a developer's notebook
C# 7.0 adds a number of new features and brings the focus on data consumption, code simplification and performance. Perhaps the most interesting feature is tuples, a finite ordered list of values, of possibly different types, which is used to bundle related values together without having to create a specific type to hold them. Tuples are very good for performance reasons, as you don’t…
Build 2017 is over. A three-day conference, where a lot of great stuff was announced. Apart from the keynotes of every day, there are many technical sessions to watch and learn from. The whole list of sessions is available at Channel 9. Here you may find my picks from the categories I am interested in. Azure Related Visual Studio &…
When starting playing with Service Fabric in Visual Studio, you may come to the following error when trying to debug your application:
1 2 3 4 | System.Fabric.FabricConnectionDeniedException: 'Not authorized to connect' Inner Exception COMException: Exception from HRESULT: 0x80071C43 |
The error although may look tricky, is very easy to fix and happens when you have created a Service Fabric application and accidentally Set as Startup Project the Fabric Service, as showing in the following picture: So, Set as Startup Project the Service Fabric…
A great tool, when starting learning Elixir, is Elixir’s Interactive Shell (IEx), which allows you to type any Elixir expression and get its result. To start using IEx, open a terminal of your choice and type iex (or iex.bat if you are on Windows), which stands for Interactive Elixir. By default, colors are not enabled and iex looks like what you see below: It turns out…
To keep things tidy, in case you have multiple subscriptions associated with your Azure account, it’s a good practice to name them in a way that makes sense to you. For example, if you have an msdn subscription, the default name in Azure Portal is “Visual Studio Enterprise“, or if you have applied for a Visual Studio Dev Essentials program, the default name is “Developer Program…
Azure App service provides an easy way to track your web app’s availability / health and to get details on when and why your app wasn’t available. This kind of info is available through the web app’s blade, when selecting Diagnose and solve problems A new page appears with details on: app’s availability; requests per 5 minutes; and when and why your app…
IEx is Elixir’s interactive shell, where you can type any Elixir expressions and get its result. One issue you might come across when trying to use iex in Powershell, through a command e.g. iex -S mix, you might get the following error:
1 2 3 4 5 6 | Invoke-Expression : A parameter cannot be found that matches parameter name 'S'. At line:1 char:5 + iex -S mix + ~~ + CategoryInfo : InvalidArgument: (:) [Invoke-Expression], ParameterBindingException + FullyQualifiedErrorId : NamedParameterNotFound,Microsoft.PowerShell.Commands.InvokeExpressionCommand |
The problem is that iex is an alias in Powershell, for Invoke-Expression
1 2 3 4 5 | PS C:\Workspace> Get-Command iex CommandType Name Version Source ----------- ---- ------- ------ Alias iex -> Invoke-Expression |
Solution To overcome this problem you simply use iex.bat…
Some really easy ways to improve performance in your asp.net core web application are: response caching, which adds cache-related headers to responses, to reduce the number of requests a client makes to your web server; compressing response using gzip to reduce its size. You may start with the default asp.net core web application, apply the above steps and check the result. Setup…
Sometimes, the response from a request is required first in order to continue with all the other API requests currently stored in your Postman folders. Think of a request that, in order to return results, it requires from you to be authenticated, so a typical workflow would be: authenticate yourself with a proper username and password; get an authentication token; update…
In Entity Framework code-first, if you have a domain model like the following:
1 2 3 4 5 6 7 | public class Country { public int Id { get; set; } [Index] public string IsoCode { get; set; } } |
and want to create an index for a string property, when you execute update-database for your migration, you may end up with the following error: This usually happens when you use VARCHAR(max), which is the default column type when creating a string property in EF. To make…
