Over my 17 years at Amazon, I have seen that my colleagues on the engineering team are never content to leave good-enough alone. They routinely re-evaluate every internal system to make sure that it is as scalable, efficient, performant, and secure as possible. When they find an avenue for improvement, they will use what they have learned to thoroughly modernize our architectures and implementations, often going so far as to rip apart existing systems and rebuild them from the ground up if necessary.
Today I would like to tell you about an internal database migration effort of this type that just wrapped up after several years of work. Over the years we realized that we were spending too much time managing and scaling thousands of legacy Oracle databases. Instead of focusing on high-value differentiated work, our database administrators (DBAs) spent a lot of time simply keeping the lights on while transaction rates climbed and the overall amount of stored data mounted. This included time spent dealing with complex & inefficient hardware provisioning, license management, and many other issues that are now best handled by modern, managed database services.
More than 100 teams in Amazon’s Consumer business participated in the migration effort. This includes well-known customer-facing brands and sites such as Alexa, Amazon Prime, Amazon Prime Video, Amazon Fresh, Kindle, Amazon Music, Audible, Shopbop, Twitch, and Zappos, as well as internal teams such as AdTech, Amazon Fulfillment Technology, Consumer Payments, Customer Returns, Catalog Systems, Deliver Experience, Digital Devices, External Payments, Finance, InfoSec, Marketplace, Ordering, and Retail Systems.
I am happy to report that this database migration effort is now complete. Amazon’s Consumer business just turned off its final Oracle database (some third-party applications are tightly bound to Oracle and were not migrated).
We migrated 75 petabytes of internal data stored in nearly 7,500 Oracle databases to multiple AWS database services including Amazon DynamoDB, Amazon Aurora, Amazon Relational Database Service (RDS), and Amazon Redshift. The migrations were accomplished with little or no downtime, and covered 100% of our proprietary systems. This includes complex purchasing, catalog management, order fulfillment, accounting, and video streaming workloads. We kept careful track of the costs and the performance, and realized the following results:
- Cost Reduction – We reduced our database costs by over 60% on top of the heavily discounted rate we negotiated based on our scale. Customers regularly report cost savings of 90% by switching from Oracle to AWS.
- Performance Improvements – Latency of our consumer-facing applications was reduced by 40%.
- Administrative Overhead – The switch to managed services reduced database admin overhead by 70%.
The migration gave each internal team the freedom to choose the purpose-built AWS database service that best fit their needs, and also gave them better control over their budget and their cost model. Low-latency services were migrated to DynamoDB and other highly scalable non-relational databases such as Amazon ElastiCache. Transactional relational workloads with high data consistency requirements were moved to Aurora and RDS; analytics workloads were migrated to Redshift, our cloud data warehouse.
We captured the shutdown of the final Oracle database, and had a quick celebration:
DBA Career Path
As I explained earlier, our DBAs once spent a lot of time managing and scaling our legacy Oracle databases. The migration freed up time that our DBAs now use to do an even better job of performance monitoring and query optimization, all with the goal of letting them deliver a better customer experience.
As part of the migration, we also worked to create a fresh career path for our Oracle DBAs, training them to become database migration specialists and advisors. This training includes education on AWS database technologies, cloud-based architecture, cloud security, OpEx-style cost management. They now work with both internal and external customers in an advisory role, where they have an opportunity to share their first-hand experience with large-scale migration of mission-critical databases.
Here are examples drawn from a few of the migrations:
Advertising – After the migration, this team was able to double their database fleet size (and their throughput) in minutes to accommodate peak traffic, courtesy of RDS. This scale-up effort would have taken months.
Buyer Fraud – This team moved 40 TB of data with just one hour of downtime, and realized the same or better performance at half the cost, powered by Amazon Aurora.
Financial Ledger – This team moved 120 TB of data, reduced latency by 40%, cut costs by 70%, and cut overhead by the same 70%, all powered by DynamoDB.
Wallet – This team migrated more than 10 billion records to DynamoDB, reducing latency by 50% and operational costs by 90% in the process. To learn more about this migration, read Amazon Wallet Scales Using Amazon DynamoDB.
My recent Prime Day 2019 post contains more examples of the extreme scale and performance that are possible with AWS.
If you are ready to migrate from Oracle (or another hand-managed legacy database) to one or more AWS database services, here are some resources to get you started:
AWS Migration Partners – Our slate of AWS Migration Partners have the experience, expertise, and tools to help you to understand, plan, and execute a database migration.
Migration Case Studies -Read How Amazon is Achieving Database Freedom Using AWS to learn more about this effort; read the Prime Video, Advertising, Items & Offers, Amazon Fulfillment, and Analytics case studies to learn more about the examples that I mentioned above.
AWS Professional Services – My colleagues at AWS Professional Services are ready to work alongside you to make your migration a success.
AWS Database Freedom – The AWS Database Freedom program is designed to help qualified customers migrate from traditional databases to cloud-native AWS databases.
AWS re:Invent Sessions – We are finalizing an extensive lineup of chalk talks and breakout sessions for AWS re:Invent that will focus on this migration effort, all led by the team members that planned and executed the migrations.