What Is Load Balancing

 What Is Load Balancing?

Load balancing is the process of distributing network traffic across multiple servers. This ensures no single server bears too much demand. By spreading the work evenly, load balancing improves application responsiveness. It also increases availability of applications and websites for users. Modern applications cannot run without load balancers.

A load balancer acts as the “traffic cop” sitting in front of your servers and routing client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance. If a single server goes down, the load balancer redirects traffic to the remaining online servers. When a new server is added to the server group, the load balancer automatically starts to send requests to it.

In this manner, a load balancer performs the following functions:

1. Distributes client requests or network load efficiently across multiple servers
2. Ensures high availability and reliability by sending requests only to servers that are online
3. Provides the flexibility to add or subtract servers as demand dictates

Question: There is a website run by 2 servers. These 2 servers balances the load using Load Balancer. So, if 1 session is created on 1 server and say load is shift to another server immediately, then how session is maintained?

This is where the concept of "Sticky Sessions" or "Session Affinity" comes into play.

Sticky Sessions: By default, a Classic Load Balancer routes each request independently to the registered instance with the smallest load. However, you can use the sticky session feature (also known as session affinity), which enables the load balancer to bind a user's session to a specific instance. This ensures that all requests from the user during the session are sent to the same instance. Read more

In .Net there are two concepts called StateServer or SQLServer which are the recommendations to get the session information out of the execution process in the servers, so that's the idea, isolate the sessions in a different server or process, you can read a little bit here:

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Windows Azure and Cloud Computing - A Glance

Windows Azure, which was later renamed as Microsoft Azure in 2014, is a cloud computing platform, designed by Microsoft to successfully build, deploy, and manage applications and services through a global network of datacenters. 

The popular trend in today's technology driven world is ‘Cloud Computing’. Cloud computing can be referred to as the storing and accessing of data over the internet rather than your computer's hard drive.

One prominent example of cloud computing is Office 365 which allows users to store, access, edit their MS Office documents online (in browser) without installing the actual program on their device.

Types of Cloud

The storage options on cloud is in 3 forms −

• Public
• Private
• Hybrid

    Public Cloud − A service provider makes the clouds available to the general public which is termed as a public cloud. These clouds are accessed through internet by users. These are open to public and their infrastructure is owned and operated by service providers as in case of Google and Microsoft.

         Private Cloud − These clouds are dedicated to a particular organization. That particular organization can use the cloud for storing the company's data, hosting business application, etc. The data stored on private cloud can't be shared with other organizations. The cloud is managed either by the organization itself or by the third party.

         Hybrid Cloud − When two or more clouds are bound together to offer the advantage of both public and private clouds, they are termed as Hybrid Cloud. Organizations can use private clouds for sensitive application, while public clouds for non-sensitive applications. The hybrid clouds provide flexible, scalable and cost-effective solutions to the organizations.

Benefits of Cloud

There are many benefits of clouds. Some of them are listed below.

·     Cloud service offers scalability. Allocation and de-allocation of resources is dynamically as per demand.

·    It saves on cost by reducing capital infrastructure.

·    It allows the user to access the application independent of their location and hardware configuration.

· It simplifies the network and lets the client access the application without buying license for individual machine.

·   Storing data on clouds is more reliable as it is not lost easily.

What are IaaS, PaaS and SaaS?

Generally, cloud computing services fall into these three broad categories:

1. IaaS
2. PaaS
3. SaaS

IaaS (Infrastructure as a Service)

IaaS is the most basic level of cloud-based solutions, which refers to renting an IT infrastructure as a fully outsourced service. In this category, the cloud provider lets you rent servers, VMs, storage, network and operating systems on a pay-as-you-go basis.

Examples:

Amazon EC2 and S3, Google Compute Engine, Windows Azure.

PaaS (Platform as a Service)

PaaS is the cloud solution where, apart from providing an infrastructure, cloud providers also issue an on-demand computing environment to develop, test, run and collaborate with components such as web servers, database management systems, and software development kits (SDKs) for various programming languages.

Examples:

AWS Elastic Beanstalk, Heroku, Windows Azure, Force.com, Google App Engine.

SaaS (Software as a Service)

SaaS providers offer fully functional web-based application softwares tailored to a variety of business needs such as project tracking, web conferencing, marketing automation or business analytics.

Examples:

Google Apps, Microsoft Office 365, Gmail, Yahoo and Facebook.

These three different types of cloud computing services also offer different amounts of convenience and different amounts of control to the user. In that regard, they stack up as such:

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