Terminology

Essential Vuo concepts

Clarity in operations starts from terminology. Vuo uses a deliberately small vocabulary. This page explains the terms you will encounter most often.

Flow: A configured business data flow. A Flow defines what work Vuo should recognize or schedule, which processor should handle it, where outputs go, and what operational and business expectations apply.
Work Item: One durable unit of business work inside Vuo. A Work Item has an explicit lifecycle and remains visible through processing, retries, failures, acknowledgement, and completion.
Work Attempt: One execution attempt for a Work Item. A retry creates another Work Attempt for the same Work Item rather than creating new business work.
State: The durable lifecycle state of a Work Item, such as Pending, Processing, Retry Pending, Awaiting Acknowledgement, Completed, Failed, or Quarantined.
Phase: The more specific activity Vuo is currently performing inside a Work Item state, such as processor execution or delivery. Phases add detail without turning every internal activity into another Work Item state.
Processor: C# code that performs business-specific processing or transformation. Processors work through the Vuo SDK while Vuo owns orchestration, retries, artifact handling, delivery, and durable state.
Processor Step: A meaningful sub-step reported by processor code, such as “Validate input”, “Transform shipment”, or “HTTP delivery”. If processing fails, Vuo can show exactly which step was active.
Artifact: A file or other data artifact associated with processing. Examples include acquired source files, processor outputs, temporary delivery files, and final delivered files.
Source Occurrence: One physical occurrence of a source artifact. If a file disappears and a file later appears at the same path, Vuo can treat that as a new occurrence even if the filename is identical.
Endpoint: A configured external location or system used by a Flow, such as a filesystem directory, network share, SFTP location, or another supported integration endpoint.
Delivery: The controlled transfer of a verified processor output to its destination. Vuo treats delivery as a durable milestone rather than assuming that successful processing means successful delivery.
Acknowledgement: Evidence that something downstream happened after delivery. Depending on the Flow, this might be a response, a status change, or even the confirmed disappearance of a delivered file from an observable location.
Retry: A delayed new attempt to continue a failed Work Item. Vuo retries from known durable state rather than blindly recreating the original business work.
Lease: A time-limited claim that gives one Runtime temporary ownership of a Work Item. If the Runtime crashes or disappears, the lease expires and the work can be recovered safely.
Quarantine: A deliberate state for work that should not continue automatically, for example because an unsafe collision or serious data-integrity problem requires investigation.
Technical Health: Whether Vuo and its technical dependencies appear able to operate: Runtime availability, endpoint connectivity, storage capacity, processor availability, and similar conditions.
Business Health: Whether the business activity expected from a Flow is actually happening. A Flow can be technically healthy and still have Critical business health because an expected file, order, acknowledgement, or volume never appeared.
Expectation: A rule describing what should happen from the business point of view, such as minimum daily volume, first file by a certain time, maximum silence, or acknowledgement within a time limit.
Guard: A Vuo protection service that observes a resource or workload and responds predictably when conditions become unsafe. Examples include Flow Volume Guard and Storage Guard.
Processor Pool: A supervised execution boundary for custom processors. Processor Pools can limit concurrency, memory, CPU, execution time, and the effect a faulty custom processor can have on the rest of Vuo.
Processor Test Run: An isolated execution used to test a processor with an uploaded or preserved input artifact without changing the original Work Item or treating the test as normal production work.
Reliability Lab: Vuo's validation framework for deliberately introducing failures such as crashes, unavailable destinations, interrupted transfers, low storage, or processor faults and verifying that recovery behaves as designed.