Runtime Adapters

Runtime adapters execute downstream delivery work. They do not own correctness.

Built-in adapters:

runtime:
  adapter: inline

runtime:
  adapter: concurrent
  concurrency: 5
  preserve_order: true

Adapter contract:

runtime.process_many(work_items)
runtime.shutdown

The runtime registry wraps the selected adapter runtime in Mammoth::Runtimes::BatchingRuntime. That execution boundary accepts individual core work through process, owns runtime.batch_size accumulation, and submits full or final partial batches through the adapter's process_many method. Mammoth::Application coordinates flush and shutdown lifecycle calls but does not buffer or partition work itself.

The processor passed to a runtime is Mammoth::DeliveryProcessor. It implements CDC::Core::Processor and returns a CDC::Core::ProcessorResult for every work item. DeliveryWorker owns retry, delivered-ledger, and DLQ behavior. After a durable result, the processor reports completion to the shared contiguous progress coordinator; the coordinator alone advances checkpoints and upstream acknowledgements. A source-owned resolver supplies the durable position, keeping PostgreSQL transport LSNs out of generic runtime and CDC-core contracts.

Runtime inputs are exact CDC::Core::ChangeEvent or CDC::Core::TransactionEnvelope instances. Runtime adapters should not accept hashes or private objects that merely expose similar methods.

Both built-in runtimes accept a CDC::Core::Observer and emit canonical dispatch_started, dispatch_succeeded, dispatch_failed, and dispatch_skipped notifications. Mammoth::Application installs Mammoth::MetricsObserver by default. Custom runtime adapters should preserve the same processor-result and observer lifecycle contract.

Built-in registration:

Mammoth::Runtimes::Registry.register("inline", Mammoth::Runtimes::InlineAdapter)
Mammoth::Runtimes::Registry.register("concurrent", Mammoth::Runtimes::ConcurrentAdapter)

Unknown runtime adapter names fail with Mammoth::ConfigurationError.