Fundamentals of cloud based systems

Fundamentals of Cloud-Based Systems

Cloud computing enables organizations, such as companies in a supply chain, to share computing resources, access advanced systems, and reduce the cost of owning and maintaining their own infrastructure.

What cloud computing is

Cloud computing provides computing resources, software, and information as services over a network. Instead of owning the underlying products or equipment, users access a shared pool of configurable resources on demand.

Main characteristics

• Remote and network-accessible: Services and data are hosted remotely and can generally be accessed from anywhere with an internet connection.
• Pay-per-use: Users pay according to the resources or services they consume.
• Resource pooling: Providers share computing capacity among multiple users or organizations, making more efficient use of resources.
• Rapid elasticity: Capacity can be increased or reduced quickly as needs change.
• Measurable and controllable use: Resource consumption can be monitored and managed, allowing providers to charge based on usage.

Cloud service models

Infrastructure as a Service (IaaS)

IaaS provides computing resources such as processing power, storage, and servers. Virtualization divides a provider’s physical resources among users, who rent infrastructure instead of purchasing and maintaining their own hardware. Capacity can be scaled to meet processing and storage needs.

Example: Amazon Web Services

Platform as a Service (PaaS)

PaaS provides an environment for developing, managing, testing, and deploying applications. The provider supplies infrastructure along with tools and system software, such as an operating system and development tools. This lets users focus on application development rather than managing the underlying infrastructure.

The provider is responsible for tasks such as platform maintenance, software updates, security, and backups. Shared platforms can also support collaboration among remote teams.

Examples: Windows Azure and Google App Engine

Software as a Service (SaaS)

SaaS provides access to complete, provider-hosted applications over the internet or through an API. Users typically subscribe to the software and do not need to install, update, or manage it themselves. Applications can be accessed from internet-connected devices in different locations.

Examples: Salesforce CRM and Lotus Live

These models can be understood as layers: IaaS provides computing resources, PaaS adds an application-development environment, and SaaS delivers finished applications.

Cloud deployment models

• Private cloud: Used by a single organization. It may be managed internally or by a third party and hosted within or outside the organization.
• Community cloud: Shared by a defined group of organizations with common interests, such as an industry consortium or a company and its suppliers and partners.
• Public cloud: Offered by a provider for use by the general public or a broad range of customers.
• Hybrid cloud: Combines two or more clouds connected through standard or proprietary technology.

Advantages

• Reduces the need to buy and maintain expensive computing equipment.
• Provides access to powerful infrastructure that may be unaffordable for an individual organization to own.
• Allows capacity to scale with demand.
• Can provide high performance through professionally maintained infrastructure.
• Avoids the need for each user to purchase and manage expensive software.
• Makes software updates and patches easier to distribute centrally.
• Supports broad storage capacity, access to documents from different locations, and collaboration among distributed users.
• Can improve consistency in document formats and access to the latest shared version.
• Provider-managed data may be more reliable, although cloud data can still be lost or damaged.

Concerns and disadvantages

• Dependence on providers: Relying on an outside company can limit an organization’s flexibility and innovation. A small number of providers could also come to dominate the market.
• Security, privacy, and ownership: Users may not know exactly where their data is stored, who can access it, or how ownership and privacy are protected.
• Jurisdiction and policy: Data stored in another country may be subject to different laws or policies.
• Provider or infrastructure failure: A major attack or failure affecting a provider or data center could disrupt access or lead to data loss.
• Account and access problems: Users may be unable to reach their data if they are locked out of an account or cannot connect to the service.
• Internet dependence: Cloud services require a usable internet connection; limited connectivity can make them unavailable or slow.
• Limited customization: Users may be restricted to the features offered by the provider.
• Performance constraints: Slow networks or devices can make cloud applications sluggish.
• Complex or demanding workloads: It remains unclear how some resource-intensive and high-performance computing tasks should be handled in the cloud.
• Standards and compatibility: Different protocols, databases, and vendor-specific requirements can create interoperability issues.

Speakers and sources

• Speaker: One lecturer or presenter speaks throughout the video.
• Sources and services named as examples: Amazon Web Services, Windows Azure, Google App Engine, Salesforce CRM, Lotus Live, Google Docs, Google, and IBM.