vocabulary:
  name: Sozu Vocabulary
  description: >-
    Domain vocabulary for the Sōzu HTTP reverse proxy, covering load balancing,
    traffic management, TLS termination, runtime configuration, and Rust-based
    systems programming concepts used in the sozu-proxy project.
  tags:
    - Proxy
    - Reverse Proxy
    - Load Balancing
    - Rust
    - Open Source
  terms:
    - term: Reverse Proxy
      definition: >-
        A server that sits in front of one or more backend servers, intercepting
        client requests and forwarding them to the appropriate upstream service,
        providing load balancing, TLS termination, and traffic management.
      category: Networking
    - term: Cluster
      definition: >-
        A logical grouping of backend application instances in Sozu that receive
        forwarded traffic. Clusters can be added, removed, or modified at runtime
        without interrupting existing connections.
      category: Configuration
    - term: Backend
      definition: >-
        An individual upstream server instance within a Sozu cluster, identified
        by IP address and port, to which the proxy forwards incoming requests.
      category: Configuration
    - term: Frontend
      definition: >-
        A Sozu configuration entity binding a network listener (IP, port, protocol)
        to a cluster, defining how incoming connections are matched and routed.
      category: Configuration
    - term: Listener
      definition: >-
        A network socket configuration in Sozu that accepts incoming connections
        on a specified IP address, port, and protocol (HTTP or HTTPS).
      category: Configuration
    - term: Runtime Configuration
      definition: >-
        Sozu's core capability to accept configuration changes (adding backends,
        updating certificates, modifying routes) while actively serving traffic,
        without requiring a process restart.
      category: Operations
    - term: Protobuf IPC
      definition: >-
        The inter-process communication mechanism used by Sozu, where external
        tools send Protocol Buffer (protobuf) encoded messages over a Unix socket
        to configure and control the proxy at runtime.
      category: Protocol
    - term: Unix Socket
      definition: >-
        The communication channel used by the Sozu command interface, providing
        a secure local socket path for sending configuration commands to the
        proxy process.
      category: Protocol
    - term: TLS Termination
      definition: >-
        The process of decrypting inbound HTTPS connections at the proxy level,
        allowing backend servers to receive unencrypted HTTP traffic while clients
        communicate securely.
      category: Security
    - term: SNI (Server Name Indication)
      definition: >-
        A TLS extension that allows the Sozu proxy to select the appropriate
        certificate for a connection based on the hostname requested by the client,
        enabling multiple virtual hosts on a single IP address.
      category: Security
    - term: ACME
      definition: >-
        Automated Certificate Management Environment — a protocol used by Sozu
        to automatically request, renew, and manage TLS certificates from certificate
        authorities like Let's Encrypt.
      category: Security
    - term: Load Balancing
      definition: >-
        The distribution of incoming network requests across multiple backend server
        instances in a cluster to optimize resource utilization and prevent overload.
      category: Networking
    - term: Worker Process
      definition: >-
        One of the worker processes managed by the Sozu main/supervisor process
        that handles actual HTTP/HTTPS traffic forwarding and connection management.
      category: Architecture
    - term: sozu-command-lib
      definition: >-
        The Rust crate that contains the protobuf IPC schema, configuration parser,
        replicated state structures, channels, and file descriptor passing helpers
        used by both the Sozu library and binary.
      category: Development
    - term: Immutable Infrastructure
      definition: >-
        An operational paradigm where servers are never modified after deployment
        but replaced with new instances; Sozu's runtime configurability supports
        this model by enabling zero-downtime updates.
      category: Operations
    - term: Hot Reload
      definition: >-
        Sozu's ability to update itself and its configuration while continuing
        to handle traffic, passing file descriptors between processes to maintain
        active connections.
      category: Operations