Cloud Computing Scalability and Performance

Scalability, Performance, and Availability

Cloud Computing

• Scalability: Cloud computing allows for horizontal scaling (increasing/decreasing instances) and vertical scaling (increasing/decreasing instance size) to match changing workload demands.
• On-demand self-service: Cloud resources can be provisioned and de-provisioned automatically, without human intervention.
• Resource pooling: Cloud providers pool resources together to provide a multi-tenant environment, maximizing resource utilization.
• Rapid elasticity: Cloud resources can be quickly scaled up or down to match changing workload demands.

Load Balancing

• Definition: Load balancing is a technique to distribute incoming traffic across multiple servers to improve responsiveness, reliability, and scalability.
• Types of load balancing:
  • Hardware-based: Using a dedicated hardware device to balance traffic.
  • Software-based: Using software to balance traffic, often running on a virtual machine or container.
  • Cloud-based: Cloud providers offer load balancing services, often integrated with their infrastructure.
• Load balancing algorithms:
  • Round-robin: Each incoming request is sent to the next available server in a predetermined sequence.
  • Least connection: Incoming requests are sent to the server with the fewest active connections.
  • IP Hash: Each incoming request is directed to a server based on the client's IP address.

Failover Strategies

• Active-passive failover: One active server handles all requests, while a passive server waits in standby mode, ready to take over in case of failure.
• Active-active failover: Both servers are active and handle requests, with load balancing and synchronization mechanisms to ensure data consistency.
• N+1 redundancy: One or more redundant servers are added to a cluster, ensuring that the system remains operational even if one server fails.
• Failback: A failed server is repaired or replaced, and then returned to service, often with automated processes to ensure minimal downtime.

Cloud Computing

• Cloud computing allows for horizontal scaling, increasing or decreasing instances to match changing workload demands.
• Cloud computing allows for vertical scaling, increasing or decreasing instance size to match changing workload demands.
• Cloud resources can be provisioned and de-provisioned automatically through on-demand self-service, without human intervention.
• Cloud providers pool resources together to provide a multi-tenant environment, maximizing resource utilization through resource pooling.
• Cloud resources can be quickly scaled up or down to match changing workload demands through rapid elasticity.

Load Balancing

Definition and Types

• Load balancing is a technique to distribute incoming traffic across multiple servers to improve responsiveness, reliability, and scalability.
• Load balancing can be categorized into three types: hardware-based, software-based, and cloud-based.

Load Balancing Algorithms

• Round-robin algorithm: Each incoming request is sent to the next available server in a predetermined sequence.
• Least connection algorithm: Incoming requests are sent to the server with the fewest active connections.
• IP Hash algorithm: Each incoming request is directed to a server based on the client's IP address.

Failover Strategies

Failover Techniques

• Active-passive failover: One active server handles all requests, while a passive server waits in standby mode, ready to take over in case of failure.
• Active-active failover: Both servers are active and handle requests, with load balancing and synchronization mechanisms to ensure data consistency.

Redundancy Strategies

• N+1 redundancy: One or more redundant servers are added to a cluster, ensuring that the system remains operational even if one server fails.
• Failback: A failed server is repaired or replaced, and then returned to service, often with automated processes to ensure minimal downtime.

Cloud Computing

• Cloud computing resources can be scaled up or down quickly to match changing business needs.
• Resources can be provisioned and de-provisioned automatically without human intervention through on-demand self-service.
• Multiple customers share the same infrastructure, reducing costs and improving utilization, which is known as multi-tenancy.
• Cloud computing resources can be quickly scaled up or down to match changing business needs, which is known as rapid elasticity.

Load Balancing

Distribution of Workload

• Incoming traffic is distributed across multiple servers to improve responsiveness and reliability.
• There are three types of load balancing:
  • Hardware-based: Dedicated hardware devices distribute traffic.
  • Software-based: Software applications distribute traffic.
  • Cloud-based: Cloud providers offer load balancing as a service.

Load Balancing Algorithms

• There are three load balancing algorithms:
  • Round Robin: Each server is used in sequence.
  • Least Connection: Traffic is directed to the server with the fewest connections.
  • IP Hash: Each client is directed to a specific server based on their IP address.

Scaling

Types of Scaling

• There are two types of scaling:
  • Horizontal scaling (Scaling out): Adding more servers to distribute the workload and increase processing power.
  • Vertical scaling (Scaling up): Upgrading individual servers to increase processing power.

Scaling Methods

• There are two scaling methods:
  • Manual scaling: Scaling is performed manually by administrators.
  • Auto-scaling: Scaling is performed automatically based on predefined rules and metrics.