Tuesday, May 18, 2021

Wednesday, May 5, 2021

Chat Application using Azure Web PubSub Service (Preview)

Azure Web PubSub service, as its name says, it is based on publish-subscribe pattern and enables us to build real-time web applications. 

Some of the popular examples where we can use this service is, for any chat-based applications, any collaboration application, like white boarding application. We can also use this service for any application which needs instant push notifications. In fact, there are many more example, we can think about. 

The best part is, we can use Azure Web PubSub service on all the platforms which supports WebSocket APIs and it allows up to 100 thousand concurrent connections at any point of time.

Components required to create a basic chat application:

  1. Instance of Azure Web PubSub Service
  2. Publisher application
  3. Subscriber application

To know about how to create and use these components, I’ve created a complete video demonstrating these: 

C# Code for Publisher and Subscriber:

Below is the C# code for the respective classes.

Publisher.cs

  1. var connectionString = "Your_ConnectionString_Here";  
  2. var hub = "Your_Hub_Here";  
  3. var serviceClient = new WebPubSubServiceClient(connectionString, hub);  
  4. while (true)  
  5. {  
  6.       Console.Write("Enter message: ");  
  7.       string message = Console.ReadLine();  
  8.       serviceClient.SendToAll(message);  
  9. }

Subscriber.cs

  1. var connectionString = "Your_ConnectionString_Here";  
  2. var hub = "Your_Hub_Here";  
  3.   
  4. // Either generate the URL or fetch it from server or fetch a temp one from the portal  
  5. var serviceClient = new WebPubSubServiceClient(connectionString, hub);  
  6. var url = serviceClient.GetClientAccessUri();  
  7.   
  8. using (var client = new WebsocketClient(url))  
  9. {  
  10.     client.MessageReceived.Subscribe(msg => Console.WriteLine($"Message received: {msg}"));  
  11.     await client.Start();  
  12.     Console.WriteLine("I'm connected.");  
  13.     Console.Read();  
  14. }  

Hope you enjoyed learning about Azure Web PubSub service.

Monday, May 3, 2021

401 vs 403 vs 409 - When to use What?

 This video explains the use of HTTP status codes 401, 403 and 409 along with an example.

Connecting Azure Account from Visual Studio Code

This video talks about how to connect to Microsoft Azure using Visual Studio Code and what all commands can be executed in order to interact with Azure.

Monday, April 19, 2021

How to Update Secret in GitHub Repository

This video explains the need of changing the deployment token, which gets generated while pushing our Azure Static Web App code on GitHub. It also talks about from where and how to get this token changed.

Sunday, April 18, 2021

CI/CD Setup with GitHub Repository using Visual Studio Code - Azure Static Web App

This video explains how to use Azure Static Web Apps (Preview) Extension to setup CI/CD with GitHub repository. It also explains about, how to push the code to GitHub, build and deploy it from VS Code.

Sunday, April 11, 2021

Visual Studio Code - Enable Spelling Checker

Recently, I’ve recorded a video which demonstrates how to get rid of typographic errors which we may have left while writing logic. As it is very usual that, while writing logic, sometimes we are in so hurry that we do not verify variable names or say class names. So, to help with all this, Visual Studio has an extension called Code Spell Checker. This video will throw some light on how to install this extension and how to use that. Have a look:

Sunday, April 4, 2021

Visual Studio Code - How to get started with C# project

Recently, I’ve recorded a video which demonstrates how to get started with C# development on Visual Studio Code. I provided a brief overview of this editor and also spoke about what all extensions are required to set up, in order to make developer’s life easy. One will also get to learn about how to create a solution file and a project from scratch using commands.

Tuesday, March 30, 2021

Redirecting Traffic Based On Priority Using Azure Traffic Manager

For any web application to work there has to be an associated end point, which means whenever users sends a request, endpoint is the first thing which gets hit. If I say in simple term, endpoint is an internet facing service which could be hosted either in Microsoft Azure or outside of Azure.

What is Azure Traffic Manager

Now what is Traffic Manager? As it’s name suggests, it manages the traffic. It distributes the traffic across various Azure regions along with health monitoring capabilities. So, if you are planning for a multi-region support with high availability, it could be a perfect service for you. 

Now, you must be thinking, what is the core which is making this happen? Actually it uses the DNS to route traffic to endpoints based on the selected Traffic Manger profile and the configured routing mechanisms. I’ll shortly mention about what all routing methods are available but before that let’s take a quick look at some of the major benefits which we can achieve using Traffic Manager. 

Benefits of using Azure Traffic Manager

  • Traffic Manager provides automatic failover whenever endpoint goes down as it keeps monitoring the end points.
  •  In case of planned maintenance activity, Traffic Manager redirects the traffic to other end points which are configured. So, we need not to worry about any downtime windows.
  • Traffic Manager has the ability to perform calculation to know which end point will provide lowest latency to the user. In a way, Traffic Manager improves the responsiveness by redirecting the traffic to such end points.
  • Another important capability of Traffic Manager is, it not only supports Azure end points, but it also go hand-in-hand with external non-Azure endpoints.
  • And lastly, Traffic Manager allows to combine multiple routing methods to achieve any complex business scenarios using nested profiling mechanism.

Ways to manage traffic

Currently, there are 6 ways once can manage DNS routing. 


Performance 

This method is useful, when endpoints are configured in different geographic locations and one wants to select the closet one, in terms of lowest network latency.


Weighted

In this method, one can create endpoints with designated weights, ranging between 1 and 1000 and based on the weight, traffic is redirected accordingly.


Geographical

This method route users based on the geo location or say, it works based on the geography their DNS query originates from. It may look similar to performance but actually it’s different. The best use case, I can think of is, let’s say due to some compliance and government regulations one wants all the traffic from EAST US to be redirected to WEST US endpoint. So, this can be achieved by selecting the geo based profile.


Priority

As it’s name says, it works on the basis of assigned priority. So, whichever endpoint is having higher priority, traffic would be redirected to that one. By any chance, if endpoint having highest priority is down or not healthy, request will automatically be redirected to the endpoint which is assigned as 2nd highest priority and it keeps going on. Such routing method is very useful in disaster recovery scenarios.


Multivalue

In this type of routing method, there exists multiple endpoints for a single client request. One caveat here is, one can not go with server name mappings and has to mandatorily go with IPv4 or IPv6 one. Unfortunately, I couldn’t find any real-time use case here.


Subnet

This method allows to map range of IP addresses to specific endpoints. Say, you want certain users or to be specific certain IP addresses to always use WEST US endpoint and rest all can use other end points then this routing method can be used.

Well enough of theory. Let’s have a look at practical example of how priority based DNS routing works.


Thursday, March 25, 2021

Enabling Preview Features in Visual Studio 2019

By default, Visual Studio doesn’t enable preview feature selection in Visual Studio 2019. Say you have .Net 5.0 installed on your machine and you are creating a new Console Application.

 After creating the application, you will notice that, although .Net 5.0 is installed, application still picks up the .Net Core 3.1 as a default framework. In fact, application didn’t ask for framework selection too.

So, how can we select the framework while creating an application itself. For doing this, we need to enable Preview Features in Visual Studio by going to Options menu as shown below:












Video of this feature can be found here.

Hope you enjoyed learning this cool tip.