The things you must know before migration:-
1. Aurora can be placed only in three regions (us-east-1, us-west-2 and eu-west-1). So if you are planning to migrate other than these region, right now its not possible.
2. Before provisioning into Aurora make sure your db schema is compatible with mysql 5.6.
3. The migration can be done either from snapshot or from sql dump but the snapshot more than 6TB is not supported for migration. If your RDS storage is more than 6TB then you have to go with mysql import export migration.
4. Amazon Aurora only support Innodb engine and all MyISAM tables will be converted into Innodb during migration. If in existing database there are MyISAM tables make sure you have enough free storage space so the conversion take place.
5. The max supported size of Innodb table is 3TB and max supported size of MyISAM table is 1.5TB.
Note:- To fasten your migration process it is suggested first convert all MyISAM tables to Innodb and then start migration.
Amazon makes the migration process very simple, we can launch Aurora cluster with our RDS snapshot. First navigate to your RDS instance and from instance action click on “Migrate Database”.
At the time of migration it will check for existing snapshots and the latest snapshot considered for migration. If no snapshot found then the process ended with an error message.
In next window select your instance class, instance identifier and your network settings. We are migrating in default VPC and our Aurora cluster is publicly not accessible, change these values according to your scenario.
When you click on migrate, it will take approx 20-30 mins and this time may be increased depends upon your database size. As you seen the whole migration process is divided into four steps:-
a) It creates db cluster and then launches db instance with reader role. You will get instance identifier endpoint but the cluster endpoint will be available on the completion of final step.
b) Then it check for your database storage size, engine type and current mysql version.
c) In this section the data migration is performed and it converts all founded MyISAM tables to Innodb. it is the most time consuming process.
d) In final step once the cluster is available, instance role is changed to writer and you will get endpoint of cluster.
So we have migrated our RDS to Aurora and I hope it would be helpful in your migration.