White paper: Best Practices for Migrating Oracle Databases to AWS EC2 instances
AWS documentation highlights several different methods for migrating Oracle database data to AWS. In addition, AWS published a white paper titled Strategies for Migrating Oracle Databases to AWS last updated August 2018. The solutions that AWS offers fail to address lift-and-shift scenarios for large databases requiring near-zero downtime when switching over from on-premises to AWS.
In this paper, we describe the steps we took for our customer using Oracle Data Guard to perform the synchronization needed for near-zero downtime between their on-premises database and the new Oracle database running on a new EC2 based primary replica.
The diagram below shows the resulting architecture with a secondary replica in a different availability zone and another replica in a different region for high availability.
By analyzing the performance data of the on-premises Oracle database using a combination of Oracle’s Automatic Workload Repository and the DB Best DBMSys Platform, we were able to reduce the Oracle core licensing count from 18 cores to 15 cores by using the new EC2 Nitro instances using EBS optimized volumes managed by Oracle’s Automatic Storage Management (ASM).