OpenSimulator Internals/Connector Architecture
OpenSimulator Internals/Connector Architecture
Overview
Connectors are the HTTP client layer that sits between region simulators and ROBUST grid services. Each connector implements a service interface (e.g. IAssetService, IPresenceService) using HTTP calls to the corresponding ROBUST handler.
The same interface may be implemented by:
- A local connector -- calls the service directly in-process (standalone mode or co-located services).
- A remote connector -- makes HTTP calls to a ROBUST server.
- An HG connector -- wraps the remote connector with hypergrid-specific logic.
Region code calls only the interface. Which implementation is loaded depends on configuration ([Architecture] section of the ini files).
See OpenSimulator Internals/ROBUST Services for the server-side service implementations.
Connector Pattern
All remote connectors follow the same pattern:
- Constructor receives IConfigSource and reads the service URL from config.
- Each method serialises parameters to a REST or XMLRPC request.
- Sends HTTP POST/GET/DELETE to the ROBUST handler endpoint.
- Deserialises the response and returns the result.
The HTTP client layer is WebUtil (OpenSim/Framework/WebUtil.cs), which handles serialisation, connection pooling, and error logging.
See OpenSimulator Internals/Connector Architecture/Asset Connector for a fully worked example of the pattern including both client and server-side handler code.
Individual Connector Pages
| Connector | Service Interface | Notes |
|---|---|---|
| OpenSimulator Internals/Connector Architecture/Asset Connector | IAssetService | Includes server-side handler detail. HG variant wraps with foreign asset server logic. |
| OpenSimulator Internals/Connector Architecture/GridUser Connector | IGridUserService | Tracks last position, login/logout timestamps, home region. |
| OpenSimulator Internals/Connector Architecture/Presence Connector | IPresenceService | Online status, session tracking, region assignment. |
| OpenSimulator Internals/Connector Architecture/UserAccount Connector | IUserAccountService | User account CRUD. Known bug: CreateUser() sends first name as email value. |
| OpenSimulator Internals/Connector Architecture/Inventory Connector | IInventoryService | XInventory protocol. UpdateFolder() URL-encodes Name; AddFolder() does not. |
| OpenSimulator Internals/Connector Architecture/Authentication Connector | IAuthenticationService | Password and token authentication, impersonation mechanism. |
| OpenSimulator Internals/Connector Architecture/Avatar Connector | IAvatarService | Appearance storage. ResetAvatar() log erroneously says "SetItems reply". |
| OpenSimulator Internals/Connector Architecture/Friends Connector | IFriendsService | Friend list, online notifications. |
| OpenSimulator Internals/Connector Architecture/Grid Connector | IGridService | Region registration, lookup, neighbour queries. |
| OpenSimulator Internals/Connector Architecture/Simulation Connector | ISimulationService | Inter-simulator agent and object transfer. QueryAccess, CreateAgent, UpdateAgent, CloseAgent, CreateObject. |
| OpenSimulator Internals/Connector Architecture/UserAgent Connector | IUserAgentService | HG-only. Home region lookup, login to foreign grid, session verification. |
| OpenSimulator Internals/Connector Architecture/Gatekeeper Connector | IGatekeeperService | HG-only. Foreign grid entry point. GetHyperlinkRegion, LoginAgentToGrid. |
HG Connectors
HyperGrid introduces additional connectors that wrap or replace the standard ones:
- UserAgent Connector -- used by the source grid to contact the avatar's home grid UserAgent service during HG teleport.
- Gatekeeper Connector -- used to contact a foreign grid's Gatekeeper during HG destination resolution.
- HGAsset Connector -- used by HGInventoryAccessModule to fetch/push assets between grids (via HGAssetMapper).
These are documented in the individual connector pages above and in:
- OpenSimulator Internals/Code Map/HGEntityTransferModule
- OpenSimulator Internals/Code Map/InventoryAccessModule
Configuration
Connectors are selected in the [Architecture] ini include files:
- config-include/StandaloneCommon.ini -- standalone mode, services loaded in-process.
- config-include/GridCommon.ini -- grid mode, remote connectors used.
- config-include/HGCommon.ini -- hypergrid additions.
The [ServiceList] section of Robust.ini selects which ROBUST handlers are loaded. The [Modules] section of OpenSim.ini selects which connectors the simulator loads.