diff --git a/backend/pom.xml b/backend/pom.xml
index 93fade5a..324bb058 100644
--- a/backend/pom.xml
+++ b/backend/pom.xml
@@ -282,11 +282,24 @@
             <version>5.0.1</version>
         </dependency>
         
-        <!-- Kubernetes Java Client (支持K8S 1.23-1.28) -->
+        <!-- Kubernetes Java Client (支持K8S 1.23-1.29+) -->
         <dependency>
             <groupId>io.kubernetes</groupId>
             <artifactId>client-java</artifactId>
-            <version>18.0.1</version>
+            <version>21.0.2-legacy</version>
+        </dependency>
+        
+        <!-- 覆盖 kubernetes-client 的 OkHttp 版本，使用 5.x 以支持虚拟线程 -->
+        <!-- OkHttp 5.x 内部将 synchronized 改为 Lock/Condition，避免虚拟线程 pinning 和 HTTP/2 死锁 -->
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>okhttp</artifactId>
+            <version>5.0.0-alpha.14</version>
+        </dependency>
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>logging-interceptor</artifactId>
+            <version>5.0.0-alpha.14</version>
         </dependency>
     </dependencies>
 
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/integration/impl/K8sServiceIntegrationImpl.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/integration/impl/K8sServiceIntegrationImpl.java
index d1222a35..bfa4d679 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/integration/impl/K8sServiceIntegrationImpl.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/integration/impl/K8sServiceIntegrationImpl.java
@@ -146,7 +146,7 @@ public class K8sServiceIntegrationImpl extends BaseExternalSystemIntegration imp
             CoreV1Api api = new CoreV1Api(cache.apiClient);
 
             V1NamespaceList namespaceList = api.listNamespace(
-                null, null, null, null, null, null, null, null, null, null
+                null, null, null, null, null, null, null, null, null, null, null
             );
 
             List<K8sNamespaceResponse> namespaces = new ArrayList<>();
@@ -200,7 +200,7 @@ public class K8sServiceIntegrationImpl extends BaseExternalSystemIntegration imp
             AppsV1Api api = new AppsV1Api(cache.apiClient);
 
             V1DeploymentList deploymentList = api.listNamespacedDeployment(
-                namespace, null, null, null, null, null, null, null, null, null, null
+                namespace, null, null, null, null, null, null, null, null, null, null, null
             );
 
             List<K8sDeploymentResponse> deployments = new ArrayList<>();
@@ -279,7 +279,7 @@ public class K8sServiceIntegrationImpl extends BaseExternalSystemIntegration imp
             AppsV1Api api = new AppsV1Api(cache.apiClient);
 
             V1DeploymentList deploymentList = api.listDeploymentForAllNamespaces(
-                null, null, null, null, null, null, null, null, null, null
+                null, null, null, null, null, null, null, null, null, null, null
             );
 
             List<K8sDeploymentResponse> deployments = new ArrayList<>();
@@ -357,7 +357,7 @@ public class K8sServiceIntegrationImpl extends BaseExternalSystemIntegration imp
             CoreV1Api api = new CoreV1Api(cache.apiClient);
 
             V1PodList podList = api.listNamespacedPod(
-                namespace, null, null, null, null, null, null, null, null, null, null
+                namespace, null, null, null, null, null, null, null, null, null, null, null
             );
 
             List<K8sPodResponse> pods = new ArrayList<>();
@@ -406,7 +406,7 @@ public class K8sServiceIntegrationImpl extends BaseExternalSystemIntegration imp
             // 3. 使用label selector查询Pod
             CoreV1Api coreApi = new CoreV1Api(cache.apiClient);
             V1PodList podList = coreApi.listNamespacedPod(
-                namespace, null, null, null, null, labelSelector, null, null, null, null, null
+                namespace, null, null, null, null, labelSelector, null, null, null, null, null, null
             );
 
             List<K8sPodResponse> pods = new ArrayList<>();
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ExternalSystemHealthCheckScheduler.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ExternalSystemHealthCheckScheduler.java
index ffb10f00..63ecef91 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ExternalSystemHealthCheckScheduler.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ExternalSystemHealthCheckScheduler.java
@@ -22,6 +22,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 
 /**
@@ -60,6 +61,9 @@ public class ExternalSystemHealthCheckScheduler {
     private static final String FAILURE_COUNT_KEY_PREFIX = "external_system:failure_count:";
     private static final long FAILURE_COUNT_TTL_SECONDS = 5 * 60; // 失败计数过期时间（秒）
 
+    // 防重复执行标记
+    private final AtomicBoolean isRunning = new AtomicBoolean(false);
+
     /**
      * 检查所有外部系统的健康状态
      * 此方法由定时任务管理系统调用
@@ -69,6 +73,24 @@ public class ExternalSystemHealthCheckScheduler {
      */
     public void checkExternalSystemsHealth(Long notificationChannelId,
                                           Long resourceAlertTemplateId) {
+        // 防止重复执行：如果上一次检查还在执行中，跳过本次
+        if (!isRunning.compareAndSet(false, true)) {
+            log.warn("上一次外部系统健康检查任务仍在执行中，跳过本次执行");
+            return;
+        }
+
+        try {
+            doCheckExternalSystemsHealth(notificationChannelId, resourceAlertTemplateId);
+        } finally {
+            isRunning.set(false);
+        }
+    }
+
+    /**
+     * 执行健康检查的核心逻辑
+     */
+    private void doCheckExternalSystemsHealth(Long notificationChannelId,
+                                              Long resourceAlertTemplateId) {
         // 构建通知配置对象
         final ServerMonitorNotificationConfig config;
         if (notificationChannelId != null) {
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ServerMonitorScheduler.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ServerMonitorScheduler.java
index 4d80d8fc..bb36d581 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ServerMonitorScheduler.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/scheduler/ServerMonitorScheduler.java
@@ -32,6 +32,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 
 /**
@@ -67,6 +68,9 @@ public class ServerMonitorScheduler {
     @Qualifier("serverMonitorExecutor")
     private Executor serverMonitorExecutor;
 
+    // 防重复执行标记
+    private final AtomicBoolean isRunning = new AtomicBoolean(false);
+
     /**
      * 采集所有在线服务器的监控数据
      * 此方法由定时任务管理系统调用
@@ -76,6 +80,24 @@ public class ServerMonitorScheduler {
      */
     public void collectServerMetrics(Long notificationChannelId,
                                      Long resourceAlertTemplateId) {
+        // 防止重复执行：如果上一次采集还在执行中，跳过本次
+        if (!isRunning.compareAndSet(false, true)) {
+            log.warn("上一次服务器监控采集任务仍在执行中，跳过本次执行");
+            return;
+        }
+
+        try {
+            doCollectServerMetrics(notificationChannelId, resourceAlertTemplateId);
+        } finally {
+            isRunning.set(false);
+        }
+    }
+
+    /**
+     * 执行服务器监控采集的核心逻辑
+     */
+    private void doCollectServerMetrics(Long notificationChannelId,
+                                        Long resourceAlertTemplateId) {
         // 构建通知配置对象
         ServerMonitorNotificationConfig config = null;
         if (notificationChannelId != null) {
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/K8sDeploymentServiceImpl.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/K8sDeploymentServiceImpl.java
index fdaf9764..d3830051 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/K8sDeploymentServiceImpl.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/K8sDeploymentServiceImpl.java
@@ -33,7 +33,10 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.stream.Collectors;
 
 @Slf4j
@@ -249,12 +252,31 @@ public class K8sDeploymentServiceImpl extends BaseServiceImpl<K8sDeployment, K8s
                 futures.toArray(new CompletableFuture[0])
             );
             
-            // 阻塞等待所有任务完成
-            allFutures.join();
+            // 阻塞等待所有任务完成（最多5分钟超时）
+            try {
+                allFutures.get(5, TimeUnit.MINUTES);
+            } catch (TimeoutException e) {
+                log.error("K8S Deployment同步超时（5分钟）", e);
+                futures.forEach(f -> f.cancel(true));
+                throw new BusinessException(ResponseCode.K8S_DEPLOYMENT_SYNC_FAILED);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new BusinessException(ResponseCode.K8S_DEPLOYMENT_SYNC_FAILED);
+            } catch (ExecutionException e) {
+                log.error("K8S Deployment同步执行异常", e);
+                throw new BusinessException(ResponseCode.K8S_DEPLOYMENT_SYNC_FAILED);
+            }
             
             // 汇总同步数量
             int totalSyncCount = futures.stream()
-                .map(CompletableFuture::join)
+                .filter(f -> !f.isCancelled() && f.isDone())
+                .map(f -> {
+                    try {
+                        return f.getNow(0);
+                    } catch (Exception e) {
+                        return 0;
+                    }
+                })
                 .mapToInt(Integer::intValue)
                 .sum();
             
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryBranchServiceImpl.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryBranchServiceImpl.java
index a45c4749..11ae01f5 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryBranchServiceImpl.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryBranchServiceImpl.java
@@ -34,6 +34,9 @@ import java.util.Map;
 import java.util.ArrayList;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -349,9 +352,31 @@ public class RepositoryBranchServiceImpl extends BaseServiceImpl<RepositoryBranc
                 futures.add(future);
             }
 
-            // 6. 等待所有异步任务完成并收集结果
+            // 6. 等待所有异步任务完成并收集结果（最多5分钟超时）
+            CompletableFuture<Void> allFutures = CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]));
+            try {
+                allFutures.get(5, TimeUnit.MINUTES);
+            } catch (TimeoutException e) {
+                log.error("分支同步超时（5分钟）", e);
+                futures.forEach(f -> f.cancel(true));
+                throw new BusinessException(ResponseCode.REPOSITORY_BRANCH_SYNC_FAILED);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new BusinessException(ResponseCode.REPOSITORY_BRANCH_SYNC_FAILED);
+            } catch (ExecutionException e) {
+                log.error("分支同步执行异常", e);
+                throw new BusinessException(ResponseCode.REPOSITORY_BRANCH_SYNC_FAILED);
+            }
+            
             List<RepositoryBranch> allBranchesToSave = futures.stream()
-                .map(CompletableFuture::join)
+                .filter(f -> !f.isCancelled() && f.isDone())
+                .map(f -> {
+                    try {
+                        return f.getNow(List.of());
+                    } catch (Exception e) {
+                        return List.<RepositoryBranch>of();
+                    }
+                })
                 .flatMap(List::stream)
                 .collect(Collectors.toList());
 
diff --git a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryProjectServiceImpl.java b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryProjectServiceImpl.java
index 84d9e9aa..0248d356 100644
--- a/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryProjectServiceImpl.java
+++ b/backend/src/main/java/com/qqchen/deploy/backend/deploy/service/impl/RepositoryProjectServiceImpl.java
@@ -43,6 +43,9 @@ import java.util.ArrayList;
 import java.util.concurrent.CompletionException;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.Collections;
 
@@ -255,8 +258,20 @@ public class RepositoryProjectServiceImpl extends BaseServiceImpl<RepositoryProj
                 futures.add(future);
             }
 
-            // 等待所有异步任务完成
-            CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();
+            // 等待所有异步任务完成（最多5分钟超时）
+            try {
+                CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).get(5, TimeUnit.MINUTES);
+            } catch (TimeoutException e) {
+                log.error("项目同步超时（5分钟）", e);
+                futures.forEach(f -> f.cancel(true));
+                throw new BusinessException(ResponseCode.REPOSITORY_PROJECT_SYNC_FAILED);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new BusinessException(ResponseCode.REPOSITORY_PROJECT_SYNC_FAILED);
+            } catch (ExecutionException e) {
+                log.error("项目同步执行异常", e);
+                throw new BusinessException(ResponseCode.REPOSITORY_PROJECT_SYNC_FAILED);
+            }
 
             // 批量保存项目
             if (!projectsToSave.isEmpty()) {