For many organisations the rational response to Oracle's employee based Java subscription is to stop using Oracle Java and migrate to a free distribution. Amazon Corretto is one of the most widely adopted alternatives, a no cost, production ready build of OpenJDK with long term support from Amazon. This article sets out how to evaluate and execute a migration from Oracle Java to Amazon Corretto from the buyer side.
This article is a companion to our Java licensing pillar and supports our cloud migration advisory service.
Why Corretto Is a Credible Alternative
Amazon Corretto is a distribution of OpenJDK, the open source reference implementation that Oracle's own JDK is built from. Corretto is free to use in production, includes long term support and security updates, and is certified compatible with the Java standard. For the large majority of workloads, Corretto behaves identically to Oracle JDK because both derive from the same upstream source.
The credibility of Corretto rests on the fact that the underlying technology is the same. The differences between Oracle JDK and OpenJDK based distributions are narrow and well documented. Most applications run unchanged. The migration is therefore lower risk than its strategic importance might suggest, which is what makes it such an effective response to the Oracle Java subscription.
The Cost Case
The cost case for migration is usually decisive. Oracle's employee based Java subscription charges for the entire headcount. A migration to Corretto eliminates that cost entirely, replacing a per employee subscription with a free distribution. For an organisation of any size the saving is substantial and recurring.
The Java migration business case is one of the cleanest we see. The Oracle subscription cost is large, recurring, and tied to headcount. The Corretto alternative is free. The migration cost is a one time project expense. The payback is almost always inside the first year, often inside the first quarter.
The cost comparison should weigh the recurring Oracle subscription against the one time migration project cost plus any ongoing support arrangement the organisation chooses to put in place. Even where the organisation buys commercial support for its OpenJDK distribution, the cost is typically far below the Oracle employee subscription. The business case rarely fails.
The Inventory First Step
The migration begins with an inventory of every Oracle Java installation across the estate. Servers, desktops, embedded uses, and build pipelines all need to be identified. The inventory establishes the scope of the migration and, importantly, the scope of any historical Oracle exposure that needs to be resolved alongside the migration.
The inventory is also the foundation of the audit defence position. An organisation that knows exactly what it has deployed can both plan the migration and respond to any Oracle Java review. Our Java audit defense article covers how the inventory supports the defensive position.
The Compatibility Testing
While Corretto is highly compatible, responsible migration includes compatibility testing. The testing confirms that applications run correctly on Corretto, that performance is equivalent, and that any edge cases involving Oracle specific features are identified. Most applications pass without changes. The small minority that rely on Oracle specific commercial features need attention.
The testing should cover the production critical applications first, then the broader estate. The goal is to confirm equivalence and to surface any application that uses a feature unique to Oracle JDK, such as certain commercial monitoring features, which may need an alternative. The testing de risks the migration and builds confidence for the production cutover.
The Phased Cutover
The migration should proceed in phases rather than as a single switch. Non production environments migrate first, providing a low risk proving ground. Production environments follow once the non production migration is validated. The phased approach contains risk and allows the organisation to build operational confidence with Corretto before committing the production estate.
The phasing also allows the organisation to demonstrate progress to Oracle if a review is underway. An organisation actively migrating off Oracle Java is in a stronger negotiating position than one that has only contemplated it. The migration in progress is itself a negotiating asset. Our audit defense service covers how migration progress shapes the negotiation.
The Support Question
Corretto includes free long term support from Amazon, with security updates and bug fixes. For many organisations this is sufficient. Organisations with stricter support requirements can purchase commercial support for OpenJDK based distributions from several vendors. Either way the support cost is far below the Oracle subscription, and the organisation chooses its support level rather than paying for Oracle's by default.
The support decision should match the organisation's risk tolerance and regulatory requirements. A regulated organisation may want a commercial support contract. A less regulated organisation may rely on Amazon's free support. The flexibility to choose is itself a benefit of leaving the Oracle subscription. Our Oracle Java product page covers the broader landscape.
The Historical Exposure Cleanup
Migration eliminates the forward Oracle Java cost, but it does not automatically resolve any historical exposure. If the organisation used Oracle Java without a subscription in the past, Oracle may pursue a claim for that period. The migration should be paired with a resolution of the historical position so that the organisation closes the issue completely.
The historical claim is a negotiation, and the migration strengthens the customer's hand. An organisation that has removed Oracle Java and migrated to Corretto has eliminated the forward leverage Oracle would otherwise hold. The historical claim can then be settled on the customer's terms. Our Java SE Universal deal page covers the subscription framing and the contract term article covers the alternative of subscribing.
Where to Read Next
For audit defence see our Java audit defense article. For contract terms see our contract term article. For the broader Java strategy see our Java licensing pillar. The Oracle Java Negotiation Guide covers the full methodology.