The Tech Lab by Aisha Ikram

Load Balancer A load balancer allows you to evenly distribute traffic to multiple servers in one or datacentre. If a datacentre or server becomes unavailable (unhealthy) the load balancer will route the traffic to only available datacentres with servers.  Load Balancer is very important infrastructure component which runs in front of every service to mange and route traffic load. Load balancer is used for scalable and available solutions. Running your workload across multiple Availability Zones ensures that if I or 2  AZs become unavailable your service / applications remains available.  load balancer behind the scene manages all the traffic across regions and scaled solutions  For more information about scalability and availability read here High Scalability  and the  High Availability 

 High Availability  Your ability for your service to remain available by ensuring there is  *no single point Of failure and/or ensure a certain level of performance. High availability is achieved by replicating the images in multiple zones or data centres. So in case of any geo-disaster the alternative systems serve the users, hence it is called highly available. There are three types of redundancies: Local Redundancy Zone Redundancy Global/Geo Redundancy Local redundancy The default behaviour is locally replicating the data/resource images in multiple copies in the same datacentre. The resources by default have three copies. so if one copy fail to serve the other two are still available. This mode has less availability comparing to the other two but still it provides some piece of mind. Zones Redundancy  In this mode three copies of the resources are kept in three different zones or data centres in the same location/city. For example, UK West is a location which may...

Introduction: SOLID is short for 5 Design Patterns/ Principles (S-O-L-I-D) of Coding which are very commonly used in every software system. All the frameworks and existing solutions are based on these principles hence its very important to understand them before you even start designing or writing your piece of code. These are the guidelines to write clean code which is easy to maintain and extend without creating lots of bugs. S - Single Responsibility  O  - Open Closed Principle L - Liskov Substitution I  - Interface Segregation D - Dependency Inversion/Injection S- Single Responsibility This pattern states that every class/piece of code should have single responsibility and lots of tasks should not be aggregated into a single class. for example if a class Book stores information about a book, it should not be responsible about printing the book or logging information about it onto the console. we can divide the task of printing or logging into a separate class. For ex...

Data annotation can be used most commonly in in ASP.NET Core MVC or ASP.Net Data controls to perform model validation. Data annotations (available as part of the System. ComponentModel. DataAnnotations namespace, are attributes that can be applied to classes or class members to specify the relationship between classes, describe how the data is to be displayed in the UI, and specify validation rules. This article briefly tells you about data annotations, why they are useful, and how to use them in our .NET Core applications.  Types of Data Annotations  DA attributes are used to specify metadata on a class or a property. The data annotation attributes can broadly be classified into the following:   Validation attribute — Used to enforce validation rules on the properties of the entities  Display attribute — Used to specify how the data should be displayed in the user interface  Modeling attr...

Microsoft Azure is the second largest cloud technology to provide you various services.  In  order to understand the cloud, you need to understand the cloud basics or glossary. Here is the brief introduction and the major terminologies used in cloud Cloud Service Model Cloud systems offer three service models for your solution: ·          IAAS – Infrastructure As A Service -Infrastructure Provisioning/providing ·       PAAS – Platform As A Service - Dev/Deployment Environment provider ·       SAAS – Software As A Service- Web based Application provider    Cloud Deployment Model ·         Public ·         Hybrid ·         Private Cloud Architecture Terminologies  While dealing with Cloud offerings you will come across with these terminologies quite frequently, lets see what...

AZ-204 - Developing Solutions for Microsoft Azure      Exam Categories with %age of questions