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Introduction to Cloud Computing

Cloud Computing refers to both the application delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services.

Cloud Computing

  • Scalability/elasticity - infinite virtual resources;
    • Scale up - increase the resources of a single node;
    • Scale down - increase the number of nodes;
    • Workloads - the amount of work performed by a computer system;
  • Pay-per-use - utility prices;
  • Self-service interfaces;
  • Virtualization - avoid acquisition/installation/maintenance of datacenters.

Cloud Computing is the storing, processing and use of data on remotely located computers accessed over the internet.

There are multiple execution environments:

  • Virtual machines;
  • Containers;
  • Web applications;
  • Serverless;
  • Databases.

Energy is a relevant cost for the provider:

Power Usage Efficiency = Total Facility Energy / IT Equipment Energy

Auto Scaling

  • Scale up and scale down;
  • Algorithms to control and allocate resources with loads - workloads;
  • Requires the computation and data distribution through multiple nodes;
  • Coordination between nodes is critical.

Cloud Computing Models

  • Private Cloud - exclusive to an organization;
  • Community Cloud - exclusive to a consumer community that share the same goals;
  • Public Cloud - belongs to a provider, with multiple processing centers located in different countries; the consumers access the cloud using pay-per-use models, with different service layers (SLA - Service Level Agreement);
  • Hybrid Cloud - combination of two or more clouds, that operate through models and technologies that facilitate the data and application portability.

Cloud Computing Stack

Service Class Access & Tools Service Contents
SaaS (Software as a Service) Web Browser Cloud Applications (social networks, email, ...)
PaaS (Platform as a Service) Development Environments Cloud Platform (programming languages, frameworks, Web APIs, ...)
IaaS (Infrastructure as a Service) Virtualization Manager Cloud Infrastructure (computer servers, data storage, firewall, load balancer, VPN, ...)

Cloud Computing Stack

Cloudnomics: CAPEX vs. OPEX

Total Cost of Ownership (TCO):

  • CAPEX - Capital Expenditure: expenses that create future benefits; buy fixed assets; initial investment; significant cost;
  • OPEX - Operational Expenditure: continuous/daily cost of the product/system execution.

Opportunities

  • Pay-per-use - pay only for what you use;
  • Elasticity - infinite resources;
  • Self-service interfaces;
  • Avoids the acquisition, installation and maintenance of datacenters.

Challenges

  • Avoid vendor lock-in - the interoperability between providers is very hard/inexistent;
  • Uncertainty about physical control of the hardware, software and data;
  • Migrate applications to public clouds is a complex process;
  • Security and privacy issues;
  • Uncertainty about legal issues;
  • Difficulty in defining SLAs (Service Level Agreement);
  • Lack of standards and interoperability between providers;
  • Multi-tenancy - multiple users share the same resources;
  • A dead Internet connection means no work - the Internet is the only way to access the cloud.

SWOT

Cloud Services Examples

  • Massive data storage: Amazon S3, Azure Storage, Google Cloud Storage;
  • VM creation: Amazon EC2, Azure VM, Google Compute Engine;
  • NoSQL data storage: Amazon DynamoDB, Azure CosmosDB, Google Firestore;
  • Messages: Azure Queues, Google Pub/Sub;
  • Data analytics: Google MapReduce, TensorFlow.

The top 3 Cloud Service Providers are:

  • AWS - Amazon Web Services
  • Microsoft Azure
  • GCP - Google Cloud Platform (used in this course)

Cloud Service Providers