Upgrading to 0.33.0

The org.occurrent.UpgradeToOccurrent_0_33 recipe makes the mechanical changes for you. Run it before editing anything by hand.

Two changes break compilation. CheckpointStorage, blocking and reactor both, gained a conditional write, so an implementation you wrote yourself has two more members to answer, the three-argument save and writeVersion. Code that only calls the storage keeps compiling, because the two-argument save stays as a default that delegates to the new one. The recipe stubs the two members on a Java implementation, each marked with a review comment, while a Kotlin implementation adds them by hand. And a saga timer’s name is now a TimerName rather than a String, so constructing SagaTimeout, StartTimeout, StartTimeoutAt or CancelTimeout from a string name, or reading timerName() into a String, stops compiling. The recipe rewrites every construction it can prove and marks the rest.

Five subscription-capability interfaces are also renamed. ReplayAwareSubscriptionModel becomes ReplayAwareSubscriptions and IntrospectableSubscriptionModel becomes IntrospectableSubscriptions, on both stacks, and the blocking DelegatingSubscriptionModel becomes SubscriptionModelWrapper together with its two methods. Their static lookup method goes from of to findIn. None of the five ever extended SubscriptionModel, which is the relationship the old names claimed. The recipe rewrites these too.

A few behavior changes affect already-running code, with no compiler error to point at them. A saga that declares a sealed event type now receives the concrete events stored under its permitted subtypes, which the saga DSL in 0.32.0 silently missed. Checkpoint writes are fenced whenever a competing-consumer strategy is configured, so a write from a node whose lease has moved to another node is refused instead of overwriting the new holder’s checkpoint, and a competing consumer that regains its lease resumes from the stored checkpoint instead of the position it had read before losing it. ManualStartSubscriptionModel and ReactorDurableSubscriptionModel now record a subscription’s first-run start position with a single conditional write, so two nodes registering the same subscription for the first time can no longer both write with the later one silently winning. And the deprecated join’s reaction now reads the same events a condition branch’s reaction reads, instead of everything the instance has kept.

See the upgrade guide for the full details and the steps the recipe cannot make for you.