Revision as of 14:02, 30 April 2014

Introduction

For various reasons, sometimes one wants to have 2 or more separate installations of OpenSimulator rather than one large grid. However, this creates major inconvenience if users need to login to both grids - a user account needs to be created on both and they will have entirely different inventory (and hence clothing, body parts and attachments) between OpenSimulator installations.

One approach is to have a single user account on one of the grids and allow the user to travel to other grids via the Hypergrid.

Another approach, which we will detail here, is to share the user account, authentication, avatar, asset and inventory services between multiple installations but not other services, such as grid or griduser. This will allow the two grids to remain seperate (one will not be able to teleport between regions on different grids) whilst allow the user to retain the same account details, inventory and attachments between multiple OpenSimulator installations.

Steps

These are steps for sharing services between two separate OpenSimulator installations (Grid A and Grid B). I will assume that both installations are running in grid mode. I will assume that each installation is hosted on a separate machine or set of machines. If both installations are on the same machine then you will need to adjust default port numbers on non-shared services so that they will not clash.

We will also assume that Grid A and Grid B are running on the same local network. The ROBUST service addresses are as follows.

Grid A - 192.168.1.2 (8002 public port, 8003 private port)
Grid B - 192.168.1.3 (8002 public port, 8003 private port)

Step 1: Decide which grid installation will host the shared services

One grid's ROBUST instance (more in sophisticated setups) will host the services to be shared between multiple installations. The other grid's simulator and ROBUST configuration will be changed so that it uses the shared services rather than its own. In these instructions, Grid A will host the shared services.

Step 2: Configure the simulators on Grid B to use Grid A's services

On Grid B, we need to configure the simulators so that they connected to Grid B for some service types but Grid A for others.

The services that need to be shared are

• Asset - to share asset used within inventory items.
• Authentication - so that login passwords are authenticated against the same stored hashes.
• Avatar - to share information about worn attachments, clothing and body parts.
• Inventory - to share inventory items.
• UserAccount - to share user account information.

To do this, we configure the ServerURI in each relevant service section to connect to the Grid A services rather than Grid B. In this example, the configuration would be as follows

[AssetService]
    AssetServerURI = "http://192.168.1.2:8003"
 
[AuthenticationService]
    AuthenticationServerURI = "http://192.168.1.2:8003"
 
[AvatarService]
    AvatarServerURI = "http://192.168.1.2:8003"
 
[InventoryService]
    InventoryServerURI = "http://192.168.1.2:8003"
 
[UserAccountService]
    UserAccountServerURI = "http://192.168.1.2:8003"

Step 3: Configure Grid B's LLLoginService to use Grid A services where appropriate

As well as redirecting Grid B's simulators to use Grid A's services, we need to configure Grid B's login service to use Grid A's services.

We need to do this because the login service consults these other services either to identify and authenticate the user (Authentation and UserAccount services) or get information to populate the login response (Avatar, Inventory).

The configuration here is more complex because we need to tell the Grid B login service to use connectors to access Grid A's services rather than instantiate it's own local service instances.

Step 3A: Configure the Login Service to use connectors for shared services

This is done in the [LoginService] section of Robust.ini. Instead of specifying services in local service DLLs, we ask the login service to instantiate connectors.

For instance, the usual UserAccountService configuration here is

[LoginService]
    UserAccountService = "OpenSim.Services.UserAccountService.dll:UserAccountService"

which instantiates a local user account service from the OpenSim.Services.UserAccountService.dll. But for a connector configuration. this becomes

[LoginService]
    UserAccountService = "OpenSim.Services.Connectors.dll:UserAccountServicesConnector"

In all, the service sections of [LoginService] change from

[LoginService]
    UserAccountService = "OpenSim.Services.UserAccountService.dll:UserAccountService"
    AuthenticationService = "OpenSim.Services.AuthenticationService.dll:PasswordAuthenticationService"
    InventoryService = "OpenSim.Services.InventoryService.dll:XInventoryService"
    AvatarService = "OpenSim.Services.AvatarService.dll:AvatarService"

to

[LoginService]
    UserAccountService = "OpenSim.Services.Connectors.dll:UserAccountServicesConnector"
    AuthenticationService = "OpenSim.Services.Connectors.dll:AuthenticationServicesConnector"
    InventoryService = "OpenSim.Services.Connectors.dll:XInventoryServicesConnector"
    AvatarService = "OpenSim.Services.Connectors.dll:AvatarServiceConnector"

Problems

Tight coupling

Once somebody has a user account they can move indiscrimnately between the installations sharing those services.

Friends Service

If the friends service is shared, then users will see friends who are at other grids. This may be confusing, since they will be able to communicate with them but not join them until they have logged on to the same grid.

On the other hand, if the friends service is not shared then users will have to manage a separate friends list on each server.