TenantDbContextPoolExtensions class

Namespace: Tenantry.EfCore.Extensions · Package: Tenantry.EfCore · API reference

DbContext pooling for applications that give each tenant its own database.

public static class TenantDbContextPoolExtensions

MethodsCopy Anchor Link

AddTenantDbContextPool<TContext, TKey>(IServiceCollection, Action<IServiceProvider, DbContextOptionsBuilder>, int)Copy Anchor Link

Pools TContext for a database per tenant. Registers a scoped TContext and IDbContextFactory<TContext>, both leasing from one pool, and connects every lease to the current tenant's database through ITenantConnectionStringResolver<TKey>.

public static IServiceCollection AddTenantDbContextPool<TContext, TKey>(this IServiceCollection services, Action<IServiceProvider, DbContextOptionsBuilder> optionsAction, int poolSize = 1024) where TContext : DbContext where TKey : IEquatable<TKey>, IParsable<TKey>

Type parameters:

• TContext: The context type. It needs a constructor that takes only its options.
• TKey: The tenant identifier type.

Parameters:

• services IServiceCollection: The application's service collection.
• optionsAction Action<IServiceProvider, DbContextOptionsBuilder>: Configures the context's options, without a connection string: each lease is connected to the current tenant's database.
• poolSize int: The most contexts the pool keeps for reuse.

Returns: IServiceCollection

A pooled context keeps its connection string when it returns to the pool, so resolving the connection string in a regular AddDbContextPool callback (which runs once) would send every tenant to the first tenant's database. Here, configure the provider without a connection string; each lease gets the current tenant's. Leasing without a current tenant throws TenantNotResolvedException.

A guard also checks each pooled context before it opens a connection and before every command it runs, including on a connection that is already open: the connection must have been set for the context's current lease and for the tenant that is current now. Otherwise it throws TenantIsolationViolationException rather than use another tenant's database.

The scoped TContext resolves the connection string synchronously, so it needs TenantConnectionStringOptions<TKey>.GetConnectionString. With only an asynchronous delegate, use IDbContextFactory<TContext>.CreateDbContextAsync. The context must have a constructor that takes only its options, as MultiTenantDbContext<TKey> does.

builder.Services.AddTenantry<Guid>(tenant =>
{
    tenant.ResolveFromHeader("X-Tenant-Id");
    tenant.UseStore<AppTenantStore>();
    tenant.UseConnectionStrings(options =>
        options.GetConnectionString = t => $"Server=db;Database=app_{t.TenantId};Integrated Security=true");
    tenant.AddEfCoreIsolation();
});

// No connection string here: each lease is connected to the current tenant's database. builder.Services.AddTenantDbContextPool<AppDbContext, Guid>((sp, options) =>     options.UseSqlServer().AddTenantInterceptors(sp)); ```