Types of Cloud

Public : AWS, GCE, MS Azure, Alibaba cloud, IBM cloud, Flexible engine by Orange
Private : in-premises cloud using vmware, Openstack
Hybrid : Public + Private clouds
Multicloud : Combination of different cloud offers

What is the need of Cloud computing ?

Need of Cloud computing

1. Globalization

to serve customer 24X7 across the globe

2. Aging Data centers

Migration and upgrade to new technologies

3. Storage growth

Explosion of storage consumption and usage

4. Application growth

Need of new application deployment rapidly

5. Cost of ownership

Cost of buying new equipments, power, cooling support, licences increases Total Cost of Ownership (TCO)

6. Acquisitions

When companies are acquired, it may be hard to make both IT infra interoperable

Requirements of Cloud infrastructure

Requirements of Cloud infrastructure

1. On-demand and self-service

Provide access as and when required, without any human intervention

2. Broad network access

Accessed through internet from wide number of devices

3. Resource pooling

Maintain resource pool to meet the requirements

4. Rapid elasticity

Ability to expand / reduce allocated IT resources

5. Metered service

Provide charging and billing of usage to consumers

What are Classic Datacenter components ?

Components of Classic Datacenter (CDC)

1. Application
• Business app - email, ERP, DSS, DW
• Management app - HRMS, PIMS
• Data protection - Replication, Backup
• Security app - Antivirus, Authentication
2. Compute - runs application
• Physical components - CPU, Memory (RAM, ROM), I/O devices
• Logical components - OS, File system, Volume manager, Device drivers
3. DBMS
4. Storage
• Tape drive, Optocal disk, Disk drives, Solid state drives
5. Network - Data path to communicate

What type of virtualization a VDC datacenter provides ?

VDC is a datacenter where compute, storage, network, applications are virtualized.

Compute virtualization

Running multiple OS concurrently on a compute system

Storage virtualization

Providing logical view of storage and present to the compute system

Network virtualization

Creation of multiple logical networks on a physical network

How datacenter components communicates to each other ?

Communication between datacenter components

Compute to Compute communication

1. NIC (Network inteface card) 

    Connects compute system to network. Each NIC has unique MAC address.

2. Interconnect devices

    Router - Device or software which determines next network point to send the packet

    Switch - Allows communication between nodes of a network

3. Cables

     Twisted pair, Co-axial cables, Optical fiber etc.

Compute to Storage communication

1. HBA (Host bus adaptor)

    An IC board performed I/O interface functions between host and storage

2. CNA (Converged network adaptor)

    Consolidates functionality of NIC card and Fiber Channel HBA into single adaptor

3. NIC (Network inteface card) 

4. Interconnect devices

5. Ports / Cables

Compute to Storage communication - protocols

1. PCI (Peripheral Component interconnect)

    Standard for info exchange between CPU and Network card / Modem.

    PCI bus can be of 32 or 64 bits.

2. IDE (Integrated Device Electronics) / ATA (Advanced Technology Attachement)

    Protocol to connect storage devices - HDD, CD-ROM

     a. Parellel ATA (PATA) or ATA supports 16 bit parallel transfer

     b. Serial ATA (SATA) supports a single-bit serial transmission 
3. SCSI (Small Computer System Interface)

    A parallel transmission protocol preferred in high-end computers.

    It provides improved performance, scalability, and compatibility compared to ATA.

4. TCP / IP

Compute to Storage communication - Network technology protocols

1. Fiber Channel (FC)

    Commonly used in SAN in enterprise storage

    Port types : N_port, E_port, F_port, G_port

    Addressing types : Fibre Channel address , WWN name

2. iSCSI (SCSI over IP)

    Encapsulation of SCSI I/O over IP

3. FCIP (Fiber Channel over IP)

    IP based storage networking technology that combines advantages of fibre channel & IP.

4. FCoE (Fiber Channel over Ethernet)

    Encapsulation of fiber channel frames for transport over enhanced Ethernet networks.

    Main components are : CNA, FCoE switch, Conventional enhanced Ethernet.

What are deployment model of Cloud ?

Public Cloud

• Provider makes IT resources (applications, storage capacity, or compute) available to any consumer
• "on-demand” and “pay-as-you-go” environment 

Private Cloud

• operated solely for one organization and not shared with other organizations
• offers the greatest level of security and control.
• Two variations : On-premise and Externally-hosted private cloud

Hybrid Cloud

• Organization consumes resources from both private and public Clouds.
• uses their computing resources on a private Cloud for normal usage, but access the public Cloud for high/peak load requirements

Community Cloud

• Cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns
• Community Cloud is managed by Organization or third party

How to decide suitable Cloud model for your organization ?

Individual - Public Cloud

• Convenient Outweighs Risk
• Free or Low cost
• Example: Picasa, Google drive

Startups - Public Cloud

• Convenient Outweighs Risk
• No CAPEX and OPEX
• Self service
• Back-office, Dev and Prod

Small/Medium Business - Hybrid Cloud (Public + Private)

• Tier 1 apps : Private cloud
• Tier 2-4 apps : Public cloud for backup, Archieve, Testing , Non OLTP apps

Enterprise - Public Cloud

• Tier 2-4 : Private cloud
• Tier 1 : continue to run in classic environment

What are the categories of Cloud service models ?

Infrastructure-as-a-Service (IaaS)

• IaaS provider provides Cloud infrastructure like, servers, routers, storage and other networking components
• Consumer can deploy and run any software - OS and App
• Consumer does not manage or control the infrastructure, but has control over the OS and deployed applications.

Platform-as-a-Service (PaaS)

• It allows to deploy consumer-created or acquired applications on the Cloud infrastructure.
• The consumer does not manage or control the underlying Cloud infrastructure, such as network, servers, OS, and storage, but controls the deployed applications and possibly the application-hosting environment configurations.
• For PaaS, consumers pay only for the platform software components such as databases, OS instances, and middleware.

Software-as-a-Service (SaaS)

• SaaS allows to use service provider’s applications running on a Cloud infrastructure.
• It is accessible from various client devices through a thin client interface such as a Web browser.
• SaaS reduces the need for infrastructure and manual updates.

What are the essencial concepts of Cloud ?

Abstraction

Cloud computing abstracts the details of system implementation from users and developers.

Applications - run on physical systems that aren't specified

Data - stored in locations that are unknown

Administration of systems - outsourced to others

Virtualization

Cloud computing virtualizes systems by pooling and sharing resources.

Machines and storage - can be provided as needed from a centralized infrastructure

Costs - assessed on a metered basis

Resources - are scalable