Review of .Net Core 3

Some key features in .Net Core 3 / C# v8 Nullable Reference Types Pattern Matching Improvements First class support for Indices and Ranges Default Interface Members Async Streams JSON Parsing improvements Windows Desktop / Winforms Support Improvements to build, pack and deploy Nullable Reference Types The Null Reference Exception: static void NullException(MyObject obj) { Console.WriteLine(obj.title); […]

Azure Overview and App Service

Some general notes about the Azure cloud platform and services. Regions – geographical area with one or many datacenters Feature Availability – not all features available in every region Geography – discrete market area with one or more regions Availability Zones – physically separate locations within Region providing redundancy for that region Availability Sets – […]

AWS DAX Overview and Sample Application using Encryption At Rest

This is an overview with a sample application using AWS DAX – DynamoDB Accelerator. Further below is a sample application that uses DAX, DynamoDB and EC2 – all with encryption at rest. DAX is a fully managed, in-memory cache for DynamoDB. It reduces DynamoDB response times from milliseconds to microseconds. As with other AWS services, […]

.Net Core Services

This is a review of some of the core internals of the .Net Core Framework. Sample code can be found here: https://github.com/johnlee/dotnetcoreservices   Background NET was first announced by Microsoft in 2000 and then evolved from there. The .NET Framework has been the primary .NET implementation produced by Microsoft during that nearly two decade period. […]

Benchmarking AWS Databases

This was a quick app I created to run some basic tests against database services in AWS. It does basic read and writes using ADO.NET-ish frameworks. The dataset used is a 10 column varchar object called Item found in the mocks folder. The program can be run with different dataset sizes. Everything is configured through […]

Building .Net Core apps in Docker with VSCode on Mac or Windows

We can develop applications inside Docker containers and completely decouple our host machine from any SDK or development environments. This means that when using frameworks such as .Net Core, we no longer need to have it installed or running on the host machine. Instead, we get the .Net Core SDK docker image and develop within […]

.Net Core and Docker

These are some more notes about using .Net Core with Docker containers in a microservice architecture. A Docker container is just a process. It has a much smaller footprint than a virtual machine. VM includes the application, libraries, binaries and a full operating system. On the other hand, containers include the application and all libraries/binaries […]

Serverless Application using AWS Lambda, API Gateway and DynamoDB and NodeJS

This is small sample project that demonstrates a Serverless Application. It uses the following AWS Services: API Gateway Lambda DynamoDB The repository of this project can be found on github here: https://github.com/johnlee/habits   The application is used as a personal goal tracker. It stores daily attempts (with timestamps) and an overall score for the day. […]

.Net Core CLI

Some reference notes on using the dotnet cli and .net core.   Project templates can be created using the dotnet cli. As of v2.4.1 (sdk) the following are the template types. Note this can be seen with the ‘new’ command. lee@macbook:projects$ dotnet new Usage: new [options] Options: -h, –help Displays help for this command. -l, […]

.Net Core Dependency Injection

Dependency Injection (DI) is software design pattern that decouples (or loosely couples) components in an application. It is based on the Dependency Inversion Principle (DIP) which is part of a greater design principle of Inversion of Control (IOC). The components of an application, whether it be classes or modules, are instantiated at run-time – which […]

Introduction to ASP.NET Core

ASP NET Core Released June 2016 Build on .Net core Cross Platform Not tied to .Net framework Unification of MVC and Web API Dependency Injection is core feature (no third party) Modular HTTP Request pipeline Based on NuGet � everything is package Cloud ready IIS or self-host Open Source Problems with ASP NET MVC Dependency […]