# Migrating data from an RDS for MySQL DB instance to an Amazon Aurora MySQL DB cluster Migrating from a MySQL DB instance to Aurora MySQL You can migrate (copy) data to an Amazon Aurora MySQL DB cluster from an RDS for MySQL DB instance. **Topics** + [ # Migrating an RDS for MySQL snapshot to Aurora ](AuroraMySQL.Migrating.RDSMySQL.Snapshot.md) + [ # Migrating data from an RDS for MySQL DB instance to an Amazon Aurora MySQL DB cluster by using an Aurora read replica ](AuroraMySQL.Migrating.RDSMySQL.Replica.md) **Note** Because Amazon Aurora MySQL is compatible with MySQL, you can migrate data from your MySQL database by setting up replication between your MySQL database and an Amazon Aurora MySQL DB cluster. For more information, see [Replication with Amazon Aurora](Aurora.Replication.md). # Migrating an RDS for MySQL snapshot to Aurora You can migrate a DB snapshot of an RDS for MySQL DB instance to create an Aurora MySQL DB cluster. The new Aurora MySQL DB cluster is populated with the data from the original RDS for MySQL DB instance. The DB snapshot must have been made from an Amazon RDS DB instance running a MySQL version that's compatible with Aurora MySQL. You can migrate either a manual or automated DB snapshot. After the DB cluster is created, you can then create optional Aurora Replicas. **Note** You can also migrate an RDS for MySQL DB instance to an Aurora MySQL DB cluster by creating an Aurora read replica of your source RDS for MySQL DB instance. For more information, see [Migrating data from an RDS for MySQL DB instance to an Amazon Aurora MySQL DB cluster by using an Aurora read replica](AuroraMySQL.Migrating.RDSMySQL.Replica.md). You can't migrate to Aurora MySQL version 3.05 and higher from some older MySQL 8.0 versions, including 8.0.11, 8.0.13, and 8.0.15. We recommend that you upgrade to MySQL version 8.0.28 before migrating. The general steps you must take are as follows: 1. Determine the amount of space to provision for your Aurora MySQL DB cluster. For more information, see [How much space do I need?](#AuroraMySQL.Migrating.RDSMySQL.Space) 1. Use the console to create the snapshot in the AWS Region where the Amazon RDS MySQL instance is located. For information about creating a DB snapshot, see [Creating a DB snapshot](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_CreateSnapshot.html). 1. If the DB snapshot is not in the same AWS Region as your DB cluster, use the Amazon RDS console to copy the DB snapshot to that AWS Region. For information about copying a DB snapshot, see [Copying a DB snapshot](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_CopySnapshot.html). 1. Use the console to migrate the DB snapshot and create an Aurora MySQL DB cluster with the same databases as the original MySQL DB instance. **Warning** Amazon RDS limits each AWS account to one snapshot copy into each AWS Region at a time. ## How much space do I need? When you migrate a snapshot of a MySQL DB instance into an Aurora MySQL DB cluster, Aurora uses an Amazon Elastic Block Store (Amazon EBS) volume to format the data from the snapshot before migrating it. In some cases, additional space is needed to format the data for migration. Tables that are not MyISAM tables and are not compressed can be up to 16 TB in size. If you have MyISAM tables, then Aurora must use additional space in the volume to convert the tables to be compatible with Aurora MySQL. If you have compressed tables, then Aurora must use additional space in the volume to expand these tables before storing them on the Aurora cluster volume. Because of this additional space requirement, you should ensure that none of the MyISAM and compressed tables being migrated from your MySQL DB instance exceeds 8 TB in size. ## Reducing the amount of space required to migrate data into Amazon Aurora MySQL You might want to modify your database schema prior to migrating it into Amazon Aurora. Such modification can be helpful in the following cases: + You want to speed up the migration process. + You are unsure of how much space you need to provision. + You have attempted to migrate your data and the migration has failed due to a lack of provisioned space. You can make the following changes to improve the process of migrating a database into Amazon Aurora. **Important** Be sure to perform these updates on a new DB instance restored from a snapshot of a production database, rather than on a production instance. You can then migrate the data from the snapshot of your new DB instance into your Aurora DB cluster to avoid any service interruptions on your production database. | Table type | Limitation or guideline | | --- | --- | | MyISAM tables | Aurora MySQL supports InnoDB tables only. If you have MyISAM tables in your database, then those tables must be converted before being migrated into Aurora MySQL. The conversion process requires additional space for the MyISAM to InnoDB conversion during the migration procedure. To reduce your chances of running out of space or to speed up the migration process, convert all of your MyISAM tables to InnoDB tables before migrating them. The size of the resulting InnoDB table is equivalent to the size required by Aurora MySQL for that table. To convert a MyISAM table to InnoDB, run the following command: `alter table . engine=innodb, algorithm=copy;` | | Compressed tables | Aurora MySQL doesn't support compressed tables (that is, tables created with `ROW_FORMAT=COMPRESSED`). To reduce your chances of running out of space or to speed up the migration process, expand your compressed tables by setting `ROW_FORMAT` to `DEFAULT`, `COMPACT`, `DYNAMIC`, or `REDUNDANT`. For more information, see [InnoDB row formats](https://dev.mysql.com/doc/refman/8.0/en/innodb-row-format.html) in the MySQL documentation. | You can use the following SQL script on your existing MySQL DB instance to list the tables in your database that are MyISAM tables or compressed tables. ``` -- This script examines a MySQL database for conditions that block -- migrating the database into Amazon Aurora. -- It needs to be run from an account that has read permission for the -- INFORMATION_SCHEMA database. -- Verify that this is a supported version of MySQL. select msg as `==> Checking current version of MySQL.` from ( select 'This script should be run on MySQL version 5.6 or higher. ' + 'Earlier versions are not supported.' as msg, cast(substring_index(version(), '.', 1) as unsigned) * 100 + cast(substring_index(substring_index(version(), '.', 2), '.', -1) as unsigned) as major_minor ) as T where major_minor <> 506; -- List MyISAM and compressed tables. Include the table size. select concat(TABLE_SCHEMA, '.', TABLE_NAME) as `==> MyISAM or Compressed Tables`, round(((data_length + index_length) / 1024 / 1024), 2) "Approx size (MB)" from INFORMATION_SCHEMA.TABLES where ENGINE <> 'InnoDB' and ( -- User tables TABLE_SCHEMA not in ('mysql', 'performance_schema', 'information_schema') or -- Non-standard system tables ( TABLE_SCHEMA = 'mysql' and TABLE_NAME not in ( 'columns_priv', 'db', 'event', 'func', 'general_log', 'help_category', 'help_keyword', 'help_relation', 'help_topic', 'host', 'ndb_binlog_index', 'plugin', 'proc', 'procs_priv', 'proxies_priv', 'servers', 'slow_log', 'tables_priv', 'time_zone', 'time_zone_leap_second', 'time_zone_name', 'time_zone_transition', 'time_zone_transition_type', 'user' ) ) ) or ( -- Compressed tables ROW_FORMAT = 'Compressed' ); ``` The script produces output similar to the output in the following example. The example shows two tables that must be converted from MyISAM to InnoDB. The output also includes the approximate size of each table in megabytes (MB). ``` +---------------------------------+------------------+ | ==> MyISAM or Compressed Tables | Approx size (MB) | +---------------------------------+------------------+ | test.name_table | 2102.25 | | test.my_table | 65.25 | +---------------------------------+------------------+ 2 rows in set (0.01 sec) ``` ## Migrating an RDS for MySQL DB snapshot to an Aurora MySQL DB cluster Migrating a DB snapshot to a DB cluster You can migrate a DB snapshot of an RDS for MySQL DB instance to create an Aurora MySQL DB cluster using the AWS Management Console or the AWS CLI. The new Aurora MySQL DB cluster is populated with the data from the original RDS for MySQL DB instance. For information about creating a DB snapshot, see [Creating a DB snapshot](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_CreateSnapshot.html). If the DB snapshot is not in the AWS Region where you want to locate your data, copy the DB snapshot to that AWS Region. For information about copying a DB snapshot, see [Copying a DB snapshot](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_CopySnapshot.html). ### Console When you migrate the DB snapshot by using the AWS Management Console, the console takes the actions necessary to create only the DB cluster. You can also choose for your new Aurora MySQL DB cluster to be encrypted at rest using an AWS KMS key. **To migrate a MySQL DB snapshot by using the AWS Management Console** 1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/). 1. Either start the migration from the MySQL DB instance or from the snapshot: To start the migration from the DB instance: 1. In the navigation pane, choose **Databases**, and then select the MySQL DB instance. 1. For **Actions**, choose **Migrate latest snapshot**. To start the migration from the snapshot: 1. Choose **Snapshots**. 1. On the **Snapshots** page, choose the snapshot that you want to migrate into an Aurora MySQL DB cluster. 1. Choose **Snapshot Actions**, and then choose **Migrate Snapshot**. The **Migrate Database** page appears. 1. Set the following values on the **Migrate Database** page: + **Migrate to DB Engine**: Select `aurora`. + **DB Engine Version**: Select the DB engine version for the Aurora MySQL DB cluster. + **DB Instance Class**: Select a DB instance class that has the required storage and capacity for your database, for example `db.r3.large`. Aurora cluster volumes automatically grow as the amount of data in your database increases. An Aurora cluster volume can grow to a maximum size of 128 tebibytes (TiB). So you only need to select a DB instance class that meets your current storage requirements. For more information, see [Overview of Amazon Aurora storage](Aurora.Overview.StorageReliability.md#Aurora.Overview.Storage). + **DB Instance Identifier**: Type a name for the DB cluster that is unique for your account in the AWS Region you selected. This identifier is used in the endpoint addresses for the instances in your DB cluster. You might choose to add some intelligence to the name, such as including the AWS Region and DB engine you selected, for example **aurora-cluster1**. The DB instance identifier has the following constraints: + It must contain from 1 to 63 alphanumeric characters or hyphens. + Its first character must be a letter. + It cannot end with a hyphen or contain two consecutive hyphens. + It must be unique for all DB instances per AWS account, per AWS Region. + **Virtual Private Cloud (VPC)**: If you have an existing VPC, then you can use that VPC with your Aurora MySQL DB cluster by selecting your VPC identifier, for example `vpc-a464d1c1`. For information on creating a VPC, see [Tutorial: Create a VPC for use with a DB cluster (IPv4 only)](CHAP_Tutorials.WebServerDB.CreateVPC.md). Otherwise, you can choose to have Aurora create a VPC for you by selecting **Create a new VPC**. + **DB subnet group**: If you have an existing subnet group, then you can use that subnet group with your Aurora MySQL DB cluster by selecting your subnet group identifier, for example `gs-subnet-group1`. Otherwise, you can choose to have Aurora create a subnet group for you by selecting **Create a new subnet group**. + **Public accessibility**: Select **No** to specify that instances in your DB cluster can only be accessed by resources inside of your VPC. Select **Yes** to specify that instances in your DB cluster can be accessed by resources on the public network. The default is **Yes**. **Note** Your production DB cluster might not need to be in a public subnet, because only your application servers require access to your DB cluster. If your DB cluster doesn't need to be in a public subnet, set **Publicly Accessible** to **No**. + **Availability Zone**: Select the Availability Zone to host the primary instance for your Aurora MySQL DB cluster. To have Aurora select an Availability Zone for you, select **No Preference**. + **Database Port**: Type the default port to be used when connecting to instances in the Aurora MySQL DB cluster. The default is `3306`. **Note** You might be behind a corporate firewall that doesn't allow access to default ports such as the MySQL default port, 3306. In this case, provide a port value that your corporate firewall allows. Remember that port value later when you connect to the Aurora MySQL DB cluster. + **Encryption**: Choose **Enable Encryption** for your new Aurora MySQL DB cluster to be encrypted at rest. If you choose **Enable Encryption**, you must choose a KMS key as the **AWS KMS key** value. If your DB snapshot isn't encrypted, specify an encryption key to have your DB cluster encrypted at rest. If your DB snapshot is encrypted, specify an encryption key to have your DB cluster encrypted at rest using the specified encryption key. You can specify the encryption key used by the DB snapshot or a different key. You can't create an unencrypted DB cluster from an encrypted DB snapshot. + **Auto Minor Version Upgrade**: This setting doesn't apply to Aurora MySQL DB clusters. For more information about engine updates for Aurora MySQL, see [Database engine updates for Amazon Aurora MySQLLong-term support (LTS) and beta releases for Amazon Aurora MySQL](AuroraMySQL.Updates.md). 1. Choose **Migrate** to migrate your DB snapshot. 1. Choose **Instances**, and then choose the arrow icon to show the DB cluster details and monitor the progress of the migration. On the details page, you can find the cluster endpoint used to connect to the primary instance of the DB cluster. For more information on connecting to an Aurora MySQL DB cluster, see [Connecting to an Amazon Aurora DB cluster](Aurora.Connecting.md). ### AWS CLI You can create an Aurora DB cluster from a DB snapshot of an RDS for MySQL DB instance by using the [https://docs.aws.amazon.com/cli/latest/reference/rds/restore-db-cluster-from-snapshot.html](https://docs.aws.amazon.com/cli/latest/reference/rds/restore-db-cluster-from-snapshot.html) command with the following parameters: + `--db-cluster-identifier` – The name of the DB cluster to create. + `--engine aurora-mysql` – For a MySQL 5.7–compatible or 8.0–compatible DB cluster. + `--kms-key-id` – The AWS KMS key to optionally encrypt the DB cluster with, depending on whether your DB snapshot is encrypted. + If your DB snapshot isn't encrypted, specify an encryption key to have your DB cluster encrypted at rest. Otherwise, your DB cluster isn't encrypted. + If your DB snapshot is encrypted, specify an encryption key to have your DB cluster encrypted at rest using the specified encryption key. Otherwise, your DB cluster is encrypted at rest using the encryption key for the DB snapshot. **Note** You can't create an unencrypted DB cluster from an encrypted DB snapshot. + `--snapshot-identifier` – The Amazon Resource Name (ARN) of the DB snapshot to migrate. For more information about Amazon RDS ARNs, see [Amazon Relational Database Service (Amazon RDS)](https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html#arn-syntax-rds). When you migrate the DB snapshot by using the `RestoreDBClusterFromSnapshot` command, the command creates both the DB cluster and the primary instance. In this example, you create a MySQL 5.7–compatible DB cluster named *mydbcluster* from a DB snapshot with an ARN set to *mydbsnapshotARN*. For Linux, macOS, or Unix: ``` aws rds restore-db-cluster-from-snapshot \ --db-cluster-identifier mydbcluster \ --snapshot-identifier mydbsnapshotARN \ --engine aurora-mysql ``` For Windows: ``` aws rds restore-db-cluster-from-snapshot ^ --db-cluster-identifier mydbcluster ^ --snapshot-identifier mydbsnapshotARN ^ --engine aurora-mysql ``` In this example, you create a MySQL 5.7–compatible DB cluster named *mydbcluster* from a DB snapshot with an ARN set to *mydbsnapshotARN*. For Linux, macOS, or Unix: ``` aws rds restore-db-cluster-from-snapshot \ --db-cluster-identifier mydbcluster \ --snapshot-identifier mydbsnapshotARN \ --engine aurora-mysql ``` For Windows: ``` aws rds restore-db-cluster-from-snapshot ^ --db-cluster-identifier mydbcluster ^ --snapshot-identifier mydbsnapshotARN ^ --engine aurora-mysql ``` # Migrating data from an RDS for MySQL DB instance to an Amazon Aurora MySQL DB cluster by using an Aurora read replica Migrating from RDS for MySQL to Aurora MySQL using a read replica Aurora uses the MySQL DB engines' binary log replication functionality to create a special type of DB cluster called an Aurora read replica for a source RDS for MySQL DB instance. Updates made to the source RDS for MySQL DB instance are asynchronously replicated to the Aurora read replica. We recommend using this functionality to migrate from a RDS for MySQL DB instance to an Aurora MySQL DB cluster by creating an Aurora read replica of your source RDS for MySQL DB instance. When the replica lag between the RDS for MySQL DB instance and the Aurora read replica is 0, you can direct your client applications to the Aurora read replica and then stop replication to make the Aurora read replica a standalone Aurora MySQL DB cluster. Be prepared for migration to take a while, roughly several hours per tebibyte (TiB) of data. For a list of regions where Aurora is available, see [Amazon Aurora](https://docs.aws.amazon.com/general/latest/gr/rande.html#aurora) in the *AWS General Reference*. When you create an Aurora read replica of an RDS for MySQL DB instance, Amazon RDS creates a DB snapshot of your source RDS for MySQL DB instance (private to Amazon RDS, and incurring no charges). Amazon RDS then migrates the data from the DB snapshot to the Aurora read replica. After the data from the DB snapshot has been migrated to the new Aurora MySQL DB cluster, Amazon RDS starts replication between your RDS for MySQL DB instance and the Aurora MySQL DB cluster. If your RDS for MySQL DB instance contains tables that use storage engines other than InnoDB, or that use compressed row format, you can speed up the process of creating an Aurora read replica by altering those tables to use the InnoDB storage engine and dynamic row format before you create your Aurora read replica. For more information about the process of copying a MySQL DB snapshot to an Aurora MySQL DB cluster, see [Migrating data from an RDS for MySQL DB instance to an Amazon Aurora MySQL DB cluster](AuroraMySQL.Migrating.RDSMySQL.md). You can have only one Aurora read replica for an RDS for MySQL DB instance. **Note** Replication issues can arise due to feature differences between Aurora MySQL and the MySQL database engine version of your RDS for MySQL DB instance that is the replication primary. If you encounter an error, you can find help in the [Amazon RDS community forum](https://forums.aws.amazon.com/forum.jspa?forumID=60) or by contacting AWS Support. You can't create an Aurora read replica if your RDS for MySQL DB instance is already the source for a cross-Region read replica. You can't migrate to Aurora MySQL version 3.05 and higher from some older RDS for MySQL 8.0 versions, including 8.0.11, 8.0.13, and 8.0.15. We recommend that you upgrade to RDS for MySQL version 8.0.28 before migrating. For more information on MySQL read replicas, see [ Working with read replicas of MariaDB, MySQL, and PostgreSQL DB instances](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html). ## Creating an Aurora read replica You can create an Aurora read replica for an RDS for MySQL DB instance by using the console, the AWS CLI, or the RDS API. ### Console **To create an Aurora read replica from a source RDS for MySQL DB instance** 1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/). 1. In the navigation pane, choose **Databases**. 1. Choose the MySQL DB instance that you want to use as the source for your Aurora read replica. 1. For **Actions**, choose **Create Aurora read replica**. 1. Choose the DB cluster specifications you want to use for the Aurora read replica, as described in the following table. [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Migrating.RDSMySQL.Replica.html) 1. Choose **Create read replica**. ### AWS CLI To create an Aurora read replica from a source RDS for MySQL DB instance, use the [https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-cluster.html](https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-cluster.html) and [https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html](https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html) AWS CLI commands to create a new Aurora MySQL DB cluster. When you call the `create-db-cluster` command, include the `--replication-source-identifier` parameter to identify the Amazon Resource Name (ARN) for the source MySQL DB instance. For more information about Amazon RDS ARNs, see [Amazon Relational Database Service (Amazon RDS)](https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html#arn-syntax-rds). Don't specify the master username, master password, or database name as the Aurora read replica uses the same master username, master password, and database name as the source MySQL DB instance. For Linux, macOS, or Unix: ``` aws rds create-db-cluster --db-cluster-identifier sample-replica-cluster --engine aurora \ --db-subnet-group-name mysubnetgroup --vpc-security-group-ids sg-c7e5b0d2 \ --replication-source-identifier arn:aws:rds:us-west-2:123456789012:db:primary-mysql-instance ``` For Windows: ``` aws rds create-db-cluster --db-cluster-identifier sample-replica-cluster --engine aurora ^ --db-subnet-group-name mysubnetgroup --vpc-security-group-ids sg-c7e5b0d2 ^ --replication-source-identifier arn:aws:rds:us-west-2:123456789012:db:primary-mysql-instance ``` If you use the console to create an Aurora read replica, then Aurora automatically creates the primary instance for your DB cluster Aurora read replica. If you use the AWS CLI to create an Aurora read replica, you must explicitly create the primary instance for your DB cluster. The primary instance is the first instance that is created in a DB cluster. You can create a primary instance for your DB cluster by using the [https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html](https://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html) AWS CLI command with the following parameters. + `--db-cluster-identifier` The name of your DB cluster. + `--db-instance-class` The name of the DB instance class to use for your primary instance. + `--db-instance-identifier` The name of your primary instance. + `--engine aurora` In this example, you create a primary instance named *myreadreplicainstance* for the DB cluster named *myreadreplicacluster*, using the DB instance class specified in *myinstanceclass*. **Example** For Linux, macOS, or Unix: ``` aws rds create-db-instance \ --db-cluster-identifier myreadreplicacluster \ --db-instance-class myinstanceclass \ --db-instance-identifier myreadreplicainstance \ --engine aurora ``` For Windows: ``` aws rds create-db-instance ^ --db-cluster-identifier myreadreplicacluster ^ --db-instance-class myinstanceclass ^ --db-instance-identifier myreadreplicainstance ^ --engine aurora ``` ### RDS API To create an Aurora read replica from a source RDS for MySQL DB instance, use the [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBCluster.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBCluster.html) and [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html) Amazon RDS API commands to create a new Aurora DB cluster and primary instance. Do not specify the master username, master password, or database name as the Aurora read replica uses the same master username, master password, and database name as the source RDS for MySQL DB instance. You can create a new Aurora DB cluster for an Aurora read replica from a source RDS for MySQL DB instance by using the [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBCluster.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBCluster.html) Amazon RDS API command with the following parameters: + `DBClusterIdentifier` The name of the DB cluster to create. + `DBSubnetGroupName` The name of the DB subnet group to associate with this DB cluster. + `Engine=aurora` + `KmsKeyId` The AWS KMS key to optionally encrypt the DB cluster with, depending on whether your MySQL DB instance is encrypted. + If your MySQL DB instance isn't encrypted, specify an encryption key to have your DB cluster encrypted at rest. Otherwise, your DB cluster is encrypted at rest using the default encryption key for your account. + If your MySQL DB instance is encrypted, specify an encryption key to have your DB cluster encrypted at rest using the specified encryption key. Otherwise, your DB cluster is encrypted at rest using the encryption key for the MySQL DB instance. **Note** You can't create an unencrypted DB cluster from an encrypted MySQL DB instance. + `ReplicationSourceIdentifier` The Amazon Resource Name (ARN) for the source MySQL DB instance. For more information about Amazon RDS ARNs, see [Amazon Relational Database Service (Amazon RDS)](https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html#arn-syntax-rds). + `VpcSecurityGroupIds` The list of EC2 VPC security groups to associate with this DB cluster. In this example, you create a DB cluster named *myreadreplicacluster* from a source MySQL DB instance with an ARN set to *mysqlprimaryARN*, associated with a DB subnet group named *mysubnetgroup* and a VPC security group named *mysecuritygroup*. **Example** ``` https://rds.us-east-1.amazonaws.com/ ?Action=CreateDBCluster &DBClusterIdentifier=myreadreplicacluster &DBSubnetGroupName=mysubnetgroup &Engine=aurora &ReplicationSourceIdentifier=mysqlprimaryARN &SignatureMethod=HmacSHA256 &SignatureVersion=4 &Version=2014-10-31 &VpcSecurityGroupIds=mysecuritygroup &X-Amz-Algorithm=AWS4-HMAC-SHA256 &X-Amz-Credential=AKIADQKE4SARGYLE/20150927/us-east-1/rds/aws4_request &X-Amz-Date=20150927T164851Z &X-Amz-SignedHeaders=content-type;host;user-agent;x-amz-content-sha256;x-amz-date &X-Amz-Signature=6a8f4bd6a98f649c75ea04a6b3929ecc75ac09739588391cd7250f5280e716db ``` If you use the console to create an Aurora read replica, then Aurora automatically creates the primary instance for your DB cluster Aurora read replica. If you use the AWS CLI to create an Aurora read replica, you must explicitly create the primary instance for your DB cluster. The primary instance is the first instance that is created in a DB cluster. You can create a primary instance for your DB cluster by using the [https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html) Amazon RDS API command with the following parameters: + `DBClusterIdentifier` The name of your DB cluster. + `DBInstanceClass` The name of the DB instance class to use for your primary instance. + `DBInstanceIdentifier` The name of your primary instance. + `Engine=aurora` In this example, you create a primary instance named *myreadreplicainstance* for the DB cluster named *myreadreplicacluster*, using the DB instance class specified in *myinstanceclass*. **Example** ``` https://rds.us-east-1.amazonaws.com/ ?Action=CreateDBInstance &DBClusterIdentifier=myreadreplicacluster &DBInstanceClass=myinstanceclass &DBInstanceIdentifier=myreadreplicainstance &Engine=aurora &SignatureMethod=HmacSHA256 &SignatureVersion=4 &Version=2014-09-01 &X-Amz-Algorithm=AWS4-HMAC-SHA256 &X-Amz-Credential=AKIADQKE4SARGYLE/20140424/us-east-1/rds/aws4_request &X-Amz-Date=20140424T194844Z &X-Amz-SignedHeaders=content-type;host;user-agent;x-amz-content-sha256;x-amz-date &X-Amz-Signature=bee4aabc750bf7dad0cd9e22b952bd6089d91e2a16592c2293e532eeaab8bc77 ``` ## Viewing an Aurora read replica You can view the MySQL to Aurora MySQL replication relationships for your Aurora MySQL DB clusters by using the AWS Management Console or the AWS CLI. ### Console **To view the primary MySQL DB instance for an Aurora read replica** 1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/). 1. In the navigation pane, choose **Databases**. 1. Choose the DB cluster for the Aurora read replica to display its details. The primary MySQL DB instance information is in the **Replication source** field. ![\[View MySQL primary\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/images/aurora-repl6.png) ### AWS CLI To view the MySQL to Aurora MySQL replication relationships for your Aurora MySQL DB clusters by using the AWS CLI, use the [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusters.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusters.html) and [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-instances.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-instances.html) commands. To determine which MySQL DB instance is the primary, use the [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusters.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-clusters.html) and specify the cluster identifier of the Aurora read replica for the `--db-cluster-identifier` option. Refer to the `ReplicationSourceIdentifier` element in the output for the ARN of the DB instance that is the replication primary. To determine which DB cluster is the Aurora read replica, use the [https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-instances.html](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-instances.html) and specify the instance identifier of the MySQL DB instance for the `--db-instance-identifier` option. Refer to the `ReadReplicaDBClusterIdentifiers` element in the output for the DB cluster identifier of the Aurora read replica. **Example** For Linux, macOS, or Unix: ``` aws rds describe-db-clusters \ --db-cluster-identifier myreadreplicacluster ``` ``` aws rds describe-db-instances \ --db-instance-identifier mysqlprimary ``` For Windows: ``` aws rds describe-db-clusters ^ --db-cluster-identifier myreadreplicacluster ``` ``` aws rds describe-db-instances ^ --db-instance-identifier mysqlprimary ``` ## Promoting an Aurora read replica After migration completes, you can promote the Aurora read replica to a stand-alone DB cluster using the AWS Management Console or AWS CLI. Then you can direct your client applications to the endpoint for the Aurora read replica. For more information on the Aurora endpoints, see [Amazon Aurora endpoint connections](Aurora.Overview.Endpoints.md). Promotion should complete fairly quickly, and you can read from and write to the Aurora read replica during promotion. However, you can't delete the primary MySQL DB instance or unlink the DB Instance and the Aurora read replica during this time. Before you promote your Aurora read replica, stop any transactions from being written to the source MySQL DB instance, and then wait for the replica lag on the Aurora read replica to reach 0. You can view the replica lag for an Aurora read replica by calling the `SHOW SLAVE STATUS` (Aurora MySQL version 2) or `SHOW REPLICA STATUS` (Aurora MySQL version 3) command on your Aurora read replica. Check the **Seconds behind master** value. You can start writing to the Aurora read replica after write transactions to the primary have stopped and replica lag is 0. If you write to the Aurora read replica before this and you modify tables that are also being modified on the MySQL primary, you risk breaking replication to Aurora. If this happens, you must delete and recreate your Aurora read replica. ### Console **To promote an Aurora read replica to an Aurora DB cluster** 1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/). 1. In the navigation pane, choose **Databases**. 1. Choose the DB cluster for the Aurora read replica. 1. For **Actions**, choose **Promote**. 1. Choose **Promote read replica**. After you promote, confirm that the promotion has completed by using the following procedure. **To confirm that the Aurora read replica was promoted** 1. Sign in to the AWS Management Console and open the Amazon RDS console at [https://console.aws.amazon.com/rds/](https://console.aws.amazon.com/rds/). 1. In the navigation pane, choose **Events**. 1. On the **Events** page, verify that there is a `Promoted Read Replica cluster to a stand-alone database cluster` event for the cluster that you promoted. After promotion is complete, the primary MySQL DB instance and the Aurora read replica are unlinked, and you can safely delete the DB instance if you want. ### AWS CLI To promote an Aurora read replica to a stand-alone DB cluster, use the [https://docs.aws.amazon.com/cli/latest/reference/rds/promote-read-replica-db-cluster.html](https://docs.aws.amazon.com/cli/latest/reference/rds/promote-read-replica-db-cluster.html) AWS CLI command. **Example** For Linux, macOS, or Unix: ``` aws rds promote-read-replica-db-cluster \ --db-cluster-identifier myreadreplicacluster ``` For Windows: ``` aws rds promote-read-replica-db-cluster ^ --db-cluster-identifier myreadreplicacluster ```