# 使用 AWS Command Line Interface v2 处理具有最终一致性（MREC）的 DynamoDB 全局表和多区域复制
<a name="example_dynamodb_Scenario_MultiRegionReplication_section"></a>

以下代码示例显示如何使用具有最终一致性的多区域复制（MREC）来管理 DynamoDB 全局表。
+ 使用多区域复制（MREC）创建表。
+ 从副本表中放置和获取项目。
+ 逐一移除副本。
+ 通过删除表来进行清除。

------
#### [ Bash ]

**AWS CLI 及 Bash 脚本**  
使用多区域复制来创建表。  

```
# Step 1: Create a new table (MusicTable) in US East (Ohio), with DynamoDB Streams enabled (NEW_AND_OLD_IMAGES)
aws dynamodb create-table \
    --table-name MusicTable \
    --attribute-definitions \
        AttributeName=Artist,AttributeType=S \
        AttributeName=SongTitle,AttributeType=S \
    --key-schema \
        AttributeName=Artist,KeyType=HASH \
        AttributeName=SongTitle,KeyType=RANGE \
    --billing-mode PAY_PER_REQUEST \
    --stream-specification StreamEnabled=true,StreamViewType=NEW_AND_OLD_IMAGES \
    --region us-east-2

# Step 2: Create an identical MusicTable table in US East (N. Virginia)
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Create": {
        "RegionName": "us-east-1"
      }
    }
  ]
}' \
--region us-east-2

# Step 3: Create a table in Europe (Ireland)
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Create": {
        "RegionName": "eu-west-1"
      }
    }
  ]
}' \
--region us-east-2
```
描述多区域表。  

```
# Step 4: View the list of replicas created using describe-table
aws dynamodb describe-table \
    --table-name MusicTable \
    --region us-east-2 \
    --query 'Table.{TableName:TableName,TableStatus:TableStatus,MultiRegionConsistency:MultiRegionConsistency,Replicas:Replicas[*].{Region:RegionName,Status:ReplicaStatus}}'
```
将项目放在副本表中。  

```
# Step 5: To verify that replication is working, add a new item to the Music table in US East (Ohio)
aws dynamodb put-item \
    --table-name MusicTable \
    --item '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region us-east-2
```
从副本表中获取项目。  

```
# Step 6: Wait for a few seconds, and then check to see whether the item has been 
# successfully replicated to US East (N. Virginia) and Europe (Ireland)
aws dynamodb get-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region us-east-1

aws dynamodb get-item \
    --table-name MusicTable \
    --key '{"Artist": {"S":"item_1"},"SongTitle": {"S":"Song Value 1"}}' \
    --region eu-west-1
```
移除副本。  

```
# Step 7: Delete the replica table in Europe (Ireland) Region
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Delete": {
        "RegionName": "eu-west-1"
      }
    }
  ]
}' \
--region us-east-2

# Delete the replica table in US East (N. Virginia) Region
aws dynamodb update-table --table-name MusicTable --cli-input-json \
'{
  "ReplicaUpdates":
  [
    {
      "Delete": {
        "RegionName": "us-east-1"
      }
    }
  ]
}' \
--region us-east-2
```
通过删除表来进行清除。  

```
# Clean up: Delete the primary table
aws dynamodb delete-table --table-name MusicTable --region us-east-2

echo "Global table demonstration complete."
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的以下主题。
  + [CreateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/CreateTable)
  + [DeleteTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DeleteTable)
  + [DescribeTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DescribeTable)
  + [GetItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/GetItem)
  + [PutItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/PutItem)
  + [UpdateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/UpdateTable)

------

有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。