Cloud Computing Models
Learn the fundamental service models that define how cloud resources are delivered and consumed.
IaaS
PaaS
SaaS
Cloud computing is delivered through three primary service models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Each model provides different levels of control and management responsibility.
# Cloud Service Models
cloud_service_models = {
"iaas": {
"description": "Infrastructure as a Service",
"provides": ["Virtual machines", "Storage", "Networks", "Load balancers"],
"customer_manages": ["OS", "Runtime", "Applications", "Data"],
"provider_manages": ["Physical infrastructure", "Virtualization", "Networking"],
"examples": {
"aws": "EC2, VPC, EBS",
"gcp": "Compute Engine, VPC, Persistent Disks"
},
"use_cases": ["Custom applications", "Legacy migrations", "Development environments"]
},
"paas": {
"description": "Platform as a Service",
"provides": ["Development platform", "Runtime environment", "Database", "Web server"],
"customer_manages": ["Applications", "Data", "Configuration"],
"provider_manages": ["OS", "Runtime", "Infrastructure"],
"examples": {
"aws": "Elastic Beanstalk, Lambda",
"gcp": "App Engine, Cloud Functions"
},
"use_cases": ["Web applications", "API development", "Microservices"]
},
"saas": {
"description": "Software as a Service",
"provides": ["Complete applications", "User interface", "Data storage"],
"customer_manages": ["User data", "Access controls", "Configuration"],
"provider_manages": ["Everything else"],
"examples": ["Gmail", "Office 365", "Salesforce", "Slack"],
"use_cases": ["Email", "CRM", "Collaboration", "Analytics"]
}
}
Public vs Private Cloud
Understand different cloud deployment models and their appropriate use cases.
Cloud Deployment Models:
• Public Cloud: Multi-tenant, shared infrastructure, cost-effective
• Private Cloud: Dedicated infrastructure, enhanced security and control
• Hybrid Cloud: Combination of public and private clouds
• Community Cloud: Shared among organizations with common requirements
• Multi-Cloud: Using multiple cloud providers simultaneously
Deployment Decision Factors:
Choose deployment models based on security requirements, compliance needs, cost constraints, performance requirements, and existing infrastructure investments.
# Cloud Deployment Models
deployment_models = {
"public_cloud": {
"characteristics": ["Shared infrastructure", "Internet accessible", "Pay-per-use"],
"advantages": ["Lower costs", "Scalability", "No maintenance", "Global reach"],
"disadvantages": ["Less control", "Security concerns", "Compliance limitations"],
"best_for": ["Startups", "Variable workloads", "Development/testing", "Web applications"]
},
"private_cloud": {
"characteristics": ["Dedicated infrastructure", "Enhanced security", "Full control"],
"advantages": ["Security", "Compliance", "Customization", "Performance"],
"disadvantages": ["Higher costs", "Maintenance overhead", "Limited scalability"],
"best_for": ["Regulated industries", "Sensitive data", "Consistent workloads"]
},
"hybrid_cloud": {
"characteristics": ["Combines public and private", "Data/workload portability"],
"advantages": ["Flexibility", "Cost optimization", "Compliance", "Scalability"],
"challenges": ["Complexity", "Integration", "Management", "Security"],
"use_cases": ["Burst to cloud", "Data sensitivity", "Regulatory compliance"]
}
}
Shared Responsibility Model
Understand the division of security and operational responsibilities between cloud providers and customers.
Provider Responsibilities:
• Physical security of data centers
• Infrastructure and network controls
• Host operating system patching
• Hypervisor security
• Service availability and durability
Customer Responsibilities:
• Data classification and protection
• Identity and access management
• Application-level controls
• Operating system updates
• Network traffic