Introduction

Multitenancy Levels

Elsa supports multitenancy both within a shared database and through separate databases for each tenant.

Shared Database

Each entity has a TenantId property that links them to a specific tenant. This setup allows for a database with multiple tenants and their related information, such as workflows and any other entity derived from the Entity base class.

Separate Database

To ensure strong tenant separation, each database-connected module can be set up to determine the correct connection string at runtime. This is done using a factory delegate that uses the IServiceProvider to identify the current tenant via the ITenantAccessor service.

Tenant

A tenant is represented by the Tenant class:

public class Tenant : Entity
{
   public string Name { get; set; }
   public IConfiguration Configuration { get; set; }
}

A tenant has a name and a configuration object. This configuration allows for tenant-specific settings like connection strings and host names.

Tenant Resolution Pipeline

The Tenant Resolution Pipeline is a group of components that identify the current tenant from the application context. In an ASP.NET Core app, these components usually look at the current HTTP request. For instance, the HostTenantResolver checks the request's host, and if it finds a tenant linked to that host, it selects that tenant as the current one.

The following packages provide the following resolvers:

• Elsa.Identity

  • ClaimsTenantResolver

  • CurrentUserTenantResolver

• Elsa.Tenants.AspNetCore

  • HeaderTenantResolver

  • HostTenantResolver

  • RoutePrefixTenantResolver

Tenants Provider

The Tenants Provider is a service that lists all the tenants registered in your application. Elsa provides the following built-in implementations:

• DefaultTenantsProvider

  • Produces a single tenant that represents the one and only tenant in a single-tenant setup. This is the default provider.

• ConfigurationTenantsProvider

  • Produces tenants from the TenantsOptions options class, which can be configured from e.g. appsettings.json.

• StoreTenantsProvider

  • The ITenantStore service manages tenants with EF Core and MongoDB options. This allows tenants to be stored, added, updated, and removed from the database