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Object Storage Service:CRR across accounts

Last Updated:Apr 02, 2024

Cross-region replication (CRR) across accounts allows the automatic and asynchronous (near real-time) replication of Object Storage Service (OSS) objects from a bucket in a region within an Alibaba Cloud account to another bucket in another region within another Alibaba Cloud account. CRR across accounts replicates operations, such as the creation, overwriting, and deletion of objects, from a source bucket to a destination bucket. This topic describes how to perform CRR across accounts.

Prerequisites

  • Bucket A, which works as the source bucket of the CRR task, is created in a region within Account A. The UID of Account A, the name of Bucket A, and the region in which Bucket A is located are recorded.

  • Bucket B, which works as the destination bucket of the CRR task, is created in another region within Account B. The UID of Account B, the name of Bucket B, and the region in which Bucket B is located are recorded.

Procedure

Use the OSS console

  1. Use Account A to perform the following operations:

    1. Create a normal service role.

      Important

      You can create a RAM role by using a RAM user. The RAM user must have the following permissions: ram:CreateRole, ram:GetRole, ram:ListPoliciesForRole, and ram:AttachPolicyToRole. However, it is risky to grant a RAM user permissions such as ram:CreateRole and ram:GetRole. You can use the Alibaba Cloud account with which the RAM user is associated to create a RAM role and grant the required permissions to the RAM role. Then, the RAM user can assume the RAM role that is created by the Alibaba Cloud account.

      When you create a normal service role, set Select Trusted Entity to Alibaba Cloud Service, Role Type to Normal Service Role, and Select Trusted Service to OSS. For more information, see Create a regular service role.

    2. Grant the RAM role the permissions to perform CRR on the source bucket.

      You can use one of the following methods to grant the permissions to the RAM role:

      Attach the required system policy to the RAM role

      Warning

      Attach the AliyunOSSFullAccess system policy to the RAM role. The RAM role to which the AliyunOSSFullAccess system policy is attached has the permissions to perform all operations on all buckets within the current Alibaba Cloud account. Exercise caution when you attach the system policy to the RAM role.

      For more information, see Grant permissions to a RAM role.

      Attach a custom policy to the RAM role

      You can use a RAM policy to grant the RAM role the minimum permissions required to perform CRR on the source bucket.

      Note

      Replace src-bucket with the name of the source bucket based on your business requirements.

      {
         "Version":"1",
         "Statement":[
            {
               "Effect":"Allow",
               "Action":[
                  "oss:ReplicateList",
                  "oss:ReplicateGet"
               ],
               "Resource":[
                  "acs:oss:*:*:src-bucket",          	
                  "acs:oss:*:*:src-bucket/*"
               ]
            }
         ]
      }

      For more information, see Grant permissions to a RAM role.

  2. Use Account B to grant the RAM role the permissions to receive the objects that you want to replicate to the destination bucket.

    Method 1: (Recommended) Add in GUI

    1. Log on to the OSS console.

    2. In the left-side navigation pane, click Buckets. On the Buckets page, find the bucket named dest-bucket and click the bucket name.

    3. In the left-side navigation tree, choose Permission Control > Bucket Policy.

    4. On the Bucket Policy tab, click Add in GUI and then click Receive Objects to Replicate.

    5. In the Receive Objects to Replicate panel, set Obtain UID and RAM Role From to Source RAM role ARN for replication, and select the ARN of the RAM role that you created in Step 1 for Source RAM Role ARN for Replication.

    6. Click Generate Policy.

    Method 2: Add by Syntax

    1. In the left-side navigation tree, choose Permission Control > Bucket Policy.

    2. On the Bucket Policy tab, click Add by Syntax and then click Edit.

    3. In the code editor, enter the following bucket policy.

      Important
      • If you configure a bucket policy by specifying policy statements to grant the RAM role the required permissions, the new bucket policy overwrites the existing bucket policy. Make sure that the new bucket policy contains the content of the existing bucket policy. Otherwise, the authorization of the existing bucket policy may fail.

      • Replace the custom role name with the name of the role that you created based on your business requirements. If the created role name contains uppercase letters, you need to convert them to lowercase letters. For example, if the created role name is AliyunOssDrsRole, you need to convert AliyunOssDrsRole to aliyunossdrsrole. In the following example, the name of the destination bucket is dest-bucket, the UID of the account to which the source bucket belongs is 137918634953xxxx, and the UID of the account to which the destination bucket belongs is 111933544165xxxx.

      {
         "Version":"1",
         "Statement":[
            {
              "Effect":"Allow",
              "Action":[
                  "oss:ReplicateList",
                  "oss:ReplicateGet",
                  "oss:ReplicatePut",
                  "oss:ReplicateDelete"			
               ],
              "Principal": [
                  "arn:sts::137918634953xxxx:assumed-role/aliyunossdrsrole/*"		 
      		 ],
               "Resource":[
                  "acs:oss:*:111933544165xxxx::dest-bucket",          	
                  "acs:oss:*:111933544165xxxx::dest-bucket/*"
               ]
            }
         ]
      }
    4. Click Save. In the message that appears, click OK.

  3. Create a CRR rule for the source bucket by using Account A.

    1. Log on to the OSS console.

    2. In the left-side navigation pane, click Buckets. On the Buckets page, click the name of the source bucket.

    3. In the left-side navigation tree, choose Data Management > CRR.

    4. On the CRR tab, click CRR.

    5. In the CRR panel, configure the parameters. The following table describes the parameters.

      Section

      Parameter

      Description

      Configure Destination Bucket

      Source Bucket

      The region and name of the source bucket are displayed.

      Destination Bucket

      Select Specify a bucket that belongs to another Alibaba Cloud account, select a region from the Region drop-down list, and then enter the name of the destination bucket.

      Configure Replication Policy

      Objects to Replicate

      Select the objects that you want to replicate to the destination bucket. Valid values:

      • All Objects in Source Bucket: OSS replicates all objects from the source bucket to the destination bucket.

      • Objects with Specified Prefix: OSS replicates the objects whose names contain a specific prefix from the source bucket to the destination bucket. You can specify up to 10 prefixes.

      Replication Policy

      Configure the data replication mode. Valid values:

      • Add/Change: OSS replicates only object creation and update operations from the source bucket to the destination bucket.

      • Add/Delete/Change: OSS replicates object creation, update, and deletion operations from the source bucket to the destination bucket.

      If you perform multipart upload to upload an object to the source bucket, each uploaded part is replicated to the destination bucket. The complete object that is obtained by calling the CompleteMultipartUpload operation is also replicated to the destination bucket.

      For more information, see Use data replication with versioning.

      Replicate Historical Data

      Specify whether to replicate historical data (data that exists in the source bucket before you enable CRR) to the destination bucket.

      • Yes: Historical data is replicated to the destination bucket.

        Important

        When historical data is replicated, objects that are replicated from the source bucket may overwrite objects that have the same names in the destination bucket. To prevent data loss, we recommend that you enable versioning for the source and destination buckets.

      • No: OSS replicates only objects that are uploaded or updated after the CRR rule takes effect to the destination bucket.

      RAM Role Name

      Select the RAM role that you created in Step 1 from the drop-down list.

      Acceleration Type

      Transfer Acceleration is supported only when the source and destination buckets are respectively located in a region in the Chinese mainland and a region outside the Chinese mainland.

      If you enable transfer acceleration, you are charged transfer acceleration fees. For more information, see Transfer acceleration fees.

      RTC

      Note
      • RTC is available in the following regions: China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), and China (Shenzhen).

      • RTC is available in the following regions: US (Silicon Valley) and US (Virginia).

      After Replication Time Control (RTC) is enabled, OSS replicates most of the objects that you uploaded to OSS within a few seconds and replicates 99.99% of objects within 10 minutes. For more information, see RTC. You are charged when you enable RTC. For more information, see RTC traffic fees.

    6. Click OK. In the message that appears, click Enable.

      • After you configure a CRR rule, you cannot modify or delete the rule.

      • After you configure a CRR rule, the replication task starts in 3 to 5 minutes. You can view the replication progress on the CRR tab of the source bucket.

      • In CRR, data is asynchronously replicated. The period of time that is required to replicate data from the source bucket to the destination bucket varies based on the amount of data. The period of time may range from a few minutes to a few hours.

Use OSS SDKs

CRR across accounts is supported only by using OSS SDK for Java, OSS SDK for Python, and OSS SDK for Go.

Java

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.AddBucketReplicationRequest;

public class Demo {

    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // We recommend that you do not save access credentials in the project code. Otherwise, access credentials may be leaked. As a result, the security of all resources in your account is compromised. In this example, access credentials are obtained from environment variables. Before you run the sample code, make sure that the environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the source bucket. Example: src-bucket. 
        String bucketName = "src-bucket";
        // Specify the name of the destination bucket. The source and destination buckets must belong to different Alibaba Cloud accounts. 
        String targetBucketName = "dest-bucket";
        // Specify the region in which the destination bucket is located. The source and destination buckets must be located in different regions. 
        String targetBucketLocation = "oss-cn-shanghai";

        // Create an OSSClient instance. 
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            AddBucketReplicationRequest request = new AddBucketReplicationRequest(bucketName);
            request.setTargetBucketName(targetBucketName);
            request.setTargetBucketLocation(targetBucketLocation);
            // Specify whether to replicate historical data. By default, historical data is replicated. In this example, this parameter is set to false, which indicates that historical data is not replicated. 
            request.setEnableHistoricalObjectReplication(false);
            // Specify the name of the RAM role that you want OSS to use to replicate data. The role must have the permissions to perform CRR on the source bucket and receive replicated objects in the destination bucket. 
            request.setSyncRole("yourRole");           
            //List prefixes = new ArrayList();
            //prefixes.add("image/");
            //prefixes.add("video");
            //prefixes.add("a");
            //prefixes.add("A");
            // Specify the prefixes that are contained in the names of the objects that you want to replicate. After you specify the prefixes, only objects whose names contain one of the prefixes are replicated to the destination bucket. 
            //request.setObjectPrefixList(prefixes);
            //List actions = new ArrayList();
            //actions.add(AddBucketReplicationRequest.ReplicationAction.ALL);
            // Specify the operations that you want to replicate to the destination bucket. The default value is ALL. This indicates that all operations performed on objects in the source bucket are replicated to the destination bucket. 
            //request.setReplicationActionList(actions);
            ossClient.addBucketReplication(request);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}        

Python

# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
from oss2.models import ReplicationRule
# Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
auth = oss2.ProviderAuth(EnvironmentVariableCredentialsProvider())
# Specify the endpoint of the region in which the source bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. 
# Specify the name of the source bucket. Example: src-bucket. 
bucket = oss2.Bucket(auth, 'https://oss-cn-hangzhou.aliyuncs.com', 'src-bucket')
replica_config = ReplicationRule(
    # Specify the name of the destination bucket. The source and destination buckets must belong to different Alibaba Cloud accounts. 
    target_bucket_name='dest-bucket',
    # Specify the region in which the destination bucket is located. The source and destination buckets must be located in different regions. 
    target_bucket_location='oss-cn-shanghai',
    # Specify the name of the RAM role that you want OSS to use to replicate data. The role must have the permissions to perform CRR on the source bucket and receive replicated objects in the destination bucket. 
    sync_role_name='roleNameTest',
)

# Specify the prefixes that are contained in the names of the objects that you want to replicate. After you specify the prefixes, only objects whose names contain one of the prefixes are replicated to the destination bucket. 
# prefix_list = ['prefix1', 'prefix2']
# Specify the data replication rule. 
# replica_config = ReplicationRule(
     # prefix_list=prefix_list,
     # Specify the operations that you want to replicate to the destination bucket. The default value is ALL. This indicates that all operations performed on objects in the source bucket are replicated to the destination bucket. 
     # action_list=[ReplicationRule.ALL],
     # Specify the name of the destination bucket. The source and destination buckets must belong to different Alibaba Cloud accounts. 
     # target_bucket_name='dest-bucket',
     # Specify the region in which the destination bucket is located. The source and destination buckets must be located in different regions. 
     # target_bucket_location='yourTargetBucketLocation',
     # Specify whether to replicate historical data. By default, historical data is replicated. In this example, this parameter is set to False, which indicates that historical data is not replicated. 
     # is_enable_historical_object_replication=False,
     # Specify the link that you want to use to transfer data during data replication. 
     # target_transfer_type='oss_acc',    
  #)

# Enable data replication. 
bucket.put_bucket_replication(replica_config)

Go

package main

import (
    "encoding/xml"
    "fmt"
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
    "os"
)

func HandleError(err error) {
    fmt.Println("Error:", err)
    os.Exit(-1)
}

// Enable data replication. 
func main() {
    // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
    provider, err := oss.NewEnvironmentVariableCredentialsProvider()
    if err != nil {
    fmt.Println("Error:", err)
    os.Exit(-1)
    }
    // Create an OSSClient instance. 
    // Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint. 
    client, err := oss.New("yourEndpoint", "", "", oss.SetCredentialsProvider(&provider))
    if err != nil {
    fmt.Println("Error:", err)
    os.Exit(-1)
    }
    // Specify the name of the source bucket. 
    srcbucketName := "yourSrcBucket"
    // Specify the name of the destination bucket. The source and destination buckets must belong to different Alibaba Cloud accounts. 
    destBucketName := "yourDestBucket"
    // Specify the prefix_1 and prefix_2 prefixes that are contained in the names of the objects that you want to replicate. After you specify the prefixes, only objects whose names contain one of the prefixes are replicated to the destination bucket. 
    // To replicate all objects from the source bucket to the destination bucket, do not specify prefixes. 
    prefix1 := "prefix_1"
    prefix2 := "prefix_2"    
    prefixSet := oss.ReplicationRulePrefix{Prefix: []*string{&prefix1, &prefix2}}
    // Enable the RTC feature. 
    enabled := "enabled"
    reqReplication := oss.PutBucketReplication{
    Rule: []oss.ReplicationRule{
    {
    PrefixSet: &prefixSet,
    // Specify the operations that you want to replicate to the destination bucket. The default value is ALL. This indicates that all operations performed on objects in the source bucket are replicated to the destination bucket. 
    Action: "ALL",
    RTC:    &enabled,
    Destination: &oss.ReplicationRuleDestination{
    Bucket: destBucketName,
    // Specify the region in which the destination bucket is located. The source and destination buckets must be located in different regions.     
    Location: "oss-cn-hangzhou",
    // Specify the link that you want to use to transfer data during data replication. In this example, this parameter is set to oss_acc, which indicates that the link used for transfer acceleration is used. 
    TransferType: "oss_acc",
    },
    // Specify whether to replicate historical data. By default, historical data is replicated. In this example, this parameter is set to disabled, which indicates that historical data is not replicated. 
    HistoricalObjectReplication: "disabled",
    // Specify the name of the RAM role that you want OSS to use to replicate data. The role must have the permissions to perform CRR on the source bucket and receive replicated objects in the destination bucket. 
    SyncRole:                    "yourRole",    
    },
    },
    }

    xmlBody, err := xml.Marshal(reqReplication)
    if err != nil {
    HandleError(err)
    }
    err = client.PutBucketReplication(srcbucketName, string(xmlBody))

    if err != nil {
    HandleError(err)
    }

    fmt.Println("Put Bucket Replication Success!")
}

Use ossutil

For more information about how to use ossutil to perform CRR across accounts, see replication.

Use the OSS API

If your business requires a high level of customization, you can directly call the OSS API. To directly call an API, you must include the signature calculation in your code. For more information, see PutBucketReplication.

References