Concepts

Definitions of the key components and entities used in Fusioncat

This glossary defines the key terms you’ll encounter when working with Fusioncat. Use it as a quick reference to understand how schemas, messages, servers, resources, applications, projects, and workspaces fit together in logical order from the smallest building blocks to the containers that encapsulate them.

Overview

Overview Below is the list of glossary entries in the order they build on each other:

• Data schema
• Message
• Server
• Resources
• Application
• Consumer
• Producer
• Project
• Workspaces

Glossary

Data schema

A formal definition of the structure and data types within a payload. Fusioncat is designed to support three schema technologies—JSONSchema, Avro, and Protobuf—but currently only JSONSchemas are implemented.

Versioning.
Every change to a schema yields a new version, numbered sequentially starting at 1.

Message

A communication asset that carries data according to a particular schema version. Each message includes:

• A name and human-readable description.
• A reference to a specific schema and its version.
• Its own version number for tracking changes to the message metadata or payload structure.

Note: One schema can be used by multiple messages.

Server

Software or infrastructure that routes messages between producers and consumers. Examples include:

• Kafka brokers
• AMQP (RabbitMQ) servers
• MQTT brokers
• Simple setups using database tables or webhooks
• A server can host multiple resources.

Resources

Access points through which messages flow inside a server. Depending on server type, a resource might be one of:

• Kafka topic
• AMQP exchange or queue
• MQTT topic
• Database table
• Webhook endpoint

Each resource:

• Belongs to exactly one server.
• Has one of four modes: read, write, readwrite, or bind.
• The bind mode (AMQP-specific) links exchanges to queues.
• Uses a naming convention that fully qualifies its server, mode, and identifier, for example: async+amqp://mainrmq@read/queue/paymentqueue

Application

A computer program built on the Fusioncat stack that receives and/or sends messages.

• Consumer

  • The component responsible for receiving incoming messages.
  • Defined by a list of message-and-resource pairs from which it reads.

• Producer

  • The component responsible for sending messages.
  • Defined by a list of message-and-resource pairs to which it writes.

Project

A self-contained package that stores all schemas, messages, servers, resources, and applications.

• Everything in Fusioncat lives in a project.
• In future releases, projects will be able to reference artifacts in other projects.

Workspaces

Top-level containers for organizing multiple projects and teams.

• A workspace typically includes several engineers.
• Engineers have access controls scoped to the projects within their workspace.