Understanding Instances in Vidos

An instance is a fundamental concept in Vidos that represents a specific configuration of a service within a region. Understanding instances is key to grasping how Vidos provides flexible, application-specific services while maintaining regional boundaries.

What are Instances?

An instance represents a distinct configuration of a Vidos service that operates within a region. Each instance exists to serve a specific application’s needs, independent of other instances of the same service. For example, within a region, you might have multiple authorizer instances - one configured for an application that requires OAuth authentication, and another for an application that uses API keys.

graph TD
    subgraph "Authorizer Service"
        A1[Authorizer Instance 1: Mdl]
        A2[Authorizer Instance 2: Payments]
    end

    UC1[Identity Verification] --> A1
    UC2[Authentication] --> A1
    UC3[Financial Transactions] --> A2

    classDef instance fill:#e1f5fe,stroke:#0277bd,stroke-width:1px
    classDef usecase fill:#fff3e0,stroke:#e65100,stroke-width:2px

    class A1,A2 instance
    class UC1,UC2,UC3 usecase

The diagram above illustrates how different use cases can leverage specialized instances of the Authorizer service. Identity Verification and Authentication both use the Mdl (Mobile Driving License) instance, which is configured for secure identity verification, while Financial Transactions use the Payments instance configured specifically for handling financial operations.

Regional Context

Instances exist within regions, which are fundamental organizational units in Vidos. This relationship means that:

• Each instance belongs to a specific region
• An instance’s scope is limited to its region
• Management of instances occurs within their region
• Data and processing remain within regional boundaries

Instance Management

Each instance-capable service in Vidos has a corresponding management service within the same region. This management relationship reflects three key aspects:

• Creation and removal of instances
• Configuration of instance behavior
• Management of instance status

Instance-Capable Services

In Vidos, four core services support instances:

• Authorizer instances handle different authentication mechanisms
• Resolver instances manage identifier and address resolution
• Verifier instances perform different types of verification
• Validator instances apply varying validation rules

Each of these services can exist as multiple instances within a region, with each instance tailored to specific application requirements.

Configuration and State

Every instance maintains:

1. Configuration: The settings that define its behavior for a specific application
2. State: The information needed for operation

These aspects are managed regionally, ensuring that each instance maintains its intended purpose while operating within regional boundaries.