Introduction to Cloud Computing

Introduction to Cloud Computing

• Cloud computing is a model for delivering IT resources (networks, servers, storage, applications, & services) on demand over the internet.
• NIST defines five essential characteristics, three service models, and four deployment models for cloud computing.
• A cloud is a collection of networked IT resources (shared hardware and software) deployed in data centers.

The Roots of Cloud Computing

• Cloud computing evolved from advancements in hardware (virtualization, multi-core chips), internet technologies (Web services, SOA, Web2.0), distributed computing (clusters, grids), and systems management (autonomic computing, data center automation).
• Utility computing is a concept of delivering on-demand access to shared resources (infrastructure, applications, and business processes) over the internet for a fee.
• Mainframe computers were replaced by commodity servers, driving the shift to distributed data centers and enabling resource sharing over vast distances.
• Service-oriented architectures (SOA) and Web services enabled applications to communicate and share information over the internet using standards like HTTP and XML.
• Grid computing involves distributed systems with non-interactive workloads utilizing numerous files. It differs from cluster computing in that each node performs a different task. Grid computers are geographically dispersed and heterogeneous.
• Virtualization enables running multiple operating systems and software stacks on a single physical platform. A virtual machine monitor (VMM) mediates access to hardware, presenting each guest operating system with a virtual machine (VM).

Essential Cloud Characteristics

• On-demand self-service: Users can access resources independently without requiring interaction with service providers.
• Broad network access: Cloud services can be accessed from diverse devices and locations via the internet.
• Resource pooling: Cloud providers pool shared resources (servers, storage, etc.) to serve multiple users.
• Rapid elasticity: Cloud resources can be dynamically scaled up or down based on demand. This "elasticity" is a key feature of cloud computing.
• Measured services: Resource usage is metered and users are charged based on consumption - a "pay-as-you-go" principle.

Cloud Computing Characteristics

• Cloud computing provides on-demand, scalable, and elastic computing and storage services.
• Cloud services operate on a shared resource pool using the internet to offer scalability and elasticity.
• Elastic computing allows for dynamic resource acquisition and adaptation to variable workloads.
• Resource metering and usage-based payment models are central to cloud computing.

Cloud Computing Advantages:

• Lower computer costs due to shared resources.
• Improved performance through resource multiplexing, enabling higher utilization during peak demands.
• Reduced software costs due to shared applications and cloud-based services.
• Instant software updates and improved document format compatibility through cloud-based services.
• Unlimited storage capacity provided by cloud providers.
• Increased data reliability through distributed data storage and backup mechanisms.
• Universal document access from any device.
• Easier group collaboration with shared cloud-based documents and tools.
• Device independence for accessing cloud services.

Cloud Computing Disadvantages:

• Requires a constant internet connection.
• Can be slow with low-speed internet connections.
• Features might be limited compared to desktop software.
• Data security concerns exist as data is stored remotely on third-party servers.
• Data loss risk may exist due to failures or security breaches in the cloud infrastructure.

Cloud Computing Challenges:

• Service availability concerns: Ensuring continuous service delivery despite potential outages or failures.
• Data confidentiality and auditability: Maintaining data privacy and integrity in the cloud environment.
• Diversity of services and user interfaces across providers: Difficulty in switching between services and achieving seamless data transfer.
• Data transfer bottlenecks: Challenges in handling intensive data transfers over the internet.
• Performance unpredictability: Resource sharing can lead to unpredictable performance variations.
• Ensuring QoS guarantees: Utilizing resource virtualization and performance isolation to meet user demands.
• Resource management: Managing diverse workloads in large data centers efficiently, potentially using self-organization and self-management approaches.

Infrastructure as a Service (IaaS)

• IaaS provides access to compute resources (CPU, VMs, storage) where users can deploy and run arbitrary software, including operating systems and applications.
• Users maintain control over operating systems, storage, and applications, but have limited management over the underlying infrastructure.
• IaaS services include server hosting, storage, virtual instances, load balancing, internet access, and bandwidth provisioning.
• An example of IaaS is Amazon EC2.

Database as a Service (DBaaS)

• DBaaS is a cloud service offering access to databases without physical hardware setup, software installation, or configuration.
• Administration and maintenance tasks are handled by the service provider.
• DBaaS uses a layered architecture: user interface layer, application layer, database layer, and data storage layer.
• Examples of DBaaS include SAP HANA Cloud, Oracle Database, Amazon RDS, and Azure SQL Database.

Why Cloud Computing is Successful

• Cloud providers have benefited from advancements in software, networking, storage, and processor technologies.
• The economic impact of cloud computing is vast, driving adoption in enterprises, institutions, and organizations.
• Cloud infrastructures are mostly homogeneous, simplifying security, resource management, fault tolerance, and quality of service compared to heterogeneous environments.
• The pay-as-you-go model eliminates upfront financial commitments, attracting new applications and users.

This quiz covers the fundamentals of cloud computing, including its essential characteristics, service models, and deployment strategies. Explore how cloud computing evolved from earlier technologies and the significance of utility computing in today’s IT landscape.