLB方案

5.1 SLB配置管理

/**
 * SLB配置管理服务
 */
@Service
public class SLBConfigManagementService {

    @Autowired
    private ConfigurationRepository configRepository;

    @Autowired
    private SLBConfigValidator configValidator;

    @Autowired
    private SLBConfigApplier configApplier;

    /**
     * 获取SLB配置
     */
    public SLBConfig getSLBConfig(String configId) {
        return configRepository.findSLBConfigById(configId)
            .orElseThrow(() -> new ConfigNotFoundException("SLB配置不存在: " + configId));
    }

    /**
     * 保存SLB配置
     */
    public void saveSLBConfig(SLBConfig config) {
        try {
            // 验证配置
            configValidator.validateSLBConfig(config);

            // 保存配置
            configRepository.saveSLBConfig(config);

            // 应用配置
            configApplier.applySLBConfig(config);

            log.info("SLB配置保存成功: {}", config.getConfigId());

        } catch (Exception e) {
            log.error("SLB配置保存失败", e);
            throw new ConfigSaveException("SLB配置保存失败", e);
        }
    }

    /**
     * 更新SLB配置
     */
    public void updateSLBConfig(String configId, SLBConfig config) {
        try {
            // 检查配置是否存在
            if (!configRepository.existsSLBConfig(configId)) {
                throw new ConfigNotFoundException("SLB配置不存在: " + configId);
            }

            // 验证配置
            configValidator.validateSLBConfig(config);

            // 更新配置
            config.setConfigId(configId);
            configRepository.saveSLBConfig(config);

            // 应用配置
            configApplier.applySLBConfig(config);

            log.info("SLB配置更新成功: {}", configId);

        } catch (Exception e) {
            log.error("SLB配置更新失败", e);
            throw new ConfigUpdateException("SLB配置更新失败", e);
        }
    }

    /**
     * 删除SLB配置
     */
    public void deleteSLBConfig(String configId) {
        try {
            if (!configRepository.existsSLBConfig(configId)) {
                throw new ConfigNotFoundException("SLB配置不存在: " + configId);
            }

            configRepository.deleteSLBConfig(configId);

            log.info("SLB配置删除成功: {}", configId);

        } catch (Exception e) {
            log.error("SLB配置删除失败", e);
            throw new ConfigDeleteException("SLB配置删除失败", e);
        }
    }

    /**
     * 获取所有SLB配置
     */
    public List<SLBConfig> getAllSLBConfigs() {
        return configRepository.findAllSLBConfigs();
    }

    /**
     * 克隆SLB配置
     */
    public SLBConfig cloneSLBConfig(String sourceConfigId, String targetConfigId) {
        try {
            // 获取源配置
            SLBConfig sourceConfig = getSLBConfig(sourceConfigId);

            // 创建目标配置
            SLBConfig targetConfig = new SLBConfig();
            targetConfig.setConfigId(targetConfigId);
            targetConfig.setConfigName(sourceConfig.getConfigName() + "_clone");
            targetConfig.setLoadBalancingAlgorithm(sourceConfig.getLoadBalancingAlgorithm());
            targetConfig.setHealthCheckConfig(sourceConfig.getHealthCheckConfig());
            targetConfig.setSessionPersistenceConfig(sourceConfig.getSessionPersistenceConfig());
            targetConfig.setSecurityConfig(sourceConfig.getSecurityConfig());
            targetConfig.setBackendServers(sourceConfig.getBackendServers());

            // 保存目标配置
            saveSLBConfig(targetConfig);

            return targetConfig;

        } catch (Exception e) {
            log.error("SLB配置克隆失败", e);
            throw new ConfigCloneException("SLB配置克隆失败", e);
        }
    }

    /**
     * 导出SLB配置
     */
    public String exportSLBConfig(String configId) {
        try {
            SLBConfig config = getSLBConfig(configId);

            // 转换为JSON格式
            ObjectMapper mapper = new ObjectMapper();
            mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
            mapper.enable(SerializationFeature.INDENT_OUTPUT);

            return mapper.writeValueAsString(config);

        } catch (Exception e) {
            log.error("SLB配置导出失败", e);
            throw new ConfigExportException("SLB配置导出失败", e);
        }
    }

    /**
     * 导入SLB配置
     */
    public SLBConfig importSLBConfig(String configJson) {
        try {
            // 解析JSON配置
            ObjectMapper mapper = new ObjectMapper();
            SLBConfig config = mapper.readValue(configJson, SLBConfig.class);

            // 生成新的配置ID
            config.setConfigId(UUID.randomUUID().toString());

            // 保存配置
            saveSLBConfig(config);

            return config;

        } catch (Exception e) {
            log.error("SLB配置导入失败", e);
            throw new ConfigImportException("SLB配置导入失败", e);
        }
    }
}

5.2 SLB性能优化器

/**
 * SLB性能优化器
 */
@Service
public class SLBPerformanceOptimizer {

    @Autowired
    private SLBMetricsCollector metricsCollector;

    @Autowired
    private SLBPerformanceAnalyzer performanceAnalyzer;

    @Autowired
    private SLBConfigManagementService configManagementService;

    /**
     * 优化SLB性能
     */
    public void optimizeSLBPerformance() {
        try {
            // 1. 收集当前性能指标
            SLBMetrics currentMetrics = metricsCollector.collectMetrics();

            // 2. 分析当前性能
            SLBPerformanceAnalysis analysis = performanceAnalyzer.analyzePerformance(currentMetrics);

            // 3. 生成优化建议
            List<OptimizationSuggestion> suggestions = generateOptimizationSuggestions(analysis);

            // 4. 应用优化建议
            applyOptimizationSuggestions(suggestions);

            log.info("SLB性能优化完成");

        } catch (Exception e) {
            log.error("SLB性能优化失败", e);
            throw new SLBPerformanceOptimizationException("SLB性能优化失败", e);
        }
    }

    /**
     * 自动优化SLB性能
     */
    public void autoOptimizeSLBPerformance() {
        try {
            // 1. 收集历史性能数据
            List<SLBMetrics> historicalMetrics = metricsCollector.collectHistoricalMetrics();

            // 2. 分析性能趋势
            PerformanceTrendAnalysis trendAnalysis = performanceAnalyzer.analyzePerformanceTrend(historicalMetrics);

            // 3. 预测未来性能需求
            PerformancePrediction prediction = performanceAnalyzer.predictPerformanceNeeds(trendAnalysis);

            // 4. 生成自动优化建议
            List<OptimizationSuggestion> autoSuggestions = generateAutoOptimizationSuggestions(prediction);

            // 5. 应用自动优化建议
            applyAutoOptimizationSuggestions(autoSuggestions);

            log.info("SLB性能自动优化完成");

        } catch (Exception e) {
            log.error("SLB性能自动优化失败", e);
            throw new SLBAutoOptimizationException("SLB性能自动优化失败", e);
        }
    }

    /**
     * 优化负载均衡算法
     */
    public void optimizeLoadBalancingAlgorithm() {
        try {
            // 1. 分析当前算法性能
            LoadBalancingAlgorithmAnalysis algorithmAnalysis = performanceAnalyzer.analyzeLoadBalancingAlgorithm();

            // 2. 选择最优算法
            String optimalAlgorithm = selectOptimalAlgorithm(algorithmAnalysis);

            // 3. 应用最优算法
            applyOptimalAlgorithm(optimalAlgorithm);

            log.info("负载均衡算法优化完成: {}", optimalAlgorithm);

        } catch (Exception e) {
            log.error("负载均衡算法优化失败", e);
            throw new LoadBalancingAlgorithmOptimizationException("负载均衡算法优化失败", e);
        }
    }

    /**
     * 优化健康检查配置
     */
    public void optimizeHealthCheckConfig() {
        try {
            // 1. 分析健康检查性能
            HealthCheckPerformanceAnalysis healthCheckAnalysis = performanceAnalyzer.analyzeHealthCheckPerformance();

            // 2. 计算最优健康检查配置
            OptimalHealthCheckConfig optimalConfig = calculateOptimalHealthCheckConfig(healthCheckAnalysis);

            // 3. 应用最优健康检查配置
            applyOptimalHealthCheckConfig(optimalConfig);

            log.info("健康检查配置优化完成");

        } catch (Exception e) {
            log.error("健康检查配置优化失败", e);
            throw new HealthCheckConfigOptimizationException("健康检查配置优化失败", e);
        }
    }

    /**
     * 生成优化建议
     */
    private List<OptimizationSuggestion> generateOptimizationSuggestions(SLBPerformanceAnalysis analysis) {
        List<OptimizationSuggestion> suggestions = new ArrayList<>();

        // 负载均衡算法优化建议
        if (analysis.getAlgorithmEfficiency() < 0.8) {
            OptimizationSuggestion suggestion = new OptimizationSuggestion();
            suggestion.setType(OptimizationType.LOAD_BALANCING_ALGORITHM);
            suggestion.setPriority(Priority.HIGH);
            suggestion.setTitle("优化负载均衡算法");
            suggestion.setDescription("当前负载均衡算法效率较低，建议更换算法");
            suggestion.setCurrentValue(analysis.getCurrentAlgorithm());
            suggestion.setSuggestedValue("LEAST_CONNECTIONS");
            suggestions.add(suggestion);
        }

        // 健康检查优化建议
        if (analysis.getHealthCheckOverhead() > 0.1) {
            OptimizationSuggestion suggestion = new OptimizationSuggestion();
            suggestion.setType(OptimizationType.HEALTH_CHECK);
            suggestion.setPriority(Priority.MEDIUM);
            suggestion.setTitle("优化健康检查配置");
            suggestion.setDescription("健康检查开销过大，建议调整检查间隔");
            suggestion.setCurrentValue(analysis.getHealthCheckInterval());
            suggestion.setSuggestedValue(analysis.getHealthCheckInterval() * 2);
            suggestions.add(suggestion);
        }

        // 会话保持优化建议
        if (analysis.getSessionPersistenceOverhead() > 0.05) {
            OptimizationSuggestion suggestion = new OptimizationSuggestion();
            suggestion.setType(OptimizationType.SESSION_PERSISTENCE);
            suggestion.setPriority(Priority.LOW);
            suggestion.setTitle("优化会话保持配置");
            suggestion.setDescription("会话保持开销较大，建议调整超时时间");
            suggestion.setCurrentValue(analysis.getSessionTimeout());
            suggestion.setSuggestedValue(analysis.getSessionTimeout() / 2);
            suggestions.add(suggestion);
        }

        return suggestions;
    }

    /**
     * 应用优化建议
     */
    private void applyOptimizationSuggestions(List<OptimizationSuggestion> suggestions) {
        for (OptimizationSuggestion suggestion : suggestions) {
            try {
                switch (suggestion.getType()) {
                    case LOAD_BALANCING_ALGORITHM:
                        applyLoadBalancingAlgorithmOptimization(suggestion);
                        break;
                    case HEALTH_CHECK:
                        applyHealthCheckOptimization(suggestion);
                        break;
                    case SESSION_PERSISTENCE:
                        applySessionPersistenceOptimization(suggestion);
                        break;
                    default:
                        log.warn("未知的优化类型: {}", suggestion.getType());
                }

                log.info("应用优化建议: {}", suggestion.getTitle());

            } catch (Exception e) {
                log.error("应用优化建议失败: {}", suggestion.getTitle(), e);
            }
        }
    }

    /**
     * 选择最优算法
     */
    private String selectOptimalAlgorithm(LoadBalancingAlgorithmAnalysis analysis) {
        // 基于分析结果选择最优算法
        if (analysis.getConnectionDistribution() > 0.8) {
            return "LEAST_CONNECTIONS";
        } else if (analysis.getSessionAffinity() > 0.7) {
            return "SOURCE_IP_HASH";
        } else if (analysis.getServerWeightVariation() > 0.5) {
            return "WEIGHTED_ROUND_ROBIN";
        } else {
            return "ROUND_ROBIN";
        }
    }

    /**
     * 应用最优算法
     */
    private void applyOptimalAlgorithm(String algorithm) {
        try {
            // 获取当前配置
            SLBConfig config = configManagementService.getSLBConfig("default");

            // 更新算法配置
            config.setLoadBalancingAlgorithm(algorithm);

            // 保存配置
            configManagementService.updateSLBConfig("default", config);

        } catch (Exception e) {
            log.error("应用最优算法失败: {}", algorithm, e);
            throw new AlgorithmApplicationException("应用最优算法失败", e);
        }
    }

    /**
     * 计算最优健康检查配置
     */
    private OptimalHealthCheckConfig calculateOptimalHealthCheckConfig(HealthCheckPerformanceAnalysis analysis) {
        OptimalHealthCheckConfig optimalConfig = new OptimalHealthCheckConfig();

        // 基于性能分析计算最优配置
        long optimalInterval = Math.max(analysis.getCurrentInterval() * 2, 30000); // 最小30秒
        optimalInterval = Math.min(optimalInterval, 300000); // 最大5分钟

        int optimalTimeout = Math.max(analysis.getCurrentTimeout() / 2, 3000); // 最小3秒
        optimalTimeout = Math.min(optimalTimeout, 30000); // 最大30秒

        optimalConfig.setCheckInterval(optimalInterval);
        optimalConfig.setTimeout(optimalTimeout);
        optimalConfig.setRetryCount(3);
        optimalConfig.setSuccessThreshold(2);
        optimalConfig.setFailureThreshold(3);

        return optimalConfig;
    }

    /**
     * 应用最优健康检查配置
     */
    private void applyOptimalHealthCheckConfig(OptimalHealthCheckConfig optimalConfig) {
        try {
            // 获取当前配置
            SLBConfig config = configManagementService.getSLBConfig("default");

            // 更新健康检查配置
            HealthCheckConfig healthCheckConfig = config.getHealthCheckConfig();
            healthCheckConfig.setCheckInterval(optimalConfig.getCheckInterval());
            healthCheckConfig.setTimeout(optimalConfig.getTimeout());
            healthCheckConfig.setRetryCount(optimalConfig.getRetryCount());
            healthCheckConfig.setSuccessThreshold(optimalConfig.getSuccessThreshold());
            healthCheckConfig.setFailureThreshold(optimalConfig.getFailureThreshold());

            // 保存配置
            configManagementService.updateSLBConfig("default", config);

        } catch (Exception e) {
            log.error("应用最优健康检查配置失败", e);
            throw new HealthCheckConfigApplicationException("应用最优健康检查配置失败", e);
        }
    }
}

六、最佳实践与总结

6.1 负载均衡SLB最佳实践

负载均衡算法选择
- 根据应用特性选择合适的算法
- 考虑服务器性能和权重
- 平衡负载分布和会话保持
健康检查配置
- 合理设置检查间隔和超时时间
- 选择合适的检查类型和路径
- 配置合理的成功和失败阈值
会话保持策略
- 根据应用需求选择保持方式
- 合理设置会话超时时间
- 考虑服务器故障时的会话迁移
安全防护机制
- 启用DDoS防护和WAF
- 配置SSL卸载和访问控制
- 建立完善的安全监控体系

6.2 架构师级SLB运维技能

负载均衡管理能力
- 深入理解SLB架构和原理
- 掌握各种负载均衡算法
- 管理后端服务器和健康检查
性能调优能力
- 优化负载均衡算法
- 调整健康检查配置
- 优化会话保持策略
故障处理能力
- 快速定位SLB问题
- 制定修复方案
- 预防潜在问题
监控运维能力
- 建立监控体系
- 实现自动化运维
- 持续优化改进

6.3 持续改进建议

性能优化
- 持续优化负载均衡算法
- 改进健康检查策略
- 提升整体性能
自动化程度提升
- 实现更多自动化操作
- 优化配置管理流程
- 提升运维效率
知识积累
- 建立运维知识库
- 总结最佳实践
- 形成标准化流程

总结

负载均衡SLB是企业级高可用架构的核心组件，通过智能的流量分发策略、完善的健康检查机制和系统化的安全防护，能够构建稳定可靠的负载均衡系统，保障企业级应用的高并发处理能力。本文从负载均衡架构设计到智能调度，从基础原理到企业级实践，系统梳理了负载均衡SLB的完整解决方案。

关键要点：

负载均衡架构设计：高可用的SLB架构和组件设计
流量分发策略：多种负载均衡算法和智能调度
健康检查机制：完善的健康检查和监控体系
会话保持方案：灵活的会话保持和安全防护
企业级实践：配置管理、性能优化、持续改进

通过深入理解这些技术要点，架构师能够设计出完善的负载均衡SLB系统，提升系统的可用性和性能，确保企业级应用的高可用性。