In PCF we can set up the health check invocation timeout to execute X seconds after the instance has been created.  But before that, let's understand the PCF Health Check Lifecycle. Stage 1: The application is deployed to PCF Stage 2: When deploying the app, a health check type is specified and optionally a timeout. If a health check type is not specified, then the monitoring process defaults to a port health check Stage 3: Cloud Controller stages, starts, and runs the application Stage 4: Based on the type specified for the app, Cloud Controller configures a health check    that runs periodically for each app instance Stage 5: When Diego starts an app instance, the app health check runs every two seconds until a response indicates that the app instance is healthy or until the health check timeout elapses. The 2-seconds health check interval is not configurable Stage 6: When an app instance becomes healthy, its route is advertised, if applicable.                  Subsequent hea

Difference between OnActionExecting and OnActionExecutingAsync Both are ActionFilters can be added as attributes on Controller methods. OnActionExecting and OnActionExecutingAsync are both called before the controller action method is executed. The difference is OnActionExecuting runs SYNCHRONOUSLY and OnActionExecutingAsync should be used when you want to run some ASYNCHRONOUS calls. OnActionExecuting Implementation public class ActionFilter : Attribute, IActionFilter { private ILoggerEntry _loggerEntry; public ActionFilter(ILoggerEntry loggerEntry) { _loggerEntry = loggerEntry ?? throw new ArgumentNullException("ILogger cannot be null"); } public void OnActionExecuted(ActionExecutedContext actionContext) { _loggerEntry.AddToLog("Called after action method executes"); } public void OnActionExecuting(ActionExecutingContext actionContext) { _loggerEntry.A

You will get this issue when you try to call the BuildServiceProvider() from the Startup.ConfigureServices method. The recommended solution is to use the IApplicationBuilder ApplicationServices to get the registered services in IServiceCollection. Calling BuildServiceProvider anywhere in your code is bad design as this might create additional singleton instances of services. Each Service provider will have its own cache of singleton instances. If multiple service builders are created in code, it will cause the singleton instances to be created more than once, which contradicts the singleton property which is only once the instance is present throughout the lifetime of the application. Please find the alternative solution below, when you want to get the registered services for dependency injection. First, create a static class with a one property IServiceProvider type public void ConfigureServices(IServiceCollection services) { services.AddScoped<ILoggerEntry, LoggerEntry>();

.Net core supports dependency injection. There are many ways that you can inject services like constructor injection, action method injection, property injection. But there will be scenarios where you need to inject dependency services to static classes. For example, injecting services to extension methods. First, create a static class with a one property IServiceProvider type public void ConfigureServices(IServiceCollection services) { services.AddScoped<ILoggerEntry, LoggerEntry>(); services.AddTransient<IMongoRepository, MongoRepository>(); } Second, configure your services in ConfigureServices() method in Startup.cs and define the lifetime of the service instance using either Transient, Scoped or Singleton types. public void ConfigureServices(IServiceCollection services) { services.AddScoped<ILoggerEntry, LoggerEntry>(); services.AddTransient<IMongoRepository, MongoRepository>(); } For the next step to configure the Static class provider proper

How to clear visual studio cache Many times, during development you would face situations where project references are not loaded properly or you get missing/error DLL's. This is because the Component cache gets corrupted randomly and without any warnings. The first option that needs to be done is to clear component cache and restart Visual Studio since the Cache might be holding onto previous DLL versions. Here are the steps on how to clear Visual Studio Cache, Clearing Component Cache: Close all Visual Studio Instances running in your machine. Also, make sure devenv.exe is not running in the Task Manager Delete the Component cache directory - %USERPROFILE%\AppData\Local\Microsoft\VisualStudio\1x.0\ComponentModelCache Restart Visual Studio The above steps should fix the cache issue most of the times, but some times that is not enough and you need to perform the below steps as well. Clearing User's Temp Folder: Open the temp folder in this locatio n -  %USERPROFILE%\AppData\Loc

Error NU1605 - Detected package downgrade This error occurs when a dependency package has a version higher than an existing package version in the project solution. Solution: Add the following in .csproj file < PackageReference > < NoWarn >$( NoWarn ); NU1605 </ NoWarn > </ PackageReference > Another way to do this is to right-click on the solution and  click  Properties . Click  Build  and under  Errors and warnings  add 1605 to the  SuppressWarnings  text box. You can also add multiple error codes that you want to suppress by adding each separated by a comma. P.S. The below screenshot is in VS2019 Mac Version

PowerShell - REST API Many times we would require pulling web-based information into PowerShell. There are two ways to do that in PowerShell.  Invoke-WebRequest Invoke-RestMethod Invoke-WebRequest : This command can be used to get content from a web page. The cmdlet sends HTTP calls to a web page or a web server. Using Basic Authentication: $creds = [ System.Convert ]::ToBase64String([ System.Text.Encoding ]::UTF8.GetBytes( 'username:password' )) Invoke-WebRequest -URI '<path>' -Method 'POST' -ContentType 'application/json; charset=utf-8' -Headers @ { 'Accept' = 'application/json' ; 'Sample-Header' = 'Test' } -Authentication @ { 'Authorization' = 'Basic ' + $creds } Using a Client Certificate: Invoke-WebRequest -URI '<path>' -Method 'POST' -ContentType 'application/json; charset=utf-8' -Headers @ { 'Accept' = '

Senior .Net Developer Interview questions I have listed down some of the common .Net interview questions for Senior developer positions which will be helpful for someone who wants to brush up quickly before interviews. The topics that are covered are below, C#, OOPS, LINQ, ENTITY FRAMEWORK, SQL, .NET, DESIGN PATTERNS, ASP.NET, ASP.NET MVC, WCF, WEB API, REST, .NET CORE, JAVASCRIPT, JQUERY, ADO.NET, ANGULAR, ANGULAR JS, MONGO DB Explain SOLID Design principles in C#? Explain the 12-factor app methodology? Could you explain OWASP top 10 security risks and vulnerabilities? What are extension methods and how to define it? What is Dependency Injection(DI) and tools used for DI? Explain CLR in .Net and its functions? What is a .Net Web Service? What are generics and generic collections in C# and why we use it? What data types are applicable or can be passed in generics? What are dynamic types in C#? Please describe the use case? What is a strong-named assembly in .NET and what is t