Ida  Nader

Ida Nader

1598179680

What Is Circuit Breaker and How to implement It With .NET Core?

What is Circuit Breaker?

circuit breaker is an automatically operated electricalswitch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. — Wikipedia.

But, wait….!

This is a Software Programming topic, and why I’m bring something related to Electrical Technology into this topic?

Because the way we apply Circuit Breaker Pattern in Software Programming is very similar. And I just want to bring something that you are familiar with in order to make the topic easier to understand.

Back to the definition of Circuit Breaker in Software Programming…

Circuit Breaker pattern is used to detect failures and encapsulates the logic of preventing a failure from constantly recurring, during maintenance, temporary external system failure or unexpected system difficulties. —Wikipedia

Bear in mind that, It’s not available to prevent the broken service, but not to make it worse than it was. While other design patterns are born for making our solution easy to maintain, maximize reusability, better performance… then Circuit Breaker is the one for “when sh*t happens”.

image source: me.me

Why Circuit Breaker?

Back to several years ago — the time I started digging and applying Microservices architecture (MSA), MSA was something very new with not only me but also other developers. Nowadays, you can easily find technical articles, sample projects and case studies about MSA as it’s becoming very popular. There is a fact which can’t be denied that MSA brings so many advantages and benefits, it also makes our solution brittle because a request from user will need to call multiple micro-services. It replaces the in-memory calls of a Monolithic architecture with remote calls across the network, which works well when all services are up and running. But when one or more services are unavailable, slow network connection or timeout… it results in a cascading failure across the application.

And, Circuit Breaker is here to help us can build a fault-tolerant and resilient system that can survive gracefully when key services are either unavailable or have high latency. Circuit Breaker pattern enables an application to detect whether the fault has been resolved. If the problem appears to have been fixed, the application can try to invoke the operation.

Circuit Breaker States

Image for post

Photo by Blake Weyland on Unsplash

Although the name “Circuit Breaker” is mimicked from Electrical Technology, in software programming, Circuit Breaker can do much more than turning on/off the electricity (tripping).

  • Both of them can detect when there is a problem and automatically turn on. But while Circuit Breaker in software programming can turn off automatically, then Circuit Breaker in Electrical Technology couldn’t.
  • Besides having fully opened and fully closed state, Circuit Breaker in software programming can have an intermediate state, called “Half-open” where an application can operate at degraded functionalities.

#polly #software-architecture #design-patterns #circuit-breaker #microservices

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What Is Circuit Breaker and How to implement It With .NET Core?
Einar  Hintz

Einar Hintz

1602560783

jQuery Ajax CRUD in ASP.NET Core MVC with Modal Popup

In this article, we’ll discuss how to use jQuery Ajax for ASP.NET Core MVC CRUD Operations using Bootstrap Modal. With jQuery Ajax, we can make HTTP request to controller action methods without reloading the entire page, like a single page application.

To demonstrate CRUD operations – insert, update, delete and retrieve, the project will be dealing with details of a normal bank transaction. GitHub repository for this demo project : https://bit.ly/33KTJAu.

Sub-topics discussed :

  • Form design for insert and update operation.
  • Display forms in modal popup dialog.
  • Form post using jQuery Ajax.
  • Implement MVC CRUD operations with jQuery Ajax.
  • Loading spinner in .NET Core MVC.
  • Prevent direct access to MVC action method.

Create ASP.NET Core MVC Project

In Visual Studio 2019, Go to File > New > Project (Ctrl + Shift + N).

From new project window, Select Asp.Net Core Web Application_._

Image showing how to create ASP.NET Core Web API project in Visual Studio.

Once you provide the project name and location. Select Web Application(Model-View-Controller) and uncheck HTTPS Configuration. Above steps will create a brand new ASP.NET Core MVC project.

Showing project template selection for .NET Core MVC.

Setup a Database

Let’s create a database for this application using Entity Framework Core. For that we’ve to install corresponding NuGet Packages. Right click on project from solution explorer, select Manage NuGet Packages_,_ From browse tab, install following 3 packages.

Showing list of NuGet Packages for Entity Framework Core

Now let’s define DB model class file – /Models/TransactionModel.cs.

public class TransactionModel
{
    [Key]
    public int TransactionId { get; set; }

    [Column(TypeName ="nvarchar(12)")]
    [DisplayName("Account Number")]
    [Required(ErrorMessage ="This Field is required.")]
    [MaxLength(12,ErrorMessage ="Maximum 12 characters only")]
    public string AccountNumber { get; set; }

    [Column(TypeName ="nvarchar(100)")]
    [DisplayName("Beneficiary Name")]
    [Required(ErrorMessage = "This Field is required.")]
    public string BeneficiaryName { get; set; }

    [Column(TypeName ="nvarchar(100)")]
    [DisplayName("Bank Name")]
    [Required(ErrorMessage = "This Field is required.")]
    public string BankName { get; set; }

    [Column(TypeName ="nvarchar(11)")]
    [DisplayName("SWIFT Code")]
    [Required(ErrorMessage = "This Field is required.")]
    [MaxLength(11)]
    public string SWIFTCode { get; set; }

    [DisplayName("Amount")]
    [Required(ErrorMessage = "This Field is required.")]
    public int Amount { get; set; }

    [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime Date { get; set; }
}

C#Copy

Here we’ve defined model properties for the transaction with proper validation. Now let’s define  DbContextclass for EF Core.

#asp.net core article #asp.net core #add loading spinner in asp.net core #asp.net core crud without reloading #asp.net core jquery ajax form #asp.net core modal dialog #asp.net core mvc crud using jquery ajax #asp.net core mvc with jquery and ajax #asp.net core popup window #bootstrap modal popup in asp.net core mvc. bootstrap modal popup in asp.net core #delete and viewall in asp.net core #jquery ajax - insert #jquery ajax form post #modal popup dialog in asp.net core #no direct access action method #update #validation in modal popup

Einar  Hintz

Einar Hintz

1602564619

MVC User Registration & Login with ASP.NET Core Identity

User registration and authentication are mandatory in any application when you have little concern about privacy. Hence all most all application development starts with an authentication module. In this article, we will discuss the quickest way to use **ASP.NET Core Identity for User Login and Registration **in a new or existing MVC application.

Sub-topics discussed :

  • How to add ASP.NET Core Identity to MVC application.
  • Customize ASP.NET Core Identity.
  • Identity.UI Design Customization.
  • Next step.

Background

ASP.NET Core Identity is an API, which provides both user interface(UI) and functions for user authentication, registration, authorization, etc. Modules/ APIs like this will really be helpful and fasten the development process. It comes with ASP.NET Core Framework and used in many applications before. Which makes the API more dependable and trustworthy.

ASP.NET Core MVC with user authentication can easily be accomplished using Identity.UI. While creating the MVC project, you just need to select Authentication as Individual User Accounts.

Showing how to create an MVC application with ASP.NET Core Identity API

The rest will be handled by ASP.NET Core Identity UI. It already contains razor view pages and backend codes for an authentication system. But that’s not what we want in most of the cases. we want to customize ASP.NET Core Identity as per our requirement. That’s what we do here.

Create an ASP.NET Core MVC Project

First of all, I will create a brand new ASP.NET Core MVC application without any authentication selected. We could add ASP.NET Core Identity later into the project.

In Visual Studio 2019, Go to File > New > Project (Ctrl + Shift + N). From new project window, select ASP.NET Core Web Application.

Create an ASP.NET Core Web application

Once you provide the project name and location. A new window will be opened as follows, Select _Web Application(Model-View-Controller), _uncheck _HTTPS Configuration _and DO NOT select any authentication method. Above steps will create a brand new ASP.NET Core MVC project.

Select Model View Controller templet under .NET Core

#asp.net core article #asp.net core #add asp.net core identity to existing project #asp.net core identity in mvc #asp.net core mvc login and registration #login and logout in asp.net core

AllowAnonymous in asp.net core

#Asp.net core #Asp.net core mvc #Core #Asp.net core tutorials #Asp.net core with entity framework

Authorization in asp.net core

#Asp.net core #Asp.net core mvc #Core #Asp.net core tutorials #Asp.net core with entity framework

Extend IdentityUser in ASP NET Core

#Asp.net core #Asp.net core mvc #Core #Asp.net core tutorials #Asp.net core with entity framework