Disclaimer: I have already read and seen LOTS of tutorials/videos and unfortunately am still not clear on how this works. What I know:
At application Startup ConfigureAuth is executed which contains
app.CreatePerOwinContext(GE.Core.DbContexts.ApplicationDbContext.Create);
This in turn goes to ApplicationDbContext class and establishes a connection
public class ApplicationDbContext : IdentityDbContext<ApplicationUser, Role, int, UserLogin, UserRole, UserClaim>
{
public DbSet<User> geUsers { get; set; }
public ApplicationDbContext(string connString)
: base(connString)
{
Database.SetInitializer(new MySqlInitializer());
}
public static ApplicationDbContext Create()
{
return new ApplicationDbContext("name=GEContext");
}
}
Question 1: is there a way to not establish this connection until the login page appears? OR What if i keep a dummy connection in my we.config which should be invalid as soon as i sign-in and replaced with the actual connection?
After the login page is loaded, i take a schoolCode at Login and want to establish a database connection based on that schoolCode. e.g. name = GEContext_[schoolCode]. My Web.config will contain many connectionStrings like this.
Question 2 When I Debug my application, every time a page is loaded, Create method of ApplicationDbContext is hit and a default connection
return new ApplicationDbContext("name=GEContext");
always seems to establish..What's actually going on?
Here is my remaining code:
ApplicationUserManager
public class ApplicationUserManager : UserManager<ApplicationUser, int>
{
public ApplicationUserManager(IUserStore<ApplicationUser, int> store)
: base(store)
{
}
public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context)
{
var manager = new ApplicationUserManager(new UserStore<ApplicationUser, Role, int, UserLogin, UserRole, UserClaim>(context.Get<ApplicationDbContext>()));
....
}
}
I have another GEContext
[DbConfigurationType(typeof(MySql.Data.Entity.MySqlEFConfiguration))]
public class GEContext : DbContext
{
public GEContext(string connString):base(connString)
{
this.Configuration.LazyLoadingEnabled = false;
Database.SetInitializer(new MySqlInitializer());
}
}
which works fine from the controller
private static string schoolCode = (string)System.Web.HttpContext.Current.Session["SchoolCode"];
[Authorize]
public ActionResult About()
{
YearRepository repYear = new YearRepository("name=GEContext_" + schoolCode);
}
How do i do the same with applicationdbcontext? but above all questions how does it work?
Related
tl;dr I am not cleaning up the context, as I assume that is all handled with DI/automatically being scoped (this might be my problem)
I have a ASP.NET Core that utilizes EF Core and after a while my site being live, the memory on the dotnet process for the app shoots to 1GB, at that point I see a lot of SQL Timeout errors. If I kill the process then those errors go away after the process re-spawns on a request for a while and it repeats..
I suspect somewhere in my code I have a memory leak or my design is not correct that results in something not cleaning up properly.
Here is my setup.
public void ConfigureServices(IServiceCollection services)
{
services.AddMemoryCache();
var connectionString = Configuration.GetSection("GeneralSettings:ConnectionString").Value;
services.AddDbContext<CryptoCalContext>(options => options.UseSqlServer(connectionString));
...
services.AddScoped<IDbService, DbService>();
}
I pass the context to a service(DbService) handles all my DB calls
public class DbService : IDbService
{
public CryptoCalContext DbContext { get; set; }
public DbService(CryptoCalContext context, ...)
{
DbContext = context;
...
}
public List<CategoryDto> Categories
{
get
{
return MemoryCache.GetOrCreate("Categories", entry =>
{
entry.SlidingExpiration = TimeSpan.FromMinutes(GeneralSettings.CacheExperationMinutes);
return DbContext.Categories.Include(x => x.Articles).Select(x => new CategoryDto(x)).ToList();
});
}
}
}
And in my calls to db, I do not make use of "using blocks" or call dispose.
I assume each call creates a separate db connection when needed so I do not do any of that (maybe this is where I am going wrong)
public class HomeController : BaseController
{
public HomeController(IDbService dbService ,..)
: base(dbService, ...)
{
}
}
public class BaseController : Controller
{
public IDbService DbService { get; set; }
public BaseController(IDbService dbService, ...)
{
DbService = dbService;
}
}
In my controllers, I simply do DbService.Categories, one of many different calls in my DbService, I put this example to illustrate that I do zero cleaning
EDIT:
public class CryptoCalContext : DbContext
{
public CryptoCalContext(DbContextOptions<CryptoCalContext> options)
: base(options)
{
}
public CryptoCalContext()
{
}
...Properties...
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
base.OnConfiguring(optionsBuilder);
}
}
Does anyone know how we can inject context into User Manager > MongoDB serStore at runtime in .net core 2.0.
We cannot do this at startup due to the context being dynamic but the UserStore is not accessible and UserManager has too many variables to new up, and it is wrong. Are there any solutions?
public class UserStore<TUser> :
IUserPasswordStore<TUser>,
IUserRoleStore<TUser>,
IUserLoginStore<TUser>,
IUserSecurityStampStore<TUser>,
IUserEmailStore<TUser>,
IUserClaimStore<TUser>,
IUserPhoneNumberStore<TUser>,
IUserTwoFactorStore<TUser>,
IUserLockoutStore<TUser>,
IQueryableUserStore<TUser>,
IUserAuthenticationTokenStore<TUser>
where TUser : IdentityUser
{
private readonly IMongoCollection<TUser> _Users;
//THIS IS WHERE WE WANT TO INJECT THE users AT RUNTIME
public UserStore(IMongoCollection<TUser> users)
{
_Users = users;
}
public virtual void Dispose()
{
// no need to dispose of anything, mongodb handles connection pooling automatically
}
public virtual async Task<IdentityResult> CreateAsync(TUser user, CancellationToken token)
{
await _Users.InsertOneAsync(user, cancellationToken: token);
return IdentityResult.Success;
}
unfortunately users is null at startup, and should be as the tenant has not been created at that point.
We have also been using the saaskit.Multitenancy and just can't find a solution.
Any help would be much appreciated.
Thanks
i think u need a generic repository to act as a wrapper for IMongoCollection then inject the repository inside controllers
public class Repository<T>
{
public IMongoCollection<T> Collection { get; private set; }
public Repository(IDbFactory dbFactory)
{
MongoClient client = new MongoClient("ur connection string");
this.Collection = client.GetDatabase("db").GetCollection<T>(typeof(T).Name);
}
public T Find(Expression<Func<T, bool>> filter)
{
return this.Collection.AsQueryable<T>().FirstOrDefault<T>(filter);
}
public async Task<T> FindAsync(Expression<Func<T, bool>> filter)
{
return await this.Collection.AsQueryable<T>().FirstOrDefaultAsync<T>(filter);
}
// here add more methods
}
then register the dependency as below inside Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddTransient(typeof(IRepository<>), typeof(Repository<>));
services.AddMvc();
}
finally inside controllers u inject the generic repository, also dont forget to Implement the IDisopsible in genereic repository
public class ProductController : Controller
{
private readonly IRepository<Product> _productRepository = null;
public ProductController(IRepository<Product> productRepository)
{
this._productRepository = productRepository;
}
}
My Entity framework context is as following
public partial class MyContext : DbContext, IMyContext
{
static MyContext()
{
System.Data.Entity.Database.SetInitializer<MyContext>(null);
}
public MyContext()
: base("Name=MyContext")
{
}
I am resolving it through autofac in the following way
builder.RegisterType(typeof(MainContext)).As(typeof(DbContext)).InstancePerLifetimeScope();
builder.RegisterType<MainContext>().As<IMainContext>().InstancePerRequest();
This db context gets called in repository layer
#region Fields
private readonly IMyContext _context;
#endregion
#region Constructors and Destructors
public EmployeeRepository(IMyContext context)
{
_context = context;
}
#endregion
public void Create(Employee emp)
{
this._context.Employee.Add(emp);
}
Now my issue is , I want to set the connection string dynamically per call. The connection string will be passed through a webapi which i want to pass on to this context. Can anyone help me how can i do that? I am confused about autofac here. Secondly how can i make sure each call sets connection string and does not cache it.
You can use a factory that will build the context and set the connectionstring for you.
public interface IContextFactory
{
IContext GetInstance();
}
public class MyContextFactory : IContextFactory
{
public IContext GetInstance()
{
String connectionString = this.GetConnectionString(HttpContext.Current);
return new MyContext(connectionString);
}
private String GetConnectionString(HttpContext context)
{
// do what you want
}
}
builder.RegisterType<MyContextFactory>()
.As<IContextFactory>()
.InstancePerRequest();
builder.Register(c => c.Resolve<IContextFactory>().GetInstance())
.As<IContext>()
.InstancePerRequest();
If you can't get connectionstring based on HttpContext, you can change contextFactory implementation to expect initialization by WebAPI before creating the instance. For example :
public interface IContextFactory
{
IContext GetInstance();
void Initialize(String connectionString);
}
public class MyContextFactory : IContextFactory
{
private String _connectionString;
public void Initialize(String connectionString)
{
this._connectionString = connectionString;
}
public IContext GetInstance()
{
if (this._connectionString == null)
{
throw new Exception("connectionString not initialized");
}
return new MyContext(this._connectionString);
}
}
At the beginning of your web API call (through attribute for example), you can call the Initialize method. Because the factory is InstancePerRequest you will have one instance for the duration of the request.
By the way, I'm not sure to understand this registration
builder.RegisterType(typeof(MainContext)).As(typeof(DbContext)).InstancePerLifetimeScope();
builder.RegisterType<MainContext>().As<IMainContext>().InstancePerRequest();
It looks buggy because you will have 2 different registration of the same type and not for the same scope, is it intended ? Furthermore, it doesn't sound a good idea to register a DbContext, do you need this registration ?
The following registration looks better :
builder.RegisterType<MainContext>()
.As<IMainContext>()
.As<DbContext>()
.InstancePerRequest();
I have a method in HomeController, that I'm trying to access through URL, like this:
http://localhost/web/home/GetSmth
First time it works, but after refreshing page, I get this error:
The operation cannot be completed because the DbContext has been disposed.
As the title states, I'm trying to use Castle Windsor and DbContext per request.
public class Installer1 : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(Classes.FromThisAssembly()
.BasedOn<IController>()
.LifestyleTransient()
);
var connString = ConfigurationManager.ConnectionStrings["MainDbContext"].ConnectionString;
container.Register(Component.For<MainDbContext>().DependsOn(Property.ForKey("conn").Eq(connString)).LifeStyle.PerWebRequest);
container.Register(Component.For<ISomeService>().ImplementedBy<SomeService>());
}
}
HomeController looks like this:
public class HomeController : Controller
{
private ISomeService _someService;
public HomeController(ISomeService someService)
{
_someService = someService;
}
public ActionResult Index()
{
return View();
}
public JsonResult GetSmth()
{
var data = _someService.GetData().ToList();
return Json(data, JsonRequestBehavior.AllowGet);
}
}
You are registering ISomeService with the default lifecycle, which is singleton. Once it's created, it will keep using the same DbContext. Simplest solution is to change its lifecycle to per request or transient.
container.Register(Component.For<ISomeService>()
.ImplementedBy<SomeService>()
.LifeStyle.PerWebRequest);
I am creating an ASP.NET MVC 3 e-commerce website and I am currently working on the admin area where you can add/edit products. To create the UI for the product page I am using Telerik MVC controls.
My problem is that when I added a second telerik grid which both retrieve data from the database through an ajax call I receive a couple different errors listed below:
{"There is already an open DataReader associated with this Command
which must be closed first."}
{"The connection was not closed. The connection's current state is
connecting."}
Database Context Code
public interface IUnitOfWork
{
void Commit();
}
public class GSPDataContext : DbContext, IUnitOfWork
{
/* (omitted) IDbSet's for entities */
public GSPDataContext()
: base("GSPConnectionString")
{
}
public virtual IDbSet<T> DbSet<T>() where T : class
{
return Set<T>();
}
public virtual void Commit()
{
base.SaveChanges();
}
}
Generic Repository Code
public class Repository<T> : IRepository<T> where T : class
{
private GSPDataContext m_dataContext;
private readonly IDbSet<T> m_entity;
public Repository(GSPDataContext dataContext)
{
if (dataContext == null)
throw new ArgumentException();
m_dataContext = dataContext;
m_entity = m_dataContext.Set<T>();
}
public T GetById(int id)
{
return this.m_entity.Find(id);
}
public void Insert(T entity)
{
if (entity == null)
throw new ArgumentException();
this.m_entity.Add(entity);
//this.m_dataContext.SaveChanges();
}
public void Delete(T entity)
{
if (entity == null)
throw new ArgumentException();
this.m_entity.Remove(entity);
//this.m_dataContext.SaveChanges();
}
public virtual IQueryable<T> Table
{
get
{
return this.m_entity;
}
}
}
Ninject Code
private static void RegisterServices(IKernel kernel)
{
//Customer
kernel.Bind<IAddressValidationService>().To<AddressValidationService>().InRequestScope();
kernel.Bind<ICustomerService>().To<CustomerService>().InRequestScope();
kernel.Bind<ICustomerProductService>().To<CustomerProductService>().InRequestScope();
//Authentication
kernel.Bind<IOpenIDLoginService>().To<OpenIDLoginService>().InRequestScope();
kernel.Bind<IAuthenticationService>().To<FormsAuthenticationService>().InRequestScope();
//Products
kernel.Bind<IProductService>().To<ProductService>().InRequestScope();
kernel.Bind<IRecentlyViewedProductService>().To<RecentlyViewedProductService>().InRequestScope();
kernel.Bind<IProductPictureService>().To<ProductPictureService>().InRequestScope();
kernel.Bind<ICategoryService>().To<CategoryService>().InRequestScope();
kernel.Bind<IPictureService>().To<PictureService>().InRequestScope();
//Shopping Cart
kernel.Bind<IShoppingCartService>().To<ShoppingCartService>().InRequestScope();
//Shipping and Payment
kernel.Bind<IShippingService>().To<ShippingService>().InRequestScope();
kernel.Bind<IPaymentService>().To<PaymentService>().InRequestScope();
//Orders
kernel.Bind<IOrderCalculationService>().To<OrderCalculationService>().InRequestScope();
kernel.Bind<IOrderProcessingService>().To<OrderProcessingService>().InRequestScope();
kernel.Bind<IOrderService>().To<OrderService>().InRequestScope();
//
kernel.Bind<IEncryptionService>().To<EncryptionService>().InRequestScope();
kernel.Bind<ILogger>().To<LoggingService>().InRequestScope();
kernel.Bind<IWebManager>().To<WebManager>().InRequestScope();
//Messages
kernel.Bind<IEmailService>().To<EmailService>().InRequestScope();
kernel.Bind<IMessageTemplateService>().To<MessageTemplateService>().InRequestScope();
kernel.Bind<IWorkflowMessageService>().To<WorkflowMessageService>().InRequestScope();
//Data
kernel.Bind<GSPDataContext>().ToSelf().InSingletonScope();
kernel.Bind<IUnitOfWork>().ToMethod(ctx => ctx.Kernel.Get<GSPDataContext>()).InSingletonScope();
kernel.Bind(typeof (IRepository<>)).To(typeof (Repository<>)).InRequestScope();
kernel.Bind<IWorkContext>().To<WebWorkContext>().InRequestScope();
}
I suspect it has something to do with how ninject is managing the lifetimes of the various services, but I am not sure what I need to do to make it work.
Any advice would be much appreciated.
Thanks
UPDATE
According to Remo's comment I change my code to the following:
//Data
kernel.Bind<GSPDataContext>().ToSelf().InRequestScope();
kernel.Bind<IUnitOfWork>().ToMethod(ctx => ctx.Kernel.Get<GSPDataContext>()).InRequestScope();
kernel.Bind(typeof (IRepository<>)).To(typeof (Repository<>)).InRequestScope();
And I am now getting the following error:
The ObjectContext instance has been disposed and can no longer be used
for operations that require a connection.
Any ideas?
No, it has nothing to do with how Ninject manages lifetimes. But it has to do how you configured the lifecycles.
It is important that a new DbContext is used for each request. This has to be InRequestScope.