Skip to main content

Glossary

Definitions of terms and concepts used throughout layline.io.

Core Concepts​

Project​

A Project is the top-level container for everything you build in layline.io. It contains all configured Assets, Workflows, Deployment Assets, and project-specific configurations. Projects are created and managed in the Configuration Center.

See also: Core Concepts

Asset​

An Asset is a reusable building block that captures a specific piece of configuration — a connection, data format, processing step, or service — independently of any particular Workflow. Assets can be shared across multiple Workflows within a Project and support inheritance.

See also: Core Concepts

Asset Class​

An Asset Class represents a category of functionality. layline.io includes the following Asset Classes:

Asset ClassPurpose
WorkflowsExecutable data flow definitions
FormatsData structure definitions
ConnectionsConnectivity to external systems
ServicesShared service definitions
SourcesRead data from external systems
SinksWrite data to external systems
Input ProcessorsEntry point processing for Workflows
Output ProcessorsExit point processing for Workflows
Flow ProcessorsTransform, route, enrich, filter data
ResourcesEnvironment variables, secrets, and configuration
ExtensionsCustom processing components

Asset Type​

An Asset Type is a specific implementation within an Asset Class. For example, the Format Asset Class includes ASN.1, Data Dictionary, Generic, HTTP, and XML types. Each Asset Class provides one or more Asset Types.

Workflow​

A Workflow is the core unit of execution in layline.io. It defines how data flows from a single Input Processor through a series of Flow Processors to one or more Output Processors. Each Workflow has exactly one Input Processor that drives execution.

See also: Core Concepts

Processor​

A Processor is a runtime instance of an Asset within a Workflow. Processors come in three types:

  • Input Processor — The single driver of a Workflow; reads from sources and initiates processing
  • Flow Processor — Transforms, routes, enriches, or filters data in the middle of a Workflow
  • Output Processor — Writes results to destinations at the end of a Workflow

Deployment​

A Deployment defines which Workflows, Environment Assets, and Secret Assets are deployed to a Reactive Cluster. Deploying sends the configuration to one Reactive Engine, which propagates it to all cluster members.

See also: Core Concepts

Data Dictionary​

The Data Dictionary is a unified schema built from all configured Format Assets in a Project. It represents the superset of all data structures, allowing data to flow through the system without intermediate mapping steps.

See also: Data Dictionary

System Components​

Configuration Server​

The Configuration Server is the central design-time component that:

  • Stores all Projects, Workflows, and Assets
  • Serves the web-based Configuration Center
  • Manages deployment state and versioning
  • Maintains a filesystem-based store of Project configurations

The Configuration Server does not process data — it is the authoritative source of "what should be running."

See also: Architecture Overview

Configuration Center​

The Configuration Center is the web-based UI served by the Configuration Server. It provides:

  • Project editor with visual workflow designer
  • Asset configuration interface
  • Deployment interface to push configurations to Reactive Engines
  • Operations dashboard for monitoring clusters and workflows

See also: Architecture Overview

Reactive Engine​

A Reactive Engine is the runtime component that executes Workflows. It:

  • Runs data pipelines designed in the Configuration Center
  • Manages connections to sources and sinks
  • Handles stream processing, backpressure, and flow control
  • Participates in clusters for distributed execution

Each Reactive Engine is an independent process that can run standalone or as part of a cluster.

See also: Architecture Overview

Reactive Cluster​

A Reactive Cluster (also called Cluster) is a logical grouping of one or more Reactive Engines that:

  • Shares workload across available engines
  • Provides resilience — if one engine fails, others pick up its work
  • Enables horizontal scaling by adding or removing engines dynamically

A single Reactive Engine running alone is technically a Reactive Cluster with one node.

See also: Architecture Overview

Node​

A Node is a host machine (physical or virtual) where a Reactive Engine runs. Nodes can be:

  • Your local development machine
  • A Docker container
  • A Kubernetes pod
  • A cloud VM instance

Configuration​

Configuration refers to the complete set of Assets, Workflows, and settings that define how data is processed. Configuration is created in the Configuration Center and deployed to Reactive Engines.

Operations Terminology​

Engine State​

Engine State is the live view of what is currently running on a Reactive Engine or Cluster. It shows active workflows, services, sources, sinks, and their current status. Engine State is accessed through the Operations tab in the Configuration Center.

See also: Engine State

Activation Digest​

An Activation Digest is a short hash (first 6 characters displayed, full value in tooltip) that identifies a specific deployment activation. It helps track which version of a configuration is running on a given engine.

Alarm​

An Alarm is a notification triggered by the system when something requires attention — such as a workflow failure, resource exhaustion, or configuration error. Alarms are managed in the Alarm Center.

See also: Alarm Center

Audit Trail​

The Audit Trail is a log of workflow executions, stream events, and system activities. It provides a historical record for debugging, compliance, and performance analysis.

See also: Audit Trail

Stream Monitor​

The Stream Monitor is an operations view that provides real-time visibility into data flowing through the system, including throughput metrics and processing latency.

See also: Stream Monitor

Scheduler​

The Scheduler is a component that manages time-based execution of workflows, allowing scheduled starts, stops, and recurring processing windows.

See also: Scheduler

Asset Relationships​

Asset Inheritance​

Asset Inheritance allows a child Asset to derive from a parent Asset of the same Class and Type. The child inherits all parent settings and can override individual parameters. This enables building portfolios of reusable, slightly varied Asset configurations.

Asset Dependency​

An Asset Dependency exists when one Asset requires another to function. For example:

  • An Input Processor typically requires a Format Asset and a Source Asset
  • A Sink may require a Connection Asset
  • A Service may require Resource Assets (Environment or Secret)

Dependencies must be resolved for an Asset to operate correctly.

Hidden Asset​

A Hidden Asset is an Asset created automatically when you add a Processor directly in a Workflow without first creating a standalone Asset. Hidden Assets are single-use and embedded within the Workflow, while regular Assets are reusable across Workflows.

Environment Asset​

An Environment Asset defines environment variables that can be referenced in other Assets using ${VAR_NAME} syntax. Environment Assets enable environment-agnostic configuration — the same Assets can be deployed to different environments with different variable values.

Secret Asset​

A Secret Asset stores sensitive configuration values (passwords, API keys, certificates) separately from regular configuration. Secret values are masked in the UI and can be referenced by name in other Assets.

Data Processing Terms​

Source​

A Source is an Asset that defines where data enters the system — such as a file directory, message queue, HTTP endpoint, or database. Sources are used by Input Processors to read data.

See also: Sources

Sink​

A Sink is an Asset that defines where data exits the system — such as a file, database, message queue, or API endpoint. Sinks are used by Output Processors to write results.

See also: Sinks

Format​

A Format is an Asset that defines the structure of data — such as XML, JSON, ASN.1, or custom schemas. Formats enable layline.io to parse and validate incoming data and serialize outgoing data.

See also: Formats

Connection​

A Connection is an Asset that defines connectivity parameters to external systems — such as AWS credentials, Kafka brokers, or FTP servers. Connections are reusable across multiple Sources, Sinks, or Services.

See also: Connections

Service​

A Service is an Asset that provides shared functionality — such as database access, HTTP clients, message queues, or AI/ML inference. Services can be called from Processors using the JavaScript or Python API.

See also: Services

Message / Event​

In layline.io, Message and Event are often used interchangeably to refer to a unit of data flowing through the system. A Message has a structure defined by the Data Dictionary and may contain payload data, headers, and metadata.

Dead Letter​

A Dead Letter is a message that failed processing and was routed to a special error handling path. Dead letter routing can be configured on Processors to handle failures gracefully.

Backpressure​

Backpressure is a flow control mechanism where downstream components signal upstream components to slow down when they cannot keep up with the data rate. layline.io handles backpressure automatically in stream processing.

UI Terminology​

Project Tab​

The Project Tab is the section of the Configuration Center where you build and manage Workflows and Assets. It provides the visual workflow designer and asset configuration interface.

Operations Tab​

The Operations Tab is the section of the Configuration Center where you monitor and control running deployments. It provides views for cluster status, engine state, alarms, and audit trails.

Shelf Tab​

The Shelf Tab is the section of the Configuration Center that serves as a reusable Asset library. Assets published to the Shelf can be shared across Projects.

See also: Shelf

Settings Tab​

The Settings Tab is the section of the Configuration Center for administrative functions — managing users, roles, clusters, and application settings.

See also: Settings

Asset Viewer​

The Asset Viewer is the configuration panel where you define and edit Asset settings. Different Asset types have different viewer layouts based on their configuration requirements.

Workflow Viewer​

The Workflow Viewer is the visual canvas where you design Workflows by connecting Processors. It shows the data flow from Input through Flow to Output Processors.

Deployment Terms​

Deployment Asset​

A Deployment Asset is configuration that controls how Workflows are deployed and executed, including:

  • Engine Deployment — defines cluster membership and resource allocation
  • Scheduler — manages time-based execution
  • Tag — labels for organizing and selecting Assets

Engine Deployment​

An Engine Deployment is a Deployment Asset that defines which Workflows and Assets are deployed to which Reactive Engines, along with runtime parameters like parallelism and resource limits.

See also: Engine Deployment

Activation​

An Activation is the process of applying a Deployment to a Reactive Cluster. When a Deployment is activated, the configuration is distributed to all engines in the cluster, and the specified Workflows begin executing.

Digest​

A Digest is a hash that uniquely identifies a specific version of a Deployment or Asset configuration. Digests enable tracking of configuration changes and ensure consistency across cluster nodes.

See Also​

Last updated on