DeletionPolicy:Snapshot 无法为集群实例指定，请改用集群上的删除策略

Question

我正在尝试使用下面的 cloudoformation 模板创建 RDS 集群和 aurora 实例：

{
      "AWSTemplateFormatVersion" : "2010-09-09",

  "Description" : "example setup",

  "Parameters" : {
    "DBInstanceIdentifier" : {
      "Type": "String",
      "Description": "Name for the DB instance."
    },
    "DBUser" : {
      "Type": "String",
      "Description": "Master user"
    },
    "DBPassword" : {
      "Type": "String",
      "Description": "Pass"
    },
    "DBModel" : {
      "Type": "String",
      "Description": "Instance model to be used for the DB."
    }
  },


  "Resources": {
    "RDSCluster": {
      "Type": "AWS::RDS::DBCluster",
      "Properties": {
        "MasterUsername": { "Ref" : "DBUser" },
        "MasterUserPassword": { "Ref" : "DBPassword" },
        "Engine": "aurora",
        "DBClusterParameterGroupName": "default.aurora5.6",
        "VpcSecurityGroupIds": [{"Fn::GetAtt" : [ "DBFromSiteSecurityGroup" , "GroupId" ]}]
      }
    },
    "AuroraInstance": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "DBInstanceIdentifier": { "Ref" : "DBInstanceIdentifier" },
        "DBParameterGroupName": "default.aurora5.6",
        "Engine": "aurora",
        "DBClusterIdentifier": {
          "Ref": "RDSCluster"
        },
        "PubliclyAccessible": "true",
        "DBInstanceClass": { "Ref" : "DBModel" }
      }
    },

    "DBFromSiteSecurityGroup" : {
       "Type" : "AWS::EC2::SecurityGroup",
       "Properties" : {
          "GroupDescription" : "Enable MySQL",
          "SecurityGroupIngress" : [
             {"IpProtocol" : "tcp", "FromPort" : "3306", "ToPort" : "3306", "CidrIp" : "195.171.102.98/32"}
          ]
       }
    },
     "DBFromSiteSecurityGroupIngress1" : {
         "Type" : "AWS::EC2::SecurityGroupIngress",
         "Properties" : {
             "GroupName" : { "Ref" : "DBFromSiteSecurityGroup" },
             "IpProtocol" : "tcp",
             "ToPort" : "3306",
             "FromPort" : "3306",
             "SourceSecurityGroupName" : { "Ref" : "DBFromSiteSecurityGroup" }
         }
     }
  }
}

我传递的db_model参数是"db.t2.medium"。集群在 cloudformation 控制台中成功创建，但是 AWS::RDS::DBInstance 创建失败并出现以下错误

"DeletionPolicy:Snapshot cannot be specified for a cluster instance, use deletion policy on the cluster instead."

更奇怪的是，当我在欧盟伦敦地区尝试运行相同的 CF 模板时，它工作正常！！！欧盟爱尔兰地区和极光有问题吗？

Answer 1

来自 AWS 支持

This is a known issue and has been reported by other customers as well. The service team is currently working on the fix for this but there is no ETA as to when that would be pushed.

The work-around in the meanwhile is to specify a DeletionPolicy inside the DB instance resource definition that is failing to create, with the value of 'Delete'. [1]

An example below:

"Resources": { 
    "Database1": { 
        "DeletionPolicy": "Delete", 
        "Properties": {...}, 
        "Type": "AWS::RDS::DBInstance" 
    } 
}

References: [1] DeletionPolicy - http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html#w2ab2c19c23c11c17

Answer 2

来自 AWS Support 的更新：

When creating an Amazon Aurora DBInstance in a DB Cluster using AWS CloudFormation, CloudFormation applies a default Deletion policy of “Delete”, if a deletion policy is not specified. If a Deletion Policy of “Snapshot” is specified for an Amazon Aurora DBInstance, CloudFormation returns an error, because instances in a DB Cluster cannot be snapshotted individually; Snapshotting must be done at the DB Cluster level.

As part of a recent deployment, we inadvertently changed the default deletion policy for an Amazon Aurora DBInstance to “Snapshot”. This caused our template validation to fail. To remedy this, CloudFormation is reverting the value of default DeletionPolicy for Amazon Aurora DBInstances to “Delete”. This fix will be completed by 21st July, 2017. Until this fix is completely rolled out, customers can explicitly override our incorrect defaults by specifying a deletion policy of “Delete” for Amazon Aurora DBInstances.

We have corrected the gap in our testing that led to this situation, and will continue to improve our testing to prevent recurrences. We recognize how critical it is for us to preserve existing behavior for our customers, and apologize for this inconvenience.

DeletionPolicy:Snapshot 无法为集群实例指定，请改用集群上的删除策略

DeletionPolicy:Snapshot cannot be specified for a cluster instance, use deletion policy on the cluster instead

amazon-web-services

amazon-rds

amazon-cloudformation

amazon-aurora