# 创建MRS集群
#### 场景描述
本章节指导用户通过API创建一个MRS分析集群。API的调用方法请参见[如何调用API](https://support.huaweicloud.com/api-mrs/mrs_02_0008.html)。
#### 约束限制
- 已在待创建集群区域通过虚拟私有云服务创建VPC，子网。创建VPC请参考[查询VPC列表](https://support.huaweicloud.com/api-vpc/vpc_api01_0003.html)和[创建VPC](https://support.huaweicloud.com/api-vpc/vpc_api01_0001.html)。创建子网请参考[查询子网列表](https://support.huaweicloud.com/api-vpc/vpc_subnet01_0003.html)和[创建子网](https://support.huaweicloud.com/api-vpc/vpc_subnet01_0001.html)。
- 已获取待创建集群区域的区域和可用区信息，具体请参考[终端节点](https://support.huaweicloud.com/api-mrs/mrs_02_0001.html#mrs_02_0001__zh-cn_topic_0264280009_section17316828876)。
- 已获取待创建集群区域的项目ID，请参考[获取项目ID](https://support.huaweicloud.com/api-mrs/mrs_02_0011.html)获取。
- 已确定待创建集群的版本及版本支持的组件信息，请参见[MRS组件版本一览表](https://support.huaweicloud.com/productdesc-mrs/mrs_08_0005.html)。
- 该示例创建出来的是按需购买的分析集群。
 
#### 操作步骤
- 接口相关信息 URI格式：POST /v2/{project_id}/clusters
  详情请参见[创建集群](https://support.huaweicloud.com/api-mrs/mrs_02_0101.html)。
  
- 请求示例 POST: https://*{endpoint}* /v2/*{project_id}*/clusters
  - {endpoint}信息具体请参考[终端节点](https://support.huaweicloud.com/api-mrs/mrs_02_0001.html#mrs_02_0001__zh-cn_topic_0264280009_section17316828876)。
  
  - {project_id}信息请通过[获取项目ID](https://support.huaweicloud.com/api-mrs/mrs_02_0011.html)获取。
  
  - 节点的实例规格参数"node_size"建议从MRS控制台的集群创建页面获取对应区域对应版本所支持的规格。
  
  
  Body：
  ```
  {
    "cluster_version": "MRS 3.2.0-LTS.1",
    "cluster_name": "mrs_Demo",
    "cluster_type": "ANALYSIS",
    "charge_info": {
    "charge_mode": "postPaid"
    },
    "region": "",
    "availability_zone": "",
    "vpc_name": "vpc-37cd",
    "subnet_name": "subnet-ed99",
    "components": "Hadoop,Spark2x,HBase,Hive,Hue,Flink,Oozie,Ranger,Tez",
    "safe_mode": "KERBEROS",
    "manager_admin_password": "xxx",
    "login_mode": "PASSWORD",
    "node_root_password": "xxx",
    "log_collection": 1,
    "mrs_ecs_default_agency": "MRS_ECS_DEFAULT_AGENCY",
    "tags": [
      {
        "key": "tag1",
        "value": "111"
      },
      {
        "key": "tag2",
        "value": "222"
      }
    ], 
    "node_groups": [
      {
        "group_name": "master_node_default_group",
        "node_num": 2,
        "node_size": "rc3.4xlarge.4.linux.bigdata",
        "root_volume": {
          "type": "SAS",
          "size": 480
        },
        "data_volume": {
          "type": "SAS",
          "size": 600
        },
        "data_volume_count": 1
      },
     {
        "group_name": "core_node_analysis_group",
        "node_num": 3,
        "node_size": "rc3.4xlarge.4.linux.bigdata",
        "root_volume": {
          "type": "SAS",
          "size": 480
        },
        "data_volume": {
          "type": "SAS",
          "size": 600
        },
        "data_volume_count": 1
      },
      {
        "group_name": "task_node_analysis_group",
        "node_num": 3,
        "node_size": "rc3.4xlarge.4.linux.bigdata",
        "root_volume": {
          "type": "SAS",
          "size": 480
        },
        "data_volume": {
          "type": "SAS",
          "size": 600
        },
        "data_volume_count": 1,
   "auto_scaling_policy": {
                  "auto_scaling_enable": true,
                  "min_capacity": 0,
                  "max_capacity": 1,
                  "resources_plans": [],
                  "exec_scripts": [],
                  "rules": [
                      {
                          "name": "default-expand-1",
                          "description": "",
                          "adjustment_type": "scale_out",
                          "cool_down_minutes": 5,
                          "scaling_adjustment": "1",
                          "trigger": {
                              "metric_id": 2003,
                              "metric_name": "StormSlotAvailablePercentage",
                              "metric_value": 100,
                              "comparison_operator_id": 2003,
                              "comparison_operator": "LTOE",
                              "evaluation_periods": "1"
                          }
                      }
                  ]
              }
      }
    ]
  }
  ```
  参数详细信息请参考[创建集群](https://support.huaweicloud.com/api-mrs/mrs_02_0101.html)获取。
  
- 响应示例
  ```
  {
  "cluster_id": "da1592c2-bb7e-468d-9ac9-83246e95447a"
  }
  ```