Day 1: 𝐋𝐨𝐚𝐝 𝐁𝐚𝐥𝐚𝐧𝐜𝐞𝐫 & 𝐀𝐮𝐭𝐨 𝐒𝐜𝐚𝐥𝐢𝐧𝐠 𝐆𝐫𝐨𝐮𝐩:

Scalability:

• Vertical Scalability: Also known as “scaling up,” it involves adding more resources (CPU, RAM, etc.) to an existing server or instance to handle increased loads.
• Horizontal Scalability: Also known as “scaling out,” it involves adding more servers or instances to a system to distribute the load and handle increased traffic.

High Availability:

• High Availability ensures that your application remains operational with minimal downtime by eliminating single points of failure.
• It often involves redundancy, failover mechanisms, and load balancing to distribute traffic across multiple servers or data centers.

Elastic Load Balancer:

• An Elastic Load Balancer is a service that automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses.
• It helps enhance the availability and fault tolerance of your application.

Types of Load Balancers:

• Application Load Balancer: Operates at the application layer (Layer 7) and is ideal for routing HTTP/HTTPS traffic. It supports content-based routing, host-based routing, and path-based routing.
• Network Load Balancer: Operates at the transport layer (Layer 4) and is designed for handling TCP/UDP traffic. It is suitable for applications that require high performance and low latency.
• Gateway Load Balancer: Used to route traffic to virtual appliances, such as firewalls and intrusion detection systems. It’s often used in more complex network architectures.

Target Groups:

• Sticky Sessions: Also known as session affinity, it ensures that a user’s requests are always routed to the same target in a target group, which can be useful for applications that require stateful connections.
• SSL/TLS Certificates: You can configure SSL/TLS certificates at the load balancer level to secure the traffic between clients and your application.
• Server Name Indication: SNI allows the load balancer to route traffic to the appropriate backend server based on the hostname requested by the client, which is especially useful for hosting multiple SSL/TLS-secured sites on the same load balancer.
• Connection Draining (Deregistration Delay): This feature ensures that active connections to instances are completed before they are removed from the load balancer, preventing abrupt disruptions when instances are taken out of service.

Auto Scaling Group:

• An Auto Scaling Group allows you to automatically adjust the number of instances in your application based on defined policies.
• CloudWatch Alarms can trigger scaling actions based on metrics and thresholds.
• Scaling Cooldowns can be set to prevent rapid scaling in and out, helping to stabilize the environment.

These are some key points related to each of the headings you mentioned. For more detailed information, it’s a good idea to refer to Amazon Web Services (AWS) documentation or the documentation of the specific cloud service provider you’re using.