Glossary

This glossary gives the fixed reader-facing meaning of the terms used throughout the V1 documentation.

Term	V1 meaning
deliverAt	Earliest instant at which a destination consumer may become eligible to receive a delayed message.
actionAt	Earliest instant at which Nereus Delay may start the destination action needed to satisfy deliverAt.
Trusted UTC interval	Bounded [earliestUtcNow, latestUtcNow] estimate used for fail-closed timing decisions.
Managed Delivery	Default mode with server-side Command, query, cancel, reschedule, quota, audit, and recovery boundaries.
AUTO_FAST	Explicit SDK permission to choose a prepared managed branch or a certified native Pulsar branch before I/O.
Delay Semantic Core	Shared zero-I/O preparation boundary used by both the Direct SDK and Delay Gateway.
Delay Gateway	Optional multi-language and centralized-governance entry around the same Semantic Core and guarded transports.
Command	Immutable request to Schedule, Cancel, Reschedule, or perform another registered operation.
Delay Shard	One source-partition ordering, ownership, RocksDB, checkpoint, and recovery unit.
Shard Log	Complete ordered stream of Client Commands and authenticated System Mutations for one Delay Shard.
Source Position	Ingress Broker position that orders Client Commands and System Mutations within one route partition.
Queued Command	Command durably accepted by the ingress Broker but not yet authoritatively applied by its Delay Shard.
Applied Command	Command whose authoritative outcome is durably recorded by the Delay Shard.
Delayed Message	Managed logical message created only after a Schedule Command is successfully applied.
Message Generation	Scheduling version of one Delayed Message; Reschedule creates a new generation so stale attempts cannot overwrite it.
Publish Admission	Durable transition to PUBLISHING that precedes producer I/O and forms the cancellation point of no return.
UNCERTAIN	Outcome where the system cannot prove whether a destination side effect became durable.
Destination Lane	Bounded group sharing destination, tenancy, and Ordering Domain characteristics for fairness, retry, and isolation.
Owner Lease	Oxia authority that, together with source assignment, permits one Worker to activate a Delay Shard.
Recovery Set	Bounded ordered set of published checkpoints from which recovery may choose.
Recovery Floor	Oldest checkpoint still permitted by the Recovery Set; resources needed by permitted checkpoints remain protected.
Uncertain Enqueue	Outcome where the client cannot prove whether the ingress Broker persisted the prepared command.

Avoid these substitutions

• Do not call a queued command a scheduled message.
• Do not call deliverAt publish time or exact consumer receive time.
• Do not call a timeout definitely-not-queued.
• Do not call UNCERTAIN definitely failed or safe to retry.
• Do not call a local uploaded checkpoint authoritative until it is published in the catalog.
• Do not treat a Lane as an ownership or recovery unit.