aws-cloudformation - "Importing"不可将资源导入 CloudFormation 堆栈

Question

借助 AWS CloudFormation，您可以导入 supported types 的现有资源到新的或现有的堆栈中。不支持某些资源，例如路由以及各种关联和附件。我猜其中许多都不是“成熟的”资源，它们只是作为另一个资源的组件存在于幕后。

我发现，只需将现有 VPCGatewayAttachment 添加到模板中，并在通过 IMPORT ChangeSet 成功导入 VPC 和 Internet 网关后创建并执行 UPDATE ChangeSet，即可“假导入”现有 VPCGatewayAttachment。 VPCGatewayAttachment 添加时没有错误，并且也成为堆栈的一部分。在下面的演示中，您可以注意到相关 VPCGatewayAttachment 的 PhysicalResourceId 在其初始创建和随后的删除并重新添加到堆栈之间发生变化。 (注意:通过模板进行初始创建是为了简化示例——通常这将是不在堆栈中的现有资源)。我不确定这是否反射(reflect)了现有附件的实际破坏并重新创建了新附件，或者只是附件没有实际的 PhysicalResourceId，而是在添加到堆栈时随机分配的。

我的问题是:

1. VPCGatewayAttachment 的“虚假导入”在生产环境中是否是非破坏性的，即不会造成中断？

2. 如果是无中断的，那么哪些其他不支持导入的资源也可以使用相同的技术以无中断的方式有效地引入堆栈:只需在模板中添加等效资源创建并执行 UPDATE ChangeSet。我主要考虑的是路线以及其他关联和附件。

下面是对此的演示。要运行它，请将前 4 个文件(.ps1 和 .yaml)放置在同一目录中具有指定名称的文件中。您必须为配置文件安装并配置 AWS CLI，并具有操作堆栈和资源的适当权限。运行 PowerShell (.ps1) 文件。您可能希望将 S3 存储桶的名称替换为唯一的名称。该脚本会清理所有创建的资源(堆栈和 s3 存储桶)。

如果您想跳过运行它，我已将本地运行的输出作为下面的最后一个文件包含在内。

case-XXXXXXXXXX-example.ps1:

echo "---------------------------------------------------------------------------"
echo "---------------------------------------------------------------------------"
echo "- Demonstration for Case XXXXXXXXXX"
echo "---------------------------------------------------------------------------"
echo "---------------------------------------------------------------------------"
echo "-"
echo "---------------------------------------------------------------------------"
echo "Create S3 bucket and upload templates"
echo "---------------------------------------------------------------------------"
aws s3api create-bucket --bucket case-XXXXXXXXXX --no-paginate --no-cli-pager
aws s3 sync . s3://case-XXXXXXXXXX --exclude * --include *.yaml --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- Create stack with VPC, Internet Gateway, and Gateway Attachment"
echo "-  (the latter has DeletionPolicy: Retain)"
echo "---------------------------------------------------------------------------"
echo "- Create stack"
aws cloudformation create-stack --stack-name case-XXXXXXXXXX --template-url https://case-XXXXXXXXXX.s3.amazonaws.com/case-XXXXXXXXXX-example-1.yaml --no-paginate --no-cli-pager
echo "- Wait stack create complete"
aws cloudformation wait stack-create-complete --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
echo "- Describe stack and resources"
echo "- Note the PhysicalResourceId of the Gateway Attachment."
aws cloudformation describe-stacks --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
aws cloudformation describe-stack-resources --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- Create and execute a change-set that removes the Gateway Attachment"
echo "- This leaves us in a state simulating having IMPORTed the VPC and"
echo "- Internet Gateway, but the Gateway Attachment is not in the stack."
echo "- This sets up the next part which actually demonstrates a 'fake import'"
echo "- of the Gateway Attachment"
echo "---------------------------------------------------------------------------"
echo "- Create change-set"
aws cloudformation create-change-set --stack-name case-XXXXXXXXXX --change-set-name delete-igw-attach --template-url https://case-XXXXXXXXXX.s3.amazonaws.com/case-XXXXXXXXXX-example-2.yaml --no-paginate --no-cli-pager
echo "- Wait change-set create complete"
aws cloudformation wait change-set-create-complete --stack-name case-XXXXXXXXXX --change-set-name delete-igw-attach --no-paginate --no-cli-pager
echo "- Describe change-set"
aws cloudformation describe-change-set --stack-name case-XXXXXXXXXX --change-set-name delete-igw-attach --no-paginate --no-cli-pager
echo "- Execute change-set"
aws cloudformation execute-change-set --stack-name case-XXXXXXXXXX --change-set-name delete-igw-attach --no-paginate --no-cli-pager
echo "- Wait stack update complete"
aws cloudformation wait stack-update-complete  --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
echo "---------------------------------------------------------------------------"
echo "- Note the Gateway Attachment is not in the stack, but the Internet Gateway"
echo "- is still attached to the VPC"
echo "---------------------------------------------------------------------------"
aws cloudformation describe-stack-resources --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
aws ec2 describe-internet-gateways --filter "Name=tag:Name,Values=Case-XXXXXXXXXX" --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- THE WHOLE POINT OF THIS DEMONSTRATION IS NEXT"
echo "- 'Fake Import' the Gateway Attachment just by adding it to the template and"
echo "- creating and executing an UPDATE change-set."
echo "---------------------------------------------------------------------------"
echo "- Create change-set"
aws cloudformation create-change-set --stack-name case-XXXXXXXXXX --change-set-name fake-import-igw-attach --template-url https://case-XXXXXXXXXX.s3.amazonaws.com/case-XXXXXXXXXX-example-3.yaml --no-paginate --no-cli-pager
echo "- Wait change-set create complete"
aws cloudformation wait change-set-create-complete --stack-name case-XXXXXXXXXX --change-set-name fake-import-igw-attach --no-paginate --no-cli-pager
echo "- Describe change-set"
aws cloudformation describe-change-set --stack-name case-XXXXXXXXXX --change-set-name fake-import-igw-attach --no-paginate --no-cli-pager
echo "- Execute change-set"
aws cloudformation execute-change-set --stack-name case-XXXXXXXXXX --change-set-name fake-import-igw-attach  --no-paginate --no-cli-pager
echo "- Wait stack update complete"
aws cloudformation wait stack-update-complete  --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
echo "---------------------------------------------------------------------------"
echo "- Note that the Gateway Attachment is now in the stack and the Internet"
echo "- Gateway is still attached, and there weren't any errors."
echo "- The PhysicalResourceId did change, however."
echo "---------------------------------------------------------------------------"
aws cloudformation describe-stack-resources --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
aws ec2 describe-internet-gateways --filter "Name=tag:Name,Values=Case-XXXXXXXXXX" --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- Delete stack"
echo "---------------------------------------------------------------------------"
aws cloudformation delete-stack --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager
echo "- Wait stack delete complete"
aws cloudformation wait stack-delete-complete --stack-name case-XXXXXXXXXX --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- Delete S3 bucket with templates"
echo "---------------------------------------------------------------------------"
aws s3 rb s3://case-XXXXXXXXXX --force --no-paginate --no-cli-pager

echo "---------------------------------------------------------------------------"
echo "- DONE"
echo "---------------------------------------------------------------------------"

case-XXXXXXXXXX-example-1.yaml

Description: >
  Create the VPC, Internet Gateway, and attach the gateway 
  to the VPC, with a DeletionPolicy of Retain so that we can
  remove it from the stack without deleting it.  Run with
  aws cloudformation create-stack.

Resources:
  VPC:
    Type:  AWS::EC2::VPC
    Properties:
      CidrBlock: 10.187.32.0/24
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

  IGW:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

  IGWassoc:
    Type: AWS::EC2::VPCGatewayAttachment
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref IGW

case-XXXXXXXXXX-example-2.yaml

Description: >
  Delete the gateway attachment, but it will be retained 
  so we can import it next. Run with aws cloudformation
  create-change-set --change-set-type UPDATE

Resources:
  VPC:
    Type:  AWS::EC2::VPC
    Properties:
      CidrBlock: 10.187.32.0/24
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

  IGW:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

case-XXXXXXXXXX-example3.yaml

Description: >
  Create the gateway attachment.  It already exists, and is
  not importable but this action succeeds and SEEMS to be
  non-destructive. Run with aws cloudformation
  create-change-set --change-set-type UPDATE

Resources:
  VPC:
    Type:  AWS::EC2::VPC
    Properties:
      CidrBlock: 10.187.32.0/24
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

  IGW:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
      - Key: Name
        Value: Case-XXXXXXXXXX

  IGWassoc:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref IGW

输出.txt

---------------------------------------------------------------------------
---------------------------------------------------------------------------
- Demonstration for Case XXXXXXXXXX
---------------------------------------------------------------------------
---------------------------------------------------------------------------
-
---------------------------------------------------------------------------
Create S3 bucket and upload templates
---------------------------------------------------------------------------
{
    "Location": "/case-XXXXXXXXXX"
}
upload: .\case-XXXXXXXXXX-example-2.yaml to s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-2.yaml
upload: .\case-XXXXXXXXXX-example-1.yaml to s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-1.yaml
upload: .\case-XXXXXXXXXX-example-3.yaml to s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-3.yaml
---------------------------------------------------------------------------
- Create stack with VPC, Internet Gateway, and Gateway Attachment
-  (the latter has DeletionPolicy: Retain)
---------------------------------------------------------------------------
- Create stack
{   
    "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829"
}
- Wait stack create complete
- Describe stack and resources
- Note the PhysicalResourceId of the Gateway Attachment.
{   
    "Stacks": [
        {
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "StackName": "case-XXXXXXXXXX",
            "Description": "Create the VPC, Internet Gateway, and attach the gateway  to the VPC, with a DeletionPolicy of Retain so that we can remove it from the stack without deleting it.  Run with aws cloudformation create-stack.\n",
            "CreationTime": "2021-11-03T15:05:03.251000+00:00",
            "RollbackConfiguration": {},
            "StackStatus": "CREATE_COMPLETE",
            "DisableRollback": false,
            "NotificationARNs": [],
            "Tags": [],
            "EnableTerminationProtection": false,
            "DriftInformation": {
                "StackDriftStatus": "NOT_CHECKED"
            }
        }
    ]
}
{   
    "StackResources": [
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "IGW",
            "PhysicalResourceId": "igw-028cb469265fa34a8",
            "ResourceType": "AWS::EC2::InternetGateway",
            "Timestamp": "2021-11-03T15:05:49.880000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        },
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "IGWassoc",
            "PhysicalResourceId": "case-IGWas-ZHZQ0DZ9KXLS",
            "ResourceType": "AWS::EC2::VPCGatewayAttachment",
            "Timestamp": "2021-11-03T15:06:08.293000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        },
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "VPC",
            "PhysicalResourceId": "vpc-03b26a31ca1bca800",
            "ResourceType": "AWS::EC2::VPC",
            "Timestamp": "2021-11-03T15:05:28.179000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        }
    ]
}
---------------------------------------------------------------------------
- Create and execute a change-set that removes the Gateway Attachment
- This leaves us in a state simulating having IMPORTed the VPC and
- Internet Gateway, but the Gateway Attachment is not in the stack.
- This sets up the next part which actually demonstrates a 'fake import'
- of the Gateway Attachment
---------------------------------------------------------------------------
- Create change-set
{
    "Id": "arn:aws:cloudformation:us-east-1:606679984871:changeSet/delete-igw-attach/631b12ca-c8f4-407d-b248-b2766a730eba",
    "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829"
}
- Wait change-set create complete
- Describe change-set
{
    "ChangeSetName": "delete-igw-attach",
    "ChangeSetId": "arn:aws:cloudformation:us-east-1:606679984871:changeSet/delete-igw-attach/631b12ca-c8f4-407d-b248-b2766a730eba",
    "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
    "StackName": "case-XXXXXXXXXX",
    "CreationTime": "2021-11-03T15:06:40.618000+00:00",
    "ExecutionStatus": "AVAILABLE",
    "Status": "CREATE_COMPLETE",
    "NotificationARNs": [],
    "RollbackConfiguration": {},
    "Capabilities": [],
    "Changes": [
        {
            "Type": "Resource",
            "ResourceChange": {
                "Action": "Remove",
                "LogicalResourceId": "IGWassoc",
                "PhysicalResourceId": "case-IGWas-ZHZQ0DZ9KXLS",
                "ResourceType": "AWS::EC2::VPCGatewayAttachment",
                "Scope": [],
                "Details": []
            }
        }
    ],
    "IncludeNestedStacks": false
}
- Execute change-set
- Wait stack update complete
---------------------------------------------------------------------------
- Note the Gateway Attachment is not in the stack, but the Internet Gateway
- is still attached to the VPC
---------------------------------------------------------------------------
{
    "StackResources": [
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "IGW",
            "PhysicalResourceId": "igw-028cb469265fa34a8",
            "ResourceType": "AWS::EC2::InternetGateway",
            "Timestamp": "2021-11-03T15:05:49.880000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        },
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "VPC",
            "PhysicalResourceId": "vpc-03b26a31ca1bca800",
            "ResourceType": "AWS::EC2::VPC",
            "Timestamp": "2021-11-03T15:05:28.179000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        }
    ]
}
{
    "InternetGateways": [
        {
            "Attachments": [
                {
                    "State": "available",
                    "VpcId": "vpc-03b26a31ca1bca800"
                }
            ],
            "InternetGatewayId": "igw-028cb469265fa34a8",
            "OwnerId": "606679984871",
            "Tags": [
                {
                    "Key": "aws:cloudformation:logical-id",
                    "Value": "IGW"
                },
                {
                    "Key": "Name",
                    "Value": "Case-XXXXXXXXXX"
                },
                {
                    "Key": "aws:cloudformation:stack-name",
                    "Value": "case-XXXXXXXXXX"
                },
                {
                    "Key": "aws:cloudformation:stack-id",
                    "Value": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829"
                }
            ]
        }
    ]
}
---------------------------------------------------------------------------
- THE WHOLE POINT OF THIS DEMONSTRATION IS NEXT
- 'Fake Import' the Gateway Attachment just by adding it to the template and
- creating and executing an UPDATE change-set.
---------------------------------------------------------------------------
- Create change-set
{
    "Id": "arn:aws:cloudformation:us-east-1:606679984871:changeSet/fake-import-igw-attach/95510e17-3f44-4ba4-be9e-4183cbb143ca",
    "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829"
}
- Wait change-set create complete
- Describe change-set
{
    "ChangeSetName": "fake-import-igw-attach",
    "ChangeSetId": "arn:aws:cloudformation:us-east-1:606679984871:changeSet/fake-import-igw-attach/95510e17-3f44-4ba4-be9e-4183cbb143ca",
    "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
    "StackName": "case-XXXXXXXXXX",
    "CreationTime": "2021-11-03T15:07:52.172000+00:00",
    "ExecutionStatus": "AVAILABLE",
    "Status": "CREATE_COMPLETE",
    "NotificationARNs": [],
    "RollbackConfiguration": {},
    "Capabilities": [],
    "Changes": [
        {
            "Type": "Resource",
            "ResourceChange": {
                "Action": "Add",
                "LogicalResourceId": "IGWassoc",
                "ResourceType": "AWS::EC2::VPCGatewayAttachment",
                "Scope": [],
                "Details": []
            }
        }
    ],
    "IncludeNestedStacks": false
}
- Execute change-set
- Wait stack update complete
---------------------------------------------------------------------------
- Note that the Gateway Attachment is now in the stack and the Internet
- Gateway is still attached, and there weren't any errors.
- The PhysicalResourceId did change, however.
---------------------------------------------------------------------------
{
    "StackResources": [
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "IGW",
            "PhysicalResourceId": "igw-028cb469265fa34a8",
            "ResourceType": "AWS::EC2::InternetGateway",
            "Timestamp": "2021-11-03T15:05:49.880000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        },
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "IGWassoc",
            "PhysicalResourceId": "case-IGWas-3DBXKEM6SFPL",
            "ResourceType": "AWS::EC2::VPCGatewayAttachment",
            "Timestamp": "2021-11-03T15:08:48.657000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        },
        {
            "StackName": "case-XXXXXXXXXX",
            "StackId": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829",
            "LogicalResourceId": "VPC",
            "PhysicalResourceId": "vpc-03b26a31ca1bca800",
            "ResourceType": "AWS::EC2::VPC",
            "Timestamp": "2021-11-03T15:05:28.179000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "DriftInformation": {
                "StackResourceDriftStatus": "NOT_CHECKED"
            }
        }
    ]
}
{
    "InternetGateways": [
        {
            "Attachments": [
                {
                    "State": "available",
                    "VpcId": "vpc-03b26a31ca1bca800"
                }
            ],
            "InternetGatewayId": "igw-028cb469265fa34a8",
            "OwnerId": "606679984871",
            "Tags": [
                {
                    "Key": "aws:cloudformation:logical-id",
                    "Value": "IGW"
                },
                {
                    "Key": "Name",
                    "Value": "Case-XXXXXXXXXX"
                },
                {
                    "Key": "aws:cloudformation:stack-name",
                    "Value": "case-XXXXXXXXXX"
                },
                {
                    "Key": "aws:cloudformation:stack-id",
                    "Value": "arn:aws:cloudformation:us-east-1:606679984871:stack/case-XXXXXXXXXX/6bf590e0-3cb7-11ec-b30d-0a5d84963829"
                }
            ]
        }
    ]
}
---------------------------------------------------------------------------
- Delete stack
---------------------------------------------------------------------------
- Wait stack delete complete
---------------------------------------------------------------------------
- Delete S3 bucket with templates
---------------------------------------------------------------------------
delete: s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-3.yaml
delete: s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-2.yaml
delete: s3://case-XXXXXXXXXX/case-XXXXXXXXXX-example-1.yaml
remove_bucket: case-XXXXXXXXXX
---------------------------------------------------------------------------
- DONE
---------------------------------------------------------------------------

Answer 1

尝试使用 AWS::EC2::Route 进行此操作，但失败并显示“路由已存在”。

因此，虽然我可能能够通过将 VPCGatewayAttachment 强行添加到堆栈中来逃脱惩罚，但我无法使用路由以及可能的其他资源类型。

对于未记录的方法来说，花费时间来研究可能有哪些资源是不值得的。

将资源放入不支持导入的堆栈中的最佳方法是使用一个脚本来删除现有的不可导入资源并使用更改集重新创建它们。这必须在维护窗口期间完成，因为非冗余系统肯定会出现中断。