diff --git a/ansible/mysql-deploy-callback.yml b/ansible/mysql-deploy-callback.yml
index 945d3f9..ae46d03 100644
--- a/ansible/mysql-deploy-callback.yml
+++ b/ansible/mysql-deploy-callback.yml
@@ -61,7 +61,13 @@
     mgr_group_name: "{{ group_replication_group_name | default('aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa') }}"
 
     # --- expected node count per topology ---
-    mysql_expected_hosts: "{{ {'standalone': 1, 'primary_replica': 2, 'mgr_3': 3}[topology | default('standalone')] }}"
+    mysql_expected_hosts: "{{ 1 if (topology | default('standalone')) == 'standalone' else ((replica_count | default(1) | int) + 1 if (topology | default('standalone')) == 'primary_replica' else 3) }}"
+    # 平台为 primary_replica 显式传入主从节点；standalone 仍按旧逻辑工作。
+    mysql_primary_host_value: "{{ mysql_primary_host | default(ansible_play_hosts_all[0]) }}"
+    mysql_primary_ip_value: "{{ mysql_primary_ip | default(hostvars[mysql_primary_host_value].ansible_host | default(mysql_primary_host_value)) }}"
+    # 交付只暴露 root 管理员；复制链路复用已配置好的 root@%。
+    mysql_replication_user: "root"
+    mysql_replication_password: "{{ mysql_root_password_value }}"
 
     # --- secrets (prefer launch extra_vars; fall back to AWX credential-injected env) ---
     mysql_root_password_value: "{{ mysql_root_password | default(lookup('ansible.builtin.env', 'XINFRA_MYSQL_ROOT_PASSWORD'), true) }}"
@@ -355,7 +361,7 @@
         mysql_node_index: "{{ ansible_play_hosts_all.index(inventory_hostname) }}"
         mysql_node_role: >-
           {{ 'standalone' if topology == 'standalone' else
-             ('primary' if ansible_play_hosts_all.index(inventory_hostname) == 0 else
+             ('primary' if inventory_hostname == mysql_primary_host_value else
              ('replica' if topology == 'primary_replica' else 'mgr')) }}
         # host-wide unique: platform may pass explicit mysql_server_id; otherwise derive
         # port + node index (ports are unique per host in the pool model).
@@ -446,15 +452,27 @@
           EOF
           if ! /usr/bin/mysql --defaults-extra-file="$client_file" -e 'SELECT 1' >/dev/null 2>&1; then
             cat >"$sql_file" <<'EOF'
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL super_read_only = OFF;
+          SET GLOBAL read_only = OFF;
+          {% endif %}
           ALTER USER 'root'@'localhost' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           EOF
             /usr/bin/mysql --protocol=socket --socket={{ mysql_run_dir }}/mysql.sock -uroot <"$sql_file"
           fi
           cat >"$sql_file" <<'EOF'
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL super_read_only = OFF;
+          SET GLOBAL read_only = OFF;
+          {% endif %}
           CREATE USER IF NOT EXISTS 'root'@'%' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           ALTER USER 'root'@'%' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
           FLUSH PRIVILEGES;
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL read_only = ON;
+          SET GLOBAL super_read_only = ON;
+          {% endif %}
           EOF
           /usr/bin/mysql --defaults-extra-file="$client_file" <"$sql_file"
         executable: /bin/bash
@@ -479,6 +497,64 @@
       failed_when: false
       no_log: true
 
+    - name: Wait for the replica to reach the primary SQL port
+      ansible.builtin.wait_for:
+        host: "{{ mysql_primary_ip_value }}"
+        port: "{{ mysql_port_value }}"
+        timeout: 60
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+
+    - name: Configure and start GTID replication on the replica
+      ansible.builtin.shell:
+        cmd: |
+          set -euo pipefail
+          client_file="$(mktemp)"
+          sql_file="$(mktemp)"
+          trap 'rm -f "$client_file" "$sql_file"' EXIT
+          chmod 600 "$client_file" "$sql_file"
+          cat >"$client_file" <<'EOF'
+          [client]
+          user=root
+          password={{ mysql_root_password_value }}
+          socket={{ mysql_run_dir }}/mysql.sock
+          EOF
+          cat >"$sql_file" <<'EOF'
+          STOP REPLICA;
+          RESET REPLICA ALL;
+          CHANGE REPLICATION SOURCE TO SOURCE_HOST='{{ mysql_primary_ip_value }}', SOURCE_PORT={{ mysql_port_value }}, SOURCE_USER='{{ mysql_replication_user }}', SOURCE_PASSWORD='{{ mysql_replication_password | replace("'", "''") }}', SOURCE_AUTO_POSITION=1, GET_SOURCE_PUBLIC_KEY=1;
+          START REPLICA;
+          EOF
+          /usr/bin/mysql --defaults-extra-file="$client_file" <"$sql_file"
+        executable: /bin/bash
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+      no_log: true
+
+    - name: Verify GTID replication threads
+      ansible.builtin.shell:
+        cmd: |
+          set -euo pipefail
+          client_file="$(mktemp)"
+          trap 'rm -f "$client_file"' EXIT
+          chmod 600 "$client_file"
+          cat >"$client_file" <<'EOF'
+          [client]
+          user=root
+          password={{ mysql_root_password_value }}
+          socket={{ mysql_run_dir }}/mysql.sock
+          EOF
+          status="$(/usr/bin/mysql --defaults-extra-file="$client_file" -e 'SHOW REPLICA STATUS\G')"
+          grep -q 'Replica_IO_Running: Yes' <<<"$status"
+          grep -q 'Replica_SQL_Running: Yes' <<<"$status"
+          grep -qE '^[[:space:]]*Last_IO_Error:[[:space:]]*$' <<<"$status"
+          grep -qE '^[[:space:]]*Last_SQL_Error:[[:space:]]*$' <<<"$status"
+        executable: /bin/bash
+      register: mysql_replica_status
+      retries: 12
+      delay: 5
+      until: mysql_replica_status.rc == 0
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+      no_log: true
+
     - name: Notify healthcheck started
       ansible.builtin.uri:
         url: "{{ delivery_callback_url_value }}"
@@ -521,13 +597,10 @@
       failed_when: false
       no_log: true
 
-    - name: Note pending HA runtime orchestration
+    - name: Note pending Group Replication orchestration
       ansible.builtin.debug:
-        msg: >-
-          topology={{ topology }} deployed with HA-ready config (GTID/binlog/relay/GR settings in place),
-          but replication wiring (CHANGE REPLICATION SOURCE) and Group Replication bootstrap
-          (START GROUP_REPLICATION) are not yet automated — nodes start config-ready only.
-      when: topology != 'standalone'
+        msg: "MGR remains unsupported; primary_replica GTID replication is configured and healthy."
+      when: topology == 'mgr_3'
       run_once: true
 
     - name: Notify platform registration handoff
diff --git a/ansible/mysql-deploy.yml b/ansible/mysql-deploy.yml
index ad5f69d..d59a54b 100644
--- a/ansible/mysql-deploy.yml
+++ b/ansible/mysql-deploy.yml
@@ -61,7 +61,13 @@
     mgr_group_name: "{{ group_replication_group_name | default('aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa') }}"
 
     # --- expected node count per topology ---
-    mysql_expected_hosts: "{{ {'standalone': 1, 'primary_replica': 2, 'mgr_3': 3}[topology | default('standalone')] }}"
+    mysql_expected_hosts: "{{ 1 if (topology | default('standalone')) == 'standalone' else ((replica_count | default(1) | int) + 1 if (topology | default('standalone')) == 'primary_replica' else 3) }}"
+    # 平台为 primary_replica 显式传入主从节点；standalone 仍按旧逻辑工作。
+    mysql_primary_host_value: "{{ mysql_primary_host | default(ansible_play_hosts_all[0]) }}"
+    mysql_primary_ip_value: "{{ mysql_primary_ip | default(hostvars[mysql_primary_host_value].ansible_host | default(mysql_primary_host_value)) }}"
+    # 交付只暴露 root 管理员；复制链路复用已配置好的 root@%。
+    mysql_replication_user: "root"
+    mysql_replication_password: "{{ mysql_root_password_value }}"
 
     # --- secrets (prefer launch extra_vars; fall back to AWX credential-injected env) ---
     mysql_root_password_value: "{{ mysql_root_password | default(lookup('ansible.builtin.env', 'XINFRA_MYSQL_ROOT_PASSWORD'), true) }}"
@@ -258,7 +264,7 @@
         mysql_node_index: "{{ ansible_play_hosts_all.index(inventory_hostname) }}"
         mysql_node_role: >-
           {{ 'standalone' if topology == 'standalone' else
-             ('primary' if ansible_play_hosts_all.index(inventory_hostname) == 0 else
+             ('primary' if inventory_hostname == mysql_primary_host_value else
              ('replica' if topology == 'primary_replica' else 'mgr')) }}
         # host-wide unique: platform may pass explicit mysql_server_id; otherwise derive
         # port + node index (ports are unique per host in the pool model).
@@ -349,34 +355,101 @@
           EOF
           if ! /usr/bin/mysql --defaults-extra-file="$client_file" -e 'SELECT 1' >/dev/null 2>&1; then
             cat >"$sql_file" <<'EOF'
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL super_read_only = OFF;
+          SET GLOBAL read_only = OFF;
+          {% endif %}
           ALTER USER 'root'@'localhost' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           EOF
             /usr/bin/mysql --protocol=socket --socket={{ mysql_run_dir }}/mysql.sock -uroot <"$sql_file"
           fi
           cat >"$sql_file" <<'EOF'
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL super_read_only = OFF;
+          SET GLOBAL read_only = OFF;
+          {% endif %}
           CREATE USER IF NOT EXISTS 'root'@'%' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           ALTER USER 'root'@'%' IDENTIFIED BY '{{ mysql_root_password_value | replace("'", "''") }}';
           GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
           FLUSH PRIVILEGES;
+          {% if topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value %}
+          SET GLOBAL read_only = ON;
+          SET GLOBAL super_read_only = ON;
+          {% endif %}
           EOF
           /usr/bin/mysql --defaults-extra-file="$client_file" <"$sql_file"
         executable: /bin/bash
       changed_when: false
       no_log: true
 
-    - name: Verify MySQL TCP health
+    - name: Wait for the replica to reach the primary SQL port
+      ansible.builtin.wait_for:
+        host: "{{ mysql_primary_ip_value }}"
+        port: "{{ mysql_port_value }}"
+        timeout: 60
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+
+    - name: Configure and start GTID replication on the replica
+      ansible.builtin.shell:
+        cmd: |
+          set -euo pipefail
+          client_file="$(mktemp)"
+          sql_file="$(mktemp)"
+          trap 'rm -f "$client_file" "$sql_file"' EXIT
+          chmod 600 "$client_file" "$sql_file"
+          cat >"$client_file" <<'EOF'
+          [client]
+          user=root
+          password={{ mysql_root_password_value }}
+          socket={{ mysql_run_dir }}/mysql.sock
+          EOF
+          cat >"$sql_file" <<'EOF'
+          STOP REPLICA;
+          RESET REPLICA ALL;
+          CHANGE REPLICATION SOURCE TO SOURCE_HOST='{{ mysql_primary_ip_value }}', SOURCE_PORT={{ mysql_port_value }}, SOURCE_USER='{{ mysql_replication_user }}', SOURCE_PASSWORD='{{ mysql_replication_password | replace("'", "''") }}', SOURCE_AUTO_POSITION=1, GET_SOURCE_PUBLIC_KEY=1;
+          START REPLICA;
+          EOF
+          /usr/bin/mysql --defaults-extra-file="$client_file" <"$sql_file"
+        executable: /bin/bash
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+      no_log: true
+
+    - name: Verify GTID replication threads
+      ansible.builtin.shell:
+        cmd: |
+          set -euo pipefail
+          client_file="$(mktemp)"
+          trap 'rm -f "$client_file"' EXIT
+          chmod 600 "$client_file"
+          cat >"$client_file" <<'EOF'
+          [client]
+          user=root
+          password={{ mysql_root_password_value }}
+          socket={{ mysql_run_dir }}/mysql.sock
+          EOF
+          status="$(/usr/bin/mysql --defaults-extra-file="$client_file" -e 'SHOW REPLICA STATUS\G')"
+          grep -q 'Replica_IO_Running: Yes' <<<"$status"
+          grep -q 'Replica_SQL_Running: Yes' <<<"$status"
+          grep -qE '^[[:space:]]*Last_IO_Error:[[:space:]]*$' <<<"$status"
+          grep -qE '^[[:space:]]*Last_SQL_Error:[[:space:]]*$' <<<"$status"
+        executable: /bin/bash
+      register: mysql_replica_status
+      retries: 12
+      delay: 5
+      until: mysql_replica_status.rc == 0
+      when: topology == 'primary_replica' and inventory_hostname != mysql_primary_host_value
+      no_log: true
+
+    - name: Verify MySQL TCP health on every node
       ansible.builtin.wait_for:
         host: "{{ ansible_host | default(inventory_hostname) }}"
         port: "{{ mysql_port_value }}"
         timeout: 30
 
-    - name: Note pending HA runtime orchestration
+    - name: Note pending Group Replication orchestration
       ansible.builtin.debug:
-        msg: >-
-          topology={{ topology }} deployed with HA-ready config (GTID/binlog/relay/GR settings in place),
-          but replication wiring (CHANGE REPLICATION SOURCE) and Group Replication bootstrap
-          (START GROUP_REPLICATION) are not yet automated — nodes start config-ready only.
-      when: topology != 'standalone'
+        msg: "MGR remains unsupported; primary_replica GTID replication is configured and healthy."
+      when: topology == 'mgr_3'
       run_once: true
 
   handlers:
diff --git a/ansible/templates/mysql-instance.cnf.j2 b/ansible/templates/mysql-instance.cnf.j2
index fc3918c..fffb5be 100644
--- a/ansible/templates/mysql-instance.cnf.j2
+++ b/ansible/templates/mysql-instance.cnf.j2
@@ -53,6 +53,12 @@ binlog-expire-logs-seconds={{ mysql_binlog_expire_logs_seconds }} # binlog 过
 gtid-mode=ON                                             # 启用 GTID（全局事务标识符）
 enforce-gtid-consistency=ON                              # 强制 GTID 一致性（确保复制安全）
 relay-log={{ mysql_binlog_dir }}/relay-bin               # 中继日志路径（从库重放 binlog 使用）
+{% if mysql_node_role | default('') == 'replica' %}
+# 从库强制只读：阻止业务直接写入从库导致主从数据分叉
+# 复制线程与 CHANGE REPLICATION SOURCE 等复制管理语句不受影响
+read-only=ON
+super-read-only=ON
+{% endif %}
 {% endif %}
 
 # =============================================================================
diff --git a/frontend/src/api/delivery.ts b/frontend/src/api/delivery.ts
index 5698b03..9aa1180 100644
--- a/frontend/src/api/delivery.ts
+++ b/frontend/src/api/delivery.ts
@@ -25,9 +25,11 @@ export interface CreateMySQLDeliveryPayload {
   instance_name: string
   mysql_version: string
   topology: string
+  replica_count?: number
   mysql_port?: number
   data_disk: string
   target_host?: string
+  target_hosts?: string[]
   cpu_milli: number
   memory_mi: number
   storage_gi: number
@@ -77,6 +79,8 @@ export interface DeliveryTask {
   instance_name: string
   target_host?: string
   target_host_ip?: string
+  target_hosts?: string
+  target_host_ips?: string
   mysql_port?: number
   postgresql_port?: number
   status: string
diff --git a/frontend/src/views/service/Catalog.vue b/frontend/src/views/service/Catalog.vue
index 1b84470..4ac0e52 100644
--- a/frontend/src/views/service/Catalog.vue
+++ b/frontend/src/views/service/Catalog.vue
@@ -101,9 +101,9 @@
                   </el-select>
                 </label>
                 <label class="form-field">
-                  {{ isPostgreSQL && deliveryForm.mode === 'primary_replica' ? '部署主机（按角色顺序）' : '部署主机' }}
+                  {{ (isPostgreSQL && deliveryForm.mode === 'primary_replica') || (activeServiceKey === 'mysql' && deliveryForm.mode === 'replica') ? '部署主机（按角色顺序）' : '部署主机' }}
                   <el-select
-                    v-if="isPostgreSQL && deliveryForm.mode === 'primary_replica'"
+                    v-if="(isPostgreSQL && deliveryForm.mode === 'primary_replica') || (activeServiceKey === 'mysql' && deliveryForm.mode === 'replica')"
                     v-model="deliveryForm.targetHosts"
                     multiple
                     :multiple-limit="deliveryForm.replicaCount + 1"
@@ -116,7 +116,7 @@
                     <el-option v-for="host in targetHosts" :key="host.name" :label="hostLabel(host)" :value="host.name" />
                   </el-select>
                 </label>
-                <label v-if="isPostgreSQL && deliveryForm.mode === 'primary_replica'" class="form-field">
+                <label v-if="(isPostgreSQL && deliveryForm.mode === 'primary_replica') || (activeServiceKey === 'mysql' && deliveryForm.mode === 'replica')" class="form-field">
                   从节点数量
                   <el-input-number v-model="deliveryForm.replicaCount" :min="1" :max="7" controls-position="right" />
                   <small class="field-help">需要 {{ deliveryForm.replicaCount + 1 }} 台不同主机；当前模板可用 {{ targetHosts.length }} 台。</small>
@@ -334,8 +334,14 @@
               <div><span>数据位置</span><strong>{{ deliveryForm.dataDisk }}</strong></div>
             </div>
 
-            <div class="topology" :class="`nodes-${topologyNodes.length}`">
-              <div v-for="node in topologyNodes" :key="node.name" class="node-card">
+            <div class="topology-shell" :class="{ 'is-replica': topologyNodes.length > 1 }">
+              <div class="topology-title">
+                <strong>{{ topologyNodes.length }} 节点{{ topologyNodes.length > 1 ? `（1 主 ${topologyNodes.length - 1} 从）` : '' }}</strong>
+                <span>{{ topologyNodes.length > 1 ? 'GTID 异步复制 · 从节点默认只读' : '单实例部署' }}</span>
+              </div>
+              <div v-if="topologyNodes.length > 1" class="topology-connector"><span>主库复制链路</span></div>
+              <div class="topology" :class="`nodes-${topologyNodes.length}`">
+                <div v-for="(node, index) in topologyNodes" :key="node.name" class="node-card" :class="{ primary: index === 0, replica: index > 0 }">
                 <div class="node-head">
                   <span class="node-icon">{{ activeService.icon }}</span>
                   <strong>{{ node.name }}</strong>
@@ -346,6 +352,7 @@
                   <span>{{ node.role }}</span>
                   <span>{{ storageLabel }} 配额</span>
                 </div>
+                </div>
               </div>
             </div>
 
@@ -423,6 +430,13 @@
                 <span class="tag" :class="connectionReady ? 'tag-green' : 'tag-amber'">{{ connectionReady ? '可连接' : '等待地址' }}</span>
               </div>
               <div class="endpoint-value">{{ resultAddress }}</div>
+              <div v-if="replicaEndpoints.length" class="replica-endpoints">
+                <span class="eyebrow">REPLICA ENDPOINTS</span>
+                <div v-for="endpoint in replicaEndpoints" :key="endpoint" class="replica-endpoint">
+                  <span>从节点</span><code>{{ endpoint }}</code>
+                  <el-button text :icon="CopyDocument" aria-label="复制从节点连接地址" title="复制从节点连接地址" @click="copyText(endpoint, '从节点地址已复制')" />
+                </div>
+              </div>
               <p class="access-note">{{ isPostgreSQL ? '使用 AWX 托管的 postgres 管理员凭据连接。' : '使用交付时设置的 root 管理员账号连接。' }}</p>
               <div class="command-block">
                 <code>{{ databaseCommand }}</code>
@@ -534,7 +548,7 @@ import { computed, onBeforeUnmount, onMounted, reactive, ref, watch } from 'vue'
 import { ElMessage, ElMessageBox } from 'element-plus'
 import { ArrowDown, Back, CircleCheck, Connection, CopyDocument, DocumentCopy, Download, Monitor, Promotion, Refresh, Setting, Tickets } from '@element-plus/icons-vue'
 import { useRoute, useRouter } from 'vue-router'
-import { deliveryApi, type DeliveryMountPath, type DeliveryTarget, type DeploymentCredential, type TaskEvent } from '@/api/delivery'
+import { deliveryApi, type DeliveryMountPath, type DeliveryTarget, type DeliveryTask, type DeploymentCredential, type TaskEvent } from '@/api/delivery'
 import { useAuthStore } from '@/stores/auth'
 import { useBusinessLineStore } from '@/stores/businessLine'
 import { useBusinessLineMockProfile } from '@/utils/businessLineMock'
@@ -617,6 +631,7 @@ interface WorkbenchSnapshot {
   deploymentId: string
   deliveryError: string
   deliveredHost: string
+  deliveredHosts?: string[]
   deliveredPort?: number
   lastDeliveryStatus: string
   deliveryLog: string
@@ -660,7 +675,7 @@ const basicServices = ref<Service[]>([
     icon: 'My',
     bgColor: 'var(--logo-w-bg)',
     iconColor: 'var(--tag-blue-text)',
-    description: '单实例标准化交付，完成后自动注册进 CloudDM / open-cdm 数据源，统一审核 SQL 上线。',
+    description: '支持单实例和两节点异步主从交付，完成后自动注册进 CloudDM / open-cdm 数据源。',
     playbook: 'roles/mysql-deploy',
     version: 'v8.0',
     status: '可交付',
@@ -669,6 +684,7 @@ const basicServices = ref<Service[]>([
     versions: ['MySQL 8.0', 'MySQL 8.4'],
     modes: [
       { value: 'single', label: '单实例' },
+      { value: 'replica', label: '一主多从' },
     ],
     specs: ['1C / 2G', '2C / 4G', '4C / 8G', '8C / 16G', '16C / 32G'],
     disks: ['20 GB', '50 GB', '100 GB', '500 GB', '1000 GB'],
@@ -816,6 +832,7 @@ const canceling = ref(false)
 const deploymentId = ref('')
 const deliveryError = ref('')
 const deliveredHost = ref('')
+const deliveredHosts = ref<string[]>([])
 const deliveredPort = ref<number>()
 const deliveryTargets = ref<DeliveryTarget[]>([])
 const selectedTargetId = ref<number>()
@@ -931,10 +948,15 @@ const topologyNodes = computed(() => {
     ]
   }
   return activeServiceKey.value === 'mysql'
-    ? [
-        { name: 'db-tx-021', ip: '10.24.18.21', role: '主节点' },
-        { name: 'db-tx-022', ip: '10.24.18.22', role: '从节点' },
-      ]
+    ? Array.from({ length: deliveryForm.replicaCount + 1 }, (_, index) => {
+        const selectedName = deliveryForm.targetHosts[index]
+        const host = targetHosts.value.find((item) => item.name === selectedName) || targetHosts.value[index]
+        return {
+          name: host?.name || `等待调度 ${index + 1}`,
+          ip: host?.ip || '由 AWX Inventory 分配',
+          role: index === 0 ? '主节点' : `从节点 ${index}`,
+        }
+      })
     : [
         { name: 'ngx-tx-011', ip: '10.24.31.11', role: '主节点' },
         { name: 'ngx-tx-012', ip: '10.24.31.12', role: '备用节点' },
@@ -949,6 +971,7 @@ const runnerPreview = computed(() => {
     `component: ${activeService.value?.key || '-'}`,
     `instance: ${deliveryForm.instanceName}`,
     `topology: ${currentModeLabel.value}`,
+    ...(deliveryForm.mode === 'replica' ? [`replica_count: ${deliveryForm.replicaCount}`] : []),
     `limit: ${selectedTargetHostText.value}`,
     `${isPostgreSQL.value ? 'data_root' : 'data_disk'}: ${deliveryForm.dataDisk}`,
     `resources: ${deliveryForm.spec} / ${storageLabel.value}`,
@@ -968,13 +991,14 @@ const credentialEligible = computed(() => {
 const revealedRootCredential = computed(() => revealedCredentials.value.find((item) => item.username === 'root'))
 const resultReady = computed(() => !taskStateLoading.value && !running.value && isTerminalDeliveryStatus(lastDeliveryStatus.value))
 const selectedTargetHostText = computed(() => {
-  if (isPostgreSQL.value && deliveryForm.mode === 'primary_replica') {
+  if ((isPostgreSQL.value && deliveryForm.mode === 'primary_replica') || (activeServiceKey.value === 'mysql' && deliveryForm.mode === 'replica')) {
     return deliveryForm.targetHosts.length ? deliveryForm.targetHosts.join(', ') : '由 AWX Inventory 分配'
   }
   return deliveryForm.targetHost || '由 AWX Inventory 分配'
 })
 const previewAddress = computed(() => `${selectedHost.value?.ip || 'AWX 自动分配'}:${deliveryForm.port || '自动端口'}`)
 const resultAddress = computed(() => connectionReady.value ? `${deliveredHost.value}:${deliveredPort.value}` : '交付接口未返回地址')
+const replicaEndpoints = computed(() => deliveredHosts.value.slice(1).map((host) => `${host}:${deliveredPort.value || ''}`.replace(/:$/, '')))
 const connectionUri = computed(() => {
   if (!connectionReady.value) return ''
   return isPostgreSQL.value ? `postgresql://postgres@${deliveredHost.value}:${deliveredPort.value}/postgres` : `mysql://root@${deliveredHost.value}:${deliveredPort.value}`
@@ -1134,6 +1158,7 @@ function persistWorkbench() {
     deploymentId: deploymentId.value,
     deliveryError: deliveryError.value,
     deliveredHost: deliveredHost.value,
+    deliveredHosts: deliveredHosts.value,
     deliveredPort: deliveredPort.value,
     lastDeliveryStatus: lastDeliveryStatus.value,
     deliveryLog: deliveryLog.value,
@@ -1197,6 +1222,7 @@ async function restoreWorkbench() {
   deploymentId.value = snapshot.deploymentId
   deliveryError.value = snapshot.deliveryError
   deliveredHost.value = snapshot.deliveredHost
+  deliveredHosts.value = snapshot.deliveredHosts?.length ? snapshot.deliveredHosts : (snapshot.deliveredHost ? [snapshot.deliveredHost] : [])
   deliveredPort.value = snapshot.deliveredPort
   lastDeliveryStatus.value = snapshot.lastDeliveryStatus
   deliveryLog.value = snapshot.deliveryLog
@@ -1209,7 +1235,7 @@ async function restoreWorkbench() {
     taskStateLoading.value = true
     try {
       const data = await deliveryApi.getTask(snapshot.deploymentId)
-      deliveredHost.value = data.task.target_host_ip || deliveredHost.value
+      updateDeliveredHosts(data.task)
       deliveredPort.value = (isPostgreSQL.value ? data.task.postgresql_port : data.task.mysql_port) || deliveredPort.value
       lastDeliveryStatus.value = data.task.status
       credentialAvailable.value = isPostgreSQL.value ? false : data.task.credential_available
@@ -1304,6 +1330,7 @@ function resetExecutionState() {
   canceling.value = false
   deploymentId.value = ''
   deliveredHost.value = ''
+  deliveredHosts.value = []
   deliveredPort.value = undefined
   deliveryLog.value = '[ready] 等待创建交付任务...'
   seenEventIds.value = new Set()
@@ -1352,6 +1379,24 @@ async function precheck() {
     ElMessage.warning('当前没有可用的 AWX 部署模板，请联系平台管理员配置')
     return
   }
+  if (activeServiceKey.value === 'mysql' && deliveryForm.mode === 'replica' && targetHosts.value.length < 2) {
+    precheckPassed.value = false
+    ElMessage.error('一主一从至少需要两个可用的 AWX Inventory 主机')
+    return
+  }
+  if (activeServiceKey.value === 'mysql' && deliveryForm.mode === 'replica') {
+    const requiredHosts = deliveryForm.replicaCount + 1
+    if (targetHosts.value.length < requiredHosts) {
+      precheckPassed.value = false
+      ElMessage.warning(`一主 ${deliveryForm.replicaCount} 从需要 ${requiredHosts} 台不同主机，当前 Inventory 只有 ${targetHosts.value.length} 台`)
+      return
+    }
+    if (deliveryForm.targetHosts.length > 0 && deliveryForm.targetHosts.length !== requiredHosts) {
+      precheckPassed.value = false
+      ElMessage.warning(`请按主节点、从节点顺序选择 ${requiredHosts} 台主机，或清空后由平台自动分配`)
+      return
+    }
+  }
   if (!isPostgreSQL.value && deliveryForm.port !== undefined && (deliveryForm.port < 13306 || deliveryForm.port > 13999)) {
     ElMessage.warning('手动端口必须在 13306–13999 范围内')
     return
@@ -1488,10 +1533,12 @@ function mysqlDeliveryPayload(businessLineId: number) {
     namespace: normalizeDNSLabel(currentName.value),
     instance_name: normalizeDNSLabel(deliveryForm.instanceName),
     mysql_version: mysqlVersionValue(deliveryForm.version),
-    topology: 'standalone',
+    topology: deliveryForm.mode === 'replica' ? 'primary_replica' : 'standalone',
+    replica_count: deliveryForm.mode === 'replica' ? deliveryForm.replicaCount : 0,
     mysql_port: deliveryForm.port || 0,
     data_disk: deliveryForm.dataDisk,
     target_host: deliveryForm.targetHost || undefined,
+    target_hosts: deliveryForm.mode === 'replica' && deliveryForm.targetHosts.length ? deliveryForm.targetHosts : undefined,
     cpu_milli: resources.cpuMilli,
     memory_mi: resources.memoryMi,
     storage_gi: deliveryForm.storageGi,
@@ -1549,6 +1596,12 @@ function hostLabel(host: TargetHostOption) {
   return host.ip ? `${host.name} · ${host.ip}` : host.name
 }
 
+function updateDeliveredHosts(task: DeliveryTask) {
+  const hosts = (task.target_host_ips || '').split(',').map((host) => host.trim()).filter(Boolean)
+  deliveredHosts.value = hosts.length ? hosts : (task.target_host_ip ? [task.target_host_ip] : deliveredHosts.value)
+  deliveredHost.value = task.target_host_ip || deliveredHost.value || deliveredHosts.value[0] || ''
+}
+
 function startTaskPolling(id: string, resetEvents = false) {
   stopPolling()
   if (resetEvents) seenEventIds.value = new Set()
@@ -1564,7 +1617,7 @@ function stopPolling() {
 async function pollTask(id: string) {
   try {
     const data = await deliveryApi.getTask(id)
-    deliveredHost.value = data.task.target_host_ip || deliveredHost.value
+    updateDeliveredHosts(data.task)
     deliveredPort.value = (isPostgreSQL.value ? data.task.postgresql_port : data.task.mysql_port) || deliveredPort.value
     credentialAvailable.value = isPostgreSQL.value ? false : data.task.credential_available
     upsertDeliveryHistory(id, data.task.status, data.task.error_message || '', data.task.created_at)
@@ -2346,6 +2399,13 @@ h4 {
 .preview-panel {
   position: sticky;
   top: 16px;
+  min-width: 0;
+}
+
+.preview-panel > .section-head {
+  margin-bottom: 10px;
+  padding-bottom: 12px;
+  border-bottom: 1px solid var(--line-soft);
 }
 
 .section-head,
@@ -2720,14 +2780,22 @@ h4 {
 .preview-facts {
   display: grid;
   grid-template-columns: repeat(3, minmax(0, 1fr));
-  gap: 10px;
+  gap: 0;
   margin-bottom: 12px;
-  padding-bottom: 12px;
+  padding: 10px 0;
   border-bottom: 1px solid var(--line-soft);
 }
 
 .preview-facts div {
   min-width: 0;
+  min-height: 42px;
+  padding: 0 12px;
+  border-left: 1px solid var(--line-soft);
+}
+
+.preview-facts div:first-child {
+  padding-left: 0;
+  border-left: 0;
 }
 
 .preview-facts span,
@@ -2742,12 +2810,11 @@ h4 {
 }
 
 .preview-facts strong {
-  overflow: hidden;
   color: var(--text-mid);
   font-family: var(--mono);
   font-size: 11px;
-  text-overflow: ellipsis;
-  white-space: nowrap;
+  line-height: 1.4;
+  overflow-wrap: anywhere;
 }
 
 .config-list {
@@ -2798,7 +2865,63 @@ h4 {
 .topology {
   display: grid;
   gap: 10px;
+  max-height: 300px;
+  margin: 0;
+  overflow-y: auto;
+  padding-right: 4px;
+  align-content: start;
+  scrollbar-gutter: stable;
+}
+
+.topology::-webkit-scrollbar {
+  width: 6px;
+}
+
+.topology::-webkit-scrollbar-thumb {
+  border-radius: 3px;
+  background: var(--line);
+}
+
+.topology-shell {
+  position: relative;
   margin-bottom: 14px;
+  padding: 12px;
+  border: 1px solid var(--line);
+  border-radius: 8px;
+  background: var(--bg-panel-2);
+}
+
+.topology-title {
+  display: flex;
+  align-items: baseline;
+  justify-content: space-between;
+  gap: 12px;
+  margin-bottom: 8px;
+  color: var(--text-strong);
+}
+
+.topology-title span {
+  color: var(--text-dim);
+  font-size: 12px;
+}
+
+.topology-connector {
+  position: relative;
+  height: 1px;
+  margin: 0 12px 10px;
+  border-top: 1px dashed var(--accent);
+  opacity: 0.65;
+}
+
+.topology-connector span {
+  position: absolute;
+  top: -9px;
+  left: 50%;
+  padding: 0 8px;
+  transform: translateX(-50%);
+  background: var(--bg-panel-2);
+  color: var(--accent);
+  font-size: 11px;
 }
 
 .topology.nodes-1 {
@@ -2813,19 +2936,44 @@ h4 {
   grid-template-columns: repeat(3, minmax(0, 1fr));
 }
 
+.topology.nodes-4,
+.topology.nodes-5,
+.topology.nodes-6,
+.topology.nodes-7,
+.topology.nodes-8 {
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+}
+
 .node-card {
   min-width: 0;
-  padding: 12px;
+  min-height: 112px;
+  padding: 10px 11px;
   border: 1px solid var(--line);
   border-radius: 8px;
   background: var(--bg-panel-2);
 }
 
+.node-card.primary {
+  border-color: color-mix(in srgb, var(--accent) 55%, var(--line));
+  background: color-mix(in srgb, var(--accent) 8%, var(--bg-panel-2));
+}
+
+.node-card.replica {
+  border-color: color-mix(in srgb, var(--text-dim) 45%, var(--line));
+}
+
 .node-head {
   display: flex;
   align-items: center;
   gap: 8px;
-  margin-bottom: 8px;
+  margin-bottom: 9px;
+}
+
+.node-head strong {
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
 }
 
 .node-icon {
@@ -2843,6 +2991,7 @@ h4 {
   color: var(--text-dim);
   font-family: var(--mono);
   font-size: 11px;
+  line-height: 1.35;
 }
 
 .yaml-preview,
@@ -2859,7 +3008,8 @@ h4 {
 }
 
 .yaml-preview {
-  min-height: 180px;
+  min-height: 0;
+  max-height: 260px;
   margin: 0 0 12px;
   padding: 12px 14px;
 }
@@ -2871,6 +3021,9 @@ h4 {
 }
 
 .form-actions {
+  margin-top: 12px;
+  padding-top: 12px;
+  border-top: 1px solid var(--line-soft);
   justify-content: flex-end;
   gap: 8px;
 }
diff --git a/server/go.mod b/server/go.mod
index b9d969e..2ba9677 100644
--- a/server/go.mod
+++ b/server/go.mod
@@ -5,6 +5,7 @@ go 1.26
 require (
 	github.com/gin-gonic/gin v1.11.0
 	github.com/golang-jwt/jwt/v5 v5.3.0
+	github.com/go-sql-driver/mysql v1.8.1
 	github.com/swaggo/files v1.0.1
 	github.com/swaggo/gin-swagger v1.6.1
 	github.com/swaggo/swag v1.16.3
@@ -30,7 +31,6 @@ require (
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.27.0 // indirect
-	github.com/go-sql-driver/mysql v1.8.1 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/goccy/go-yaml v1.18.0 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
diff --git a/server/internal/handler/task_log.go b/server/internal/handler/task_log.go
index 5857053..ec122d3 100644
--- a/server/internal/handler/task_log.go
+++ b/server/internal/handler/task_log.go
@@ -216,11 +216,18 @@ func (h *TaskLogHandler) getWayneTask(c *gin.Context, id string, userID uint64,
 }
 
 func awxTaskSummary(task model.DeliveryTask) taskLogSummary {
+	serviceName := "mysql"
+	serviceLabel := "MySQL"
+	if strings.EqualFold(strings.TrimSpace(task.ServiceType), "postgresql") ||
+		(strings.TrimSpace(task.ServiceType) == "" && strings.EqualFold(strings.TrimSpace(task.Component), "postgresql")) {
+		serviceName = "postgresql"
+		serviceLabel = "PostgreSQL"
+	}
 	return taskLogSummary{
 		ID:             "awx:" + task.ID,
 		Source:         "awx",
-		Service:        "mysql",
-		Name:           "MySQL 标准化交付 · " + task.InstanceName,
+		Service:        serviceName,
+		Name:           serviceLabel + " 标准化交付 · " + task.InstanceName,
 		Runner:         "AWX Job Template #" + strconv.FormatUint(task.TargetID, 10),
 		Status:         task.Status,
 		StatusText:     textForTaskStatus(task.Status),
diff --git a/server/internal/handler/task_log_test.go b/server/internal/handler/task_log_test.go
index 2417413..9fdf349 100644
--- a/server/internal/handler/task_log_test.go
+++ b/server/internal/handler/task_log_test.go
@@ -439,6 +439,33 @@ func TestAwxTaskSummary(t *testing.T) {
 	}
 }
 
+func TestAwxTaskSummaryPostgreSQL(t *testing.T) {
+	tests := []struct {
+		name        string
+		serviceType string
+		component   string
+	}{
+		{name: "service type", serviceType: "postgresql", component: "postgresql"},
+		{name: "legacy component fallback", component: "postgresql"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			summary := awxTaskSummary(model.DeliveryTask{
+				ID:           "task-postgresql",
+				ServiceType:  tt.serviceType,
+				Component:    tt.component,
+				InstanceName: "postgresql-xinfra-n1aw28",
+			})
+			if summary.Service != "postgresql" {
+				t.Fatalf("awxTaskSummary Service = %q, want %q", summary.Service, "postgresql")
+			}
+			if summary.Name != "PostgreSQL 标准化交付 · postgresql-xinfra-n1aw28" {
+				t.Fatalf("awxTaskSummary Name = %q, want PostgreSQL delivery name", summary.Name)
+			}
+		})
+	}
+}
+
 func TestWayneTaskSummary(t *testing.T) {
 	now := time.Now()
 	history := service.WayneDeploymentHistory{
diff --git a/server/internal/model/delivery.go b/server/internal/model/delivery.go
index 0565dcb..6dac9b3 100644
--- a/server/internal/model/delivery.go
+++ b/server/internal/model/delivery.go
@@ -34,17 +34,20 @@ type ResourceQuota struct {
 }
 
 type DeliveryTask struct {
-	ID                  string     `gorm:"size:36;primaryKey" json:"id"`
-	BusinessLineID      uint64     `gorm:"not null;index" json:"business_line_id"`
-	RequestedBy         uint64     `gorm:"not null;index" json:"requested_by"`
-	Component           string     `gorm:"size:32;not null;default:mysql;index" json:"component"`
-	TargetType          string     `gorm:"size:32;not null" json:"target_type"`
-	ServiceType         string     `gorm:"size:32;not null;default:'mysql';index" json:"service_type"`
-	TargetID            uint64     `gorm:"not null;index" json:"target_id"`
-	Namespace           string     `gorm:"size:63;not null;index" json:"namespace"`
-	InstanceName        string     `gorm:"size:63;not null" json:"instance_name"`
-	TargetHost          string     `gorm:"size:1024" json:"target_host,omitempty"`
-	TargetHostIP        string     `gorm:"size:64" json:"target_host_ip,omitempty"`
+	ID             string `gorm:"size:36;primaryKey" json:"id"`
+	BusinessLineID uint64 `gorm:"not null;index" json:"business_line_id"`
+	RequestedBy    uint64 `gorm:"not null;index" json:"requested_by"`
+	Component      string `gorm:"size:32;not null;default:mysql;index" json:"component"`
+	TargetType     string `gorm:"size:32;not null" json:"target_type"`
+	ServiceType    string `gorm:"size:32;not null;default:'mysql';index" json:"service_type"`
+	TargetID       uint64 `gorm:"not null;index" json:"target_id"`
+	Namespace      string `gorm:"size:63;not null;index" json:"namespace"`
+	InstanceName   string `gorm:"size:63;not null" json:"instance_name"`
+	TargetHost     string `gorm:"size:1024" json:"target_host,omitempty"`
+	TargetHostIP   string `gorm:"size:64" json:"target_host_ip,omitempty"`
+	// For primary_replica, these contain the complete node lists in primary,replica order.
+	TargetHosts         string     `gorm:"type:text" json:"target_hosts,omitempty"`
+	TargetHostIPs       string     `gorm:"type:text" json:"target_host_ips,omitempty"`
 	MySQLPort           int        `gorm:"column:mysql_port;not null;default:3307" json:"mysql_port"`
 	PostgreSQLPort      int        `gorm:"column:postgresql_port;not null;default:15432" json:"postgresql_port,omitempty"`
 	Status              string     `gorm:"size:32;not null;index" json:"status"`
@@ -101,6 +104,8 @@ type DeploymentResult struct {
 	TargetID       uint64    `gorm:"not null;index" json:"target_id"`
 	NodeName       string    `gorm:"size:128;not null;default:''" json:"node_name"`
 	Host           string    `gorm:"size:255;not null;default:''" json:"host"`
+	TargetHosts    string    `gorm:"type:text" json:"target_hosts,omitempty"`
+	TargetHostIPs  string    `gorm:"type:text" json:"target_host_ips,omitempty"`
 	Port           int       `gorm:"not null;default:0" json:"port"`
 	Version        string    `gorm:"size:64;not null;default:''" json:"version"`
 	Status         string    `gorm:"size:32;not null;index" json:"status"`
diff --git a/server/internal/service/delivery.go b/server/internal/service/delivery.go
index 840d177..0200da6 100644
--- a/server/internal/service/delivery.go
+++ b/server/internal/service/delivery.go
@@ -7,6 +7,7 @@ import (
 	"crypto/cipher"
 	"crypto/rand"
 	"crypto/sha256"
+	"database/sql"
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
@@ -24,6 +25,7 @@ import (
 
 	"github.com/1024XEngineer/xinfra/server/internal/config"
 	"github.com/1024XEngineer/xinfra/server/internal/model"
+	mysqlDriver "github.com/go-sql-driver/mysql"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 )
@@ -41,16 +43,18 @@ type MySQLDeliveryInput struct {
 	InstanceDesc   string `json:"instance_desc,omitempty"`
 	MySQLVersion   string `json:"mysql_version"`
 	Topology       string `json:"topology"`
+	ReplicaCount   int    `json:"replica_count"`
 	MySQLPort      int    `json:"mysql_port"`
 	DataDisk       string `json:"data_disk"`
 	// 调度控制（选填）：点名候选池内主机跳过自动选机，端口/配额/实机守卫照常执行
-	TargetHost string `json:"target_host"`
-	CPUMilli   int64  `json:"cpu_milli" binding:"required"`
-	MemoryMi   int64  `json:"memory_mi" binding:"required"`
-	StorageGi  int64  `json:"storage_gi" binding:"required"`
-	CPUCores   int64  `json:"cpu_cores,omitempty"`
-	MemoryGB   int64  `json:"memory_gb,omitempty"`
-	StorageGB  int64  `json:"storage_gb,omitempty"`
+	TargetHost  string   `json:"target_host"`
+	TargetHosts []string `json:"target_hosts"`
+	CPUMilli    int64    `json:"cpu_milli" binding:"required"`
+	MemoryMi    int64    `json:"memory_mi" binding:"required"`
+	StorageGi   int64    `json:"storage_gi" binding:"required"`
+	CPUCores    int64    `json:"cpu_cores,omitempty"`
+	MemoryGB    int64    `json:"memory_gb,omitempty"`
+	StorageGB   int64    `json:"storage_gb,omitempty"`
 	// 数据库配置（选填，缺省由 playbook 基线兜底）
 	Timezone            string `json:"timezone"`
 	LowerCaseTableNames *int   `json:"lower_case_table_names"`
@@ -228,6 +232,8 @@ func stringValue(value any) string {
 	switch v := value.(type) {
 	case string:
 		return v
+	case []byte:
+		return string(v)
 	case fmt.Stringer:
 		return v.String()
 	default:
@@ -329,6 +335,69 @@ func hostTaskCount(occupied []string, name string) int {
 	return count
 }
 
+// resolvePinnedPrimaryReplicaNodes 按用户显式指定的有序 target_hosts 解析 primary_replica 节点列表，
+// 首节点为主节点。返回值：节点列表、参数校验失败原因（终态）、延后调度错误（defer: 前缀，可重试）。
+func resolvePinnedPrimaryReplicaNodes(hosts []targetHost, requested []string, occupied []string, limit int, nodeCount int64, pinnedPrimary string) ([]*targetHost, string, error) {
+	if int64(len(requested)) != nodeCount {
+		return nil, fmt.Sprintf("primary_replica requires %d target_hosts, got %d", nodeCount, len(requested)), nil
+	}
+	nodes := make([]*targetHost, 0, len(requested))
+	seen := map[string]struct{}{}
+	for index, requestedHost := range requested {
+		var selected *targetHost
+		for i := range hosts {
+			if hosts[i].Name == requestedHost {
+				selected = &hosts[i]
+				break
+			}
+		}
+		if selected == nil {
+			return nil, fmt.Sprintf("target_hosts[%d] %q is not in the candidate host pool", index, requestedHost), nil
+		}
+		if _, exists := seen[selected.Name]; exists {
+			return nil, fmt.Sprintf("target_hosts contains duplicate host %q", selected.Name), nil
+		}
+		if hostTaskCount(occupied, selected.Name) >= max(limit, 1) {
+			return nil, "", fmt.Errorf("defer: pinned host %s reached the per-host instance limit %d", selected.Name, max(limit, 1))
+		}
+		seen[selected.Name] = struct{}{}
+		nodes = append(nodes, selected)
+	}
+	if pinnedPrimary != "" && nodes[0].Name != pinnedPrimary {
+		return nil, "target_host must match the first primary_replica target_hosts entry", nil
+	}
+	return nodes, "", nil
+}
+
+func topologyNodeCount(input MySQLDeliveryInput) int64 {
+	if input.Topology == "primary_replica" {
+		replicas := input.ReplicaCount
+		if replicas < 1 {
+			replicas = 1
+		}
+		return int64(replicas + 1)
+	}
+	return 1
+}
+
+func splitHosts(raw string) []string {
+	parts := strings.Split(raw, ",")
+	out := make([]string, 0, len(parts))
+	seen := map[string]struct{}{}
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if part == "" {
+			continue
+		}
+		if _, ok := seen[part]; ok {
+			continue
+		}
+		seen[part] = struct{}{}
+		out = append(out, part)
+	}
+	return out
+}
+
 // 端口池 13306-13999：混合分配模型，用户留空时自动分配，可覆盖为池内指定端口。
 const (
 	mysqlPortPoolStart = 13306
@@ -781,9 +850,8 @@ func ensureInstanceNameAvailable(tx *gorm.DB, businessLineID uint64, component,
 // 8.0 走 Ubuntu 自带源，8.4 走 MySQL 官方 APT 源；5.6/5.7 已 EOL 且无 noble 包，不支持。
 var supportedMySQLVersions = map[string]bool{"8.0": true, "8.4": true}
 
-// 拓扑白名单：playbook 已支持 primary_replica/mgr_3 的配置渲染，
-// 但调度器仍是单主机模型且复制编排未自动化，本期仅放开 standalone。
-var supportedTopologies = map[string]bool{"standalone": true}
+// 拓扑白名单：支持 standalone 和一主多从 primary_replica；MGR 暂未开放。
+var supportedTopologies = map[string]bool{"standalone": true, "primary_replica": true}
 
 const rollbackLaunchTimeout = 2 * time.Minute
 
@@ -823,7 +891,10 @@ func validateDeliveryInput(input MySQLDeliveryInput, _ []string) error {
 		return fmt.Errorf("unsupported mysql_version %q, supported: 8.0, 8.4 (5.6/5.7 are EOL and have no Ubuntu 24.04 packages)", input.MySQLVersion)
 	}
 	if input.Topology != "" && !supportedTopologies[input.Topology] {
-		return fmt.Errorf("unsupported topology %q, supported: standalone (primary_replica/mgr_3 pending scheduler support)", input.Topology)
+		return fmt.Errorf("unsupported topology %q, supported: standalone, primary_replica", input.Topology)
+	}
+	if input.Topology == "primary_replica" && (input.ReplicaCount < 1 || input.ReplicaCount > 7) {
+		return fmt.Errorf("replica_count must be between 1 and 7 for primary_replica")
 	}
 	if input.MySQLPort != 0 && (input.MySQLPort < mysqlPortPoolStart || input.MySQLPort > mysqlPortPoolEnd) {
 		return fmt.Errorf("mysql_port must be left empty for auto allocation or within the pool %d-%d", mysqlPortPoolStart, mysqlPortPoolEnd)
@@ -831,6 +902,20 @@ func validateDeliveryInput(input MySQLDeliveryInput, _ []string) error {
 	if input.TargetHost != "" && (len(input.TargetHost) > 253 || !hostNamePattern.MatchString(input.TargetHost)) {
 		return fmt.Errorf("target_host must be a valid inventory host name")
 	}
+	if len(input.TargetHosts) > 8 {
+		return fmt.Errorf("target_hosts may contain at most 8 nodes")
+	}
+	seenHosts := map[string]struct{}{}
+	for _, host := range input.TargetHosts {
+		host = strings.TrimSpace(host)
+		if len(host) > 253 || !hostNamePattern.MatchString(host) {
+			return fmt.Errorf("target_hosts contains invalid inventory host %q", host)
+		}
+		if _, exists := seenHosts[host]; exists {
+			return fmt.Errorf("target_hosts contains duplicate host %q", host)
+		}
+		seenHosts[host] = struct{}{}
+	}
 	if input.Timezone != "" && !timezonePattern.MatchString(input.Timezone) {
 		return fmt.Errorf("timezone must be an offset like +08:00, SYSTEM, or a named zone like Asia/Shanghai")
 	}
@@ -881,6 +966,9 @@ func normalizeMySQLDeliveryInput(input *MySQLDeliveryInput) {
 	input.InstanceName = normalizeDNSLabel(input.InstanceName)
 	input.InstanceDesc = strings.TrimSpace(input.InstanceDesc)
 	input.TargetHost = strings.TrimSpace(input.TargetHost)
+	for i := range input.TargetHosts {
+		input.TargetHosts[i] = strings.TrimSpace(input.TargetHosts[i])
+	}
 	input.DataDisk = strings.TrimSpace(input.DataDisk)
 	if input.MySQLVersion == "" {
 		input.MySQLVersion = "8.0"
@@ -888,6 +976,9 @@ func normalizeMySQLDeliveryInput(input *MySQLDeliveryInput) {
 	if input.Topology == "" {
 		input.Topology = "standalone"
 	}
+	if input.Topology == "primary_replica" && input.ReplicaCount == 0 {
+		input.ReplicaCount = 1
+	}
 	if input.CPUMilli == 0 && input.CPUCores != 0 {
 		input.CPUMilli = input.CPUCores * 1000
 	}
@@ -1641,7 +1732,8 @@ func (s *DeliveryService) claimAndReserve(ctx context.Context) (*model.DeliveryT
 				}
 			}
 		}
-		quotaOK, err := checkResourceQuota(tx, task.BusinessLineID, task.TargetID, payload)
+		nodeCount := topologyNodeCount(payload.MySQLDeliveryInput)
+		quotaOK, err := checkResourceQuota(tx, task.BusinessLineID, task.TargetID, payload, nodeCount)
 		if err != nil {
 			return err
 		}
@@ -1654,9 +1746,26 @@ func (s *DeliveryService) claimAndReserve(ctx context.Context) (*model.DeliveryT
 		}
 		var occupied []string
 		occupiedExclude := allocationReleasedTaskStatuses()
-		if err := tx.Model(&model.DeliveryTask{}).Where("target_id = ? AND target_host <> ? AND status NOT IN ?", task.TargetID, "", occupiedExclude).Pluck("target_host", &occupied).Error; err != nil {
+		var taskAllocations []struct{ TargetHost, TargetHosts string }
+		if err := tx.Model(&model.DeliveryTask{}).Select("target_host, target_hosts").Where("target_id = ? AND status NOT IN ?", task.TargetID, occupiedExclude).Find(&taskAllocations).Error; err != nil {
 			return err
 		}
+		for _, allocation := range taskAllocations {
+			occupied = append(occupied, splitHosts(allocation.TargetHosts)...)
+			if allocation.TargetHosts == "" {
+				occupied = append(occupied, splitHosts(allocation.TargetHost)...)
+			}
+		}
+		var resultAllocations []struct{ NodeName, TargetHosts string }
+		if err := tx.Model(&model.DeploymentResult{}).Select("node_name, target_hosts").Where("target_id = ? AND status IN ?", task.TargetID, occupiedDeploymentStatuses()).Find(&resultAllocations).Error; err != nil {
+			return err
+		}
+		for _, allocation := range resultAllocations {
+			occupied = append(occupied, splitHosts(allocation.TargetHosts)...)
+			if allocation.TargetHosts == "" {
+				occupied = append(occupied, splitHosts(allocation.NodeName)...)
+			}
+		}
 		limit := s.cfg.DeliveryHostInstanceLimit
 		var host *targetHost
 		if payload.TargetHost != "" {
@@ -1679,30 +1788,103 @@ func (s *DeliveryService) claimAndReserve(ctx context.Context) (*model.DeliveryT
 		if host == nil {
 			return fmt.Errorf("defer: no free host available on target")
 		}
+		nodes := []*targetHost{host}
+		if nodeCount > 1 {
+			if len(payload.TargetHosts) > 0 {
+				pinned, validationMsg, deferErr := resolvePinnedPrimaryReplicaNodes(meta.Hosts, payload.TargetHosts, occupied, limit, nodeCount, payload.TargetHost)
+				if deferErr != nil {
+					return deferErr
+				}
+				if validationMsg != "" {
+					return s.failInTransaction(tx, &task, model.TaskValidationFailed, validationMsg)
+				}
+				// 显式列表以首节点为主节点：覆盖此前默认挑选的空闲主机，
+				// 避免 task.TargetHost/IP 与台账、凭据指向未部署节点。
+				nodes = pinned
+				host = nodes[0]
+			} else {
+				for i := range meta.Hosts {
+					candidate := &meta.Hosts[i]
+					if candidate.Name == host.Name || hostTaskCount(occupied, candidate.Name) >= max(limit, 1) {
+						continue
+					}
+					nodes = append(nodes, candidate)
+					if int64(len(nodes)) == nodeCount {
+						break
+					}
+				}
+				if int64(len(nodes)) != nodeCount {
+					return fmt.Errorf("defer: only %d free hosts available for primary_replica requiring %d", len(nodes), nodeCount)
+				}
+			}
+		}
 		// 端口池混合分配：同主机已占端口 = 非终态任务分配端口 ∪ 存量 active 实例端口。
 		var usedPorts []int
-		if err := tx.Model(&model.DeliveryTask{}).Where("target_host = ? AND status NOT IN ?", host.Name, occupiedExclude).Pluck("mysql_port", &usedPorts).Error; err != nil {
+		var portAllocations []struct {
+			TargetHost, TargetHosts string
+			MySQLPort               int
+		}
+		if err := tx.Model(&model.DeliveryTask{}).Select("target_host, target_hosts, mysql_port").Where("target_id = ? AND status NOT IN ?", task.TargetID, occupiedExclude).Find(&portAllocations).Error; err != nil {
 			return err
 		}
 		var instancePorts []int
-		if err := tx.Model(&model.DeploymentResult{}).
-			Where("component = ? AND service_type = ? AND node_name = ? AND status IN ?", "mysql", "database", host.Name, occupiedDeploymentStatuses()).
-			Pluck("port", &instancePorts).Error; err != nil {
+		var resultPorts []struct {
+			NodeName, TargetHosts string
+			Port                  int
+		}
+		if err := tx.Model(&model.DeploymentResult{}).Select("node_name, target_hosts, port").Where("target_id = ? AND component = ? AND service_type = ? AND status IN ?", task.TargetID, "mysql", "database", occupiedDeploymentStatuses()).Find(&resultPorts).Error; err != nil {
 			return err
 		}
+		for _, allocation := range portAllocations {
+			for _, allocatedHost := range splitHosts(allocation.TargetHosts) {
+				for _, node := range nodes {
+					if allocatedHost == node.Name {
+						usedPorts = append(usedPorts, allocation.MySQLPort)
+					}
+				}
+			}
+			if allocation.TargetHosts == "" && allocation.TargetHost != "" {
+				for _, node := range nodes {
+					if allocation.TargetHost == node.Name {
+						usedPorts = append(usedPorts, allocation.MySQLPort)
+					}
+				}
+			}
+		}
+		for _, allocation := range resultPorts {
+			hosts := splitHosts(allocation.TargetHosts)
+			if len(hosts) == 0 {
+				hosts = splitHosts(allocation.NodeName)
+			}
+			for _, allocatedHost := range hosts {
+				for _, node := range nodes {
+					if allocatedHost == node.Name {
+						instancePorts = append(instancePorts, allocation.Port)
+					}
+				}
+			}
+		}
 		port, portErr := allocatePort(payload.MySQLPort, append(usedPorts, instancePorts...))
 		if portErr != nil {
 			return s.failInTransaction(tx, &task, model.TaskValidationFailed, portErr.Error())
 		}
-		reservation := model.ResourceReservation{TaskID: task.ID, BusinessLineID: task.BusinessLineID, TargetID: task.TargetID, CPUMilli: payload.CPUMilli, MemoryMi: payload.MemoryMi, StorageGi: payload.StorageGi, InstanceCount: 1, Status: "reserved", ExpiresAt: time.Now().Add(time.Duration(s.cfg.ReservationTTLMinutes) * time.Minute)}
+		primaryHostNames := make([]string, 0, len(nodes))
+		primaryHostIPs := make([]string, 0, len(nodes))
+		for _, node := range nodes {
+			primaryHostNames = append(primaryHostNames, node.Name)
+			primaryHostIPs = append(primaryHostIPs, node.IP)
+		}
+		reservation := model.ResourceReservation{TaskID: task.ID, BusinessLineID: task.BusinessLineID, TargetID: task.TargetID, CPUMilli: payload.CPUMilli * nodeCount, MemoryMi: payload.MemoryMi * nodeCount, StorageGi: payload.StorageGi * nodeCount, InstanceCount: nodeCount, Status: "reserved", ExpiresAt: time.Now().Add(time.Duration(s.cfg.ReservationTTLMinutes) * time.Minute)}
 		if err := tx.Create(&reservation).Error; err != nil {
 			return err
 		}
-		if err := tx.Model(&model.DeliveryTask{}).Where("id = ?", task.ID).Updates(map[string]any{"target_host": host.Name, "target_host_ip": host.IP, "mysql_port": port}).Error; err != nil {
+		if err := tx.Model(&model.DeliveryTask{}).Where("id = ?", task.ID).Updates(map[string]any{"target_host": host.Name, "target_host_ip": host.IP, "target_hosts": strings.Join(primaryHostNames, ","), "target_host_ips": strings.Join(primaryHostIPs, ","), "mysql_port": port}).Error; err != nil {
 			return err
 		}
 		task.TargetHost = host.Name
 		task.TargetHostIP = host.IP
+		task.TargetHosts = strings.Join(primaryHostNames, ",")
+		task.TargetHostIPs = strings.Join(primaryHostIPs, ",")
 		task.MySQLPort = port
 		if err := s.transitionTx(tx, &task, model.TaskDispatching, "resources reserved", ""); err != nil {
 			return err
@@ -1716,7 +1898,7 @@ func (s *DeliveryService) claimAndReserve(ctx context.Context) (*model.DeliveryT
 	return &task, err
 }
 
-func checkResourceQuota(tx *gorm.DB, businessLineID, targetID uint64, payload deliveryPayload) (bool, error) {
+func checkResourceQuota(tx *gorm.DB, businessLineID, targetID uint64, payload deliveryPayload, nodeCount int64) (bool, error) {
 	var quota model.ResourceQuota
 	if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).Where("business_line_id = ? AND target_id = ?", businessLineID, targetID).First(&quota).Error; err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
@@ -1732,10 +1914,10 @@ func checkResourceQuota(tx *gorm.DB, businessLineID, targetID uint64, payload de
 	if err := tx.Model(&model.ResourceReservation{}).Select("COALESCE(SUM(cpu_milli),0) cpu, COALESCE(SUM(memory_mi),0) memory, COALESCE(SUM(storage_gi),0) storage, COALESCE(SUM(instance_count),0) instances").Where("business_line_id = ? AND target_id = ? AND (status = ? OR (status = ? AND expires_at > ?))", businessLineID, targetID, "rollback", "reserved", time.Now()).Scan(&reserved).Error; err != nil {
 		return false, err
 	}
-	return used.CPU+reserved.CPU+payload.CPUMilli <= quota.CPUMilli &&
-		used.Memory+reserved.Memory+payload.MemoryMi <= quota.MemoryMi &&
-		used.Storage+reserved.Storage+payload.StorageGi <= quota.StorageGi &&
-		used.Instances+reserved.Instances+1 <= quota.InstanceLimit, nil
+	return used.CPU+reserved.CPU+payload.CPUMilli*nodeCount <= quota.CPUMilli &&
+		used.Memory+reserved.Memory+payload.MemoryMi*nodeCount <= quota.MemoryMi &&
+		used.Storage+reserved.Storage+payload.StorageGi*nodeCount <= quota.StorageGi &&
+		used.Instances+reserved.Instances+nodeCount <= quota.InstanceLimit, nil
 }
 
 func (s *DeliveryService) failInTransaction(tx *gorm.DB, task *model.DeliveryTask, status, message string) error {
@@ -1846,9 +2028,12 @@ func mysqlDeploymentMetadata(task model.DeliveryTask, payload deliveryPayload) m
 		"instance_name":                  instance,
 		"target_host":                    task.TargetHost,
 		"target_host_ip":                 task.TargetHostIP,
+		"target_hosts":                   task.TargetHosts,
+		"target_host_ips":                task.TargetHostIPs,
 		"mysql_port":                     task.MySQLPort,
 		"mysql_version":                  mysqlVersion,
 		"topology":                       topology,
+		"replica_count":                  payload.ReplicaCount,
 		"cpu_milli":                      payload.CPUMilli,
 		"memory_mi":                      payload.MemoryMi,
 		"storage_gi":                     payload.StorageGi,
@@ -1911,6 +2096,73 @@ func mysqlReady(ctx context.Context, address string) error {
 	return conn.Close()
 }
 
+// mysqlReplicationReady verifies the runtime replication state instead of
+// treating an open TCP port as evidence that a replica is configured. The
+// delivery credential is already encrypted at rest and is only decrypted for
+// this short-lived health check.
+func mysqlReplicationReady(ctx context.Context, address, username, password string) error {
+	config := mysqlDriver.Config{
+		User:                 username,
+		Passwd:               password,
+		Net:                  "tcp",
+		Addr:                 address,
+		Timeout:              5 * time.Second,
+		ReadTimeout:          5 * time.Second,
+		WriteTimeout:         5 * time.Second,
+		AllowNativePasswords: true,
+	}
+	db, err := sql.Open("mysql", config.FormatDSN())
+	if err != nil {
+		return err
+	}
+	defer db.Close()
+
+	if err := db.PingContext(ctx); err != nil {
+		return fmt.Errorf("connect: %w", err)
+	}
+	rows, err := db.QueryContext(ctx, "SHOW REPLICA STATUS")
+	if err != nil {
+		return fmt.Errorf("query replica status: %w", err)
+	}
+	defer rows.Close()
+	columns, err := rows.Columns()
+	if err != nil {
+		return err
+	}
+	if !rows.Next() {
+		if err := rows.Err(); err != nil {
+			return err
+		}
+		return errors.New("replica status is empty; CHANGE REPLICATION SOURCE TO was not applied")
+	}
+	values := make([]any, len(columns))
+	refs := make([]any, len(columns))
+	for i := range values {
+		refs[i] = &values[i]
+	}
+	if err := rows.Scan(refs...); err != nil {
+		return err
+	}
+	status := make(map[string]string, len(columns))
+	for i, column := range columns {
+		status[column] = strings.TrimSpace(stringValue(values[i]))
+	}
+	ioRunning := status["Replica_IO_Running"]
+	if ioRunning == "" {
+		ioRunning = status["Slave_IO_Running"]
+	}
+	sqlRunning := status["Replica_SQL_Running"]
+	if sqlRunning == "" {
+		sqlRunning = status["Slave_SQL_Running"]
+	}
+	if ioRunning != "Yes" || sqlRunning != "Yes" {
+		lastIOError := status["Last_IO_Error"]
+		lastSQLError := status["Last_SQL_Error"]
+		return fmt.Errorf("replication threads are not healthy (io=%q sql=%q io_error=%q sql_error=%q)", ioRunning, sqlRunning, lastIOError, lastSQLError)
+	}
+	return nil
+}
+
 func (s *DeliveryService) DispatchOnce(ctx context.Context) error {
 	task, err := s.claimAndReserve(ctx)
 	if err != nil {
@@ -1980,7 +2232,11 @@ func (s *DeliveryService) CreateExecution(ctx context.Context, taskID, payloadHa
 	}
 	extraVars["delivery_callback_url"] = s.deliveryCallbackURL(task.ID)
 	extraVars["delivery_callback_token"] = s.cfg.AWXWebhookToken
-	job, err := s.awx.Launch(ctx, target.AWXTemplateID, AWXLaunchRequest{InventoryID: target.AWXInventoryID, Limit: task.TargetHost, ExtraVars: extraVars})
+	limit := task.TargetHosts
+	if strings.TrimSpace(limit) == "" {
+		limit = task.TargetHost
+	}
+	job, err := s.awx.Launch(ctx, target.AWXTemplateID, AWXLaunchRequest{InventoryID: target.AWXInventoryID, Limit: limit, ExtraVars: extraVars})
 	if err != nil {
 		_ = s.db.WithContext(ctx).Model(&execution).Updates(map[string]any{"status": "failed", "finished_at": time.Now()})
 		return nil, false, err
@@ -2012,13 +2268,30 @@ func deliveryExtraVars(task *model.DeliveryTask, payload deliveryPayload, meta t
 		// 存量任务的 ImmutablePayload 无 topology 字段，回退到 target metadata。
 		topology = meta.Topology
 	}
+	allHosts := task.TargetHosts
+	if strings.TrimSpace(allHosts) == "" {
+		allHosts = task.TargetHost
+	}
 	vars := map[string]any{
 		"task_id": task.ID, "payload_hash": task.PayloadHash,
-		"target_hosts": task.TargetHost, "topology": topology,
+		"target_hosts": allHosts, "topology": topology,
+		"replica_count": payload.ReplicaCount,
 		"instance_name": payload.InstanceName, "mysql_port": task.MySQLPort,
 		"memory_mb": payload.MemoryMi, "storage_gb": payload.StorageGi,
 		"mysql_version": payload.MySQLVersion,
 	}
+	if topology == "primary_replica" {
+		nodes := splitHosts(allHosts)
+		if len(nodes) >= 2 {
+			vars["mysql_primary_host"] = nodes[0]
+			vars["mysql_replica_hosts"] = strings.Join(nodes[1:], ",")
+			ips := splitHosts(task.TargetHostIPs)
+			if len(ips) >= 2 {
+				vars["mysql_primary_ip"] = ips[0]
+				vars["mysql_replica_ips"] = strings.Join(ips[1:], ",")
+			}
+		}
+	}
 	if payload.DataDisk != "" {
 		vars["data_disk"] = payload.DataDisk
 	}
@@ -2348,10 +2621,36 @@ func (s *DeliveryService) completeTask(ctx context.Context, taskID string) error
 	if err := json.Unmarshal([]byte(task.ImmutablePayload), &payload); err != nil {
 		return err
 	}
-	addr := fmt.Sprintf("%s:%d", task.TargetHostIP, task.MySQLPort)
-	if err := mysqlReady(ctx, addr); err != nil {
-		return fmt.Errorf("MySQL health check failed: %w", err)
+	addresses := splitHosts(task.TargetHostIPs)
+	if len(addresses) == 0 {
+		addresses = []string{task.TargetHostIP}
 	}
+	for _, hostIP := range addresses {
+		addr := fmt.Sprintf("%s:%d", hostIP, task.MySQLPort)
+		if err := mysqlReady(ctx, addr); err != nil {
+			return fmt.Errorf("MySQL health check failed on %s: %w", addr, err)
+		}
+	}
+	if payload.Topology == "primary_replica" {
+		if len(addresses) < 2 {
+			return fmt.Errorf("primary_replica requires at least one replica address, got %d", len(addresses))
+		}
+		credentialVars, err := s.deploymentCredentialVars(ctx, task.ID)
+		if err != nil {
+			return fmt.Errorf("replication health check credential unavailable: %w", err)
+		}
+		rootPassword := credentialVars["mysql_root_password"]
+		if rootPassword == "" {
+			return errors.New("replication health check credential unavailable: root password is empty")
+		}
+		for _, hostIP := range addresses[1:] {
+			addr := fmt.Sprintf("%s:%d", hostIP, task.MySQLPort)
+			if err := mysqlReplicationReady(ctx, addr, "root", rootPassword); err != nil {
+				return fmt.Errorf("MySQL replication health check failed on %s: %w", addr, err)
+			}
+		}
+	}
+	nodeCount := topologyNodeCount(payload.MySQLDeliveryInput)
 	now := time.Now()
 	if err := s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		if err := s.transitionTx(tx, &task, model.TaskRegistering, "AWX succeeded and MySQL health check passed", ""); err != nil {
@@ -2368,6 +2667,8 @@ func (s *DeliveryService) completeTask(ctx context.Context, taskID string) error
 			TargetID:       task.TargetID,
 			NodeName:       task.TargetHost,
 			Host:           task.TargetHostIP,
+			TargetHosts:    task.TargetHosts,
+			TargetHostIPs:  task.TargetHostIPs,
 			Port:           task.MySQLPort,
 			Version:        payload.MySQLVersion,
 			Status:         "active",
@@ -2382,7 +2683,7 @@ func (s *DeliveryService) completeTask(ctx context.Context, taskID string) error
 		if err := tx.Model(&model.DeploymentCredential{}).Where("task_id = ? AND status = ?", task.ID, "pending").Updates(map[string]any{"deployment_result_id": result.ID, "status": "available"}).Error; err != nil {
 			return err
 		}
-		if err := tx.Create(&model.ResourceUsage{TaskID: task.ID, InstanceID: result.ID, BusinessLineID: task.BusinessLineID, TargetID: task.TargetID, CPUMilli: payload.CPUMilli, MemoryMi: payload.MemoryMi, StorageGi: payload.StorageGi, InstanceCount: 1, Status: "active"}).Error; err != nil {
+		if err := tx.Create(&model.ResourceUsage{TaskID: task.ID, InstanceID: result.ID, BusinessLineID: task.BusinessLineID, TargetID: task.TargetID, CPUMilli: payload.CPUMilli * nodeCount, MemoryMi: payload.MemoryMi * nodeCount, StorageGi: payload.StorageGi * nodeCount, InstanceCount: nodeCount, Status: "active"}).Error; err != nil {
 			return err
 		}
 		if err := tx.Model(&model.ResourceReservation{}).Where("task_id = ? AND status = ?", task.ID, "reserved").Update("status", "consumed").Error; err != nil {
@@ -2752,9 +3053,13 @@ func (s *DeliveryService) launchRollbackJob(ctx context.Context, task *model.Del
 	if err := s.db.WithContext(ctx).Save(&rollback).Error; err != nil {
 		return s.markRollbackFailed(ctx, task.ID, "cannot persist rollback job: "+err.Error())
 	}
+	rollbackLimit := task.TargetHosts
+	if strings.TrimSpace(rollbackLimit) == "" {
+		rollbackLimit = task.TargetHost
+	}
 	job, err := s.awx.Launch(ctx, s.cfg.RollbackTemplateID, AWXLaunchRequest{
 		InventoryID: target.AWXInventoryID,
-		Limit:       task.TargetHost,
+		Limit:       rollbackLimit,
 		ExtraVars:   rollbackExtraVars(task, payload),
 	})
 	if err != nil {
@@ -2834,8 +3139,12 @@ func (s *DeliveryService) AcknowledgeRollbackRelease(ctx context.Context, taskID
 }
 
 func rollbackExtraVars(task *model.DeliveryTask, payload deliveryPayload) map[string]any {
+	hosts := task.TargetHosts
+	if strings.TrimSpace(hosts) == "" {
+		hosts = task.TargetHost
+	}
 	return map[string]any{
-		"target_hosts":  task.TargetHost,
+		"target_hosts":  hosts,
 		"instance_name": payload.InstanceName,
 		"data_disk":     payload.DataDisk,
 		"task_id":       task.ID,
diff --git a/server/internal/service/delivery_test.go b/server/internal/service/delivery_test.go
index 006e2ce..a197443 100644
--- a/server/internal/service/delivery_test.go
+++ b/server/internal/service/delivery_test.go
@@ -53,6 +53,21 @@ func TestValidateDeliveryInput(t *testing.T) {
 	if err := validateDeliveryInput(lts, dataDisks); err != nil {
 		t.Fatalf("8.4 LTS rejected: %v", err)
 	}
+	replica := valid
+	replica.Topology = "primary_replica"
+	replica.ReplicaCount = 3
+	replica.TargetHosts = []string{"db-01", "db-02", "db-03", "db-04"}
+	if err := validateDeliveryInput(replica, dataDisks); err != nil {
+		t.Fatalf("primary_replica input rejected: %v", err)
+	}
+	if got := topologyNodeCount(replica); got != 4 {
+		t.Fatalf("topologyNodeCount = %d, want 4", got)
+	}
+	tooManyReplicas := replica
+	tooManyReplicas.ReplicaCount = 8
+	if err := validateDeliveryInput(tooManyReplicas, dataDisks); err == nil {
+		t.Fatal("replica_count 8 was accepted")
+	}
 	for name, mutate := range map[string]func(*MySQLDeliveryInput){
 		"uppercase namespace":  func(in *MySQLDeliveryInput) { in.Namespace = "Team-A" },
 		"bad instance":         func(in *MySQLDeliveryInput) { in.InstanceName = "mysql_01" },
@@ -123,6 +138,35 @@ func TestFirstFreeHost(t *testing.T) {
 	}
 }
 
+func TestResolvePinnedPrimaryReplicaNodes(t *testing.T) {
+	pool := []targetHost{{Name: "node-a", IP: "10.0.0.1"}, {Name: "node-b", IP: "10.0.0.2"}, {Name: "node-c", IP: "10.0.0.3"}}
+
+	// 主节点不是池首空闲节点（firstFreeHost 会选 node-a）：首节点必须以用户列表为准。
+	nodes, validationMsg, err := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-c", "node-a"}, nil, 4, 2, "")
+	if err != nil || validationMsg != "" {
+		t.Fatalf("unexpected rejection: msg=%q err=%v", validationMsg, err)
+	}
+	if nodes[0].Name != "node-c" || nodes[0].IP != "10.0.0.3" || nodes[1].Name != "node-a" {
+		t.Fatalf("primary must follow the user-specified order, got %+v", nodes)
+	}
+
+	if _, msg, _ := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-a"}, nil, 4, 2, ""); msg == "" {
+		t.Fatal("host count mismatch was accepted")
+	}
+	if _, msg, _ := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-a", "node-x"}, nil, 4, 2, ""); msg == "" {
+		t.Fatal("host outside the pool was accepted")
+	}
+	if _, msg, _ := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-a", "node-a"}, nil, 4, 2, ""); msg == "" {
+		t.Fatal("duplicate host was accepted")
+	}
+	if _, msg, _ := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-b", "node-c"}, nil, 4, 2, "node-a"); msg == "" {
+		t.Fatal("target_host mismatching the first entry was accepted")
+	}
+	if _, _, err := resolvePinnedPrimaryReplicaNodes(pool, []string{"node-a", "node-b"}, []string{"node-b"}, 1, 2, ""); err == nil {
+		t.Fatal("saturated pinned host must defer scheduling")
+	}
+}
+
 func TestAllocatePort(t *testing.T) {
 	if port, err := allocatePort(0, nil); err != nil || port != mysqlPortPoolStart {
 		t.Fatalf("expected first pool port %d, got %d err=%v", mysqlPortPoolStart, port, err)