PaaS | Platform as a service
  1. PaaS stands for platform as a service.
  2. PaaS provides a computing platform with a programming language execution environment.
  3. PaaS provide a development and deployment platform for running applications in the cloud. 
  4. PaaS constitute the middleware on top of which applications are built.
  5. Application management is the core functionality of the middleware.
  6. PaaS provides run time environments for the applications.
  7. PaaS provides
    •  Applications deployment
    • Configuring application components
    • Provisioning and configuring supporting technologies 
  8. For users PaaS interfaces can be in the form of a Web-based interface or in the form of programming APIs and libraries.
  9. PaaS solutions generally include the infrastructure as well.
  10. PurePaaS offered only the user-level middleware.
  11. PaasS classification:
    1. PaaS-I:  Runtime environment with Web-hosted application development platform. Rapid application prototyping. For example which is a combination of middleware and infrastructure product type.
    2. PaaS-II: Runtime environment for scaling Web applications. The runtime could be enhanced by additional components that provide scaling capabilities. For example Google AppEngine which is a combination of middleware and infrastructure product type. Appscale is middlware product type.
    3. PaaS-III: Middleware and programming model for developing distributed applications in the cloud. For example Microsoft Azure which is a combination of middleware and infrastructure product type. Manjrasoft Aneka is a middleware product type.
  12. Some examples:
    • Google App Engine
PaaS reference model
From the book of Sir Rajkumar Buyya
PaaS reference model

Characterstics of PaaS:
  1. Runtime framework: The runtime framework executes end-user code according to the policies set by the user and the provider. 
  2. Abstraction: PaaS offer a way to deploy and manage applications on the cloud rather than a virtual machines on top of which the IT infrastructure is built and configured. 
  3. Automation: PaaS deploy the applications automatically.
  4. Cloud services: Provide services for creation, delivery, monitoringm management, reporting of applications.
More topics from Cloud Computing to read
Cloud Computing: covered following topics in these notes.
  1. Introduction to Cloud Computing
  2. Historical development of Cloud Computing 
  3. Vision of Cloud Computing
  4. Characteristics of cloud computing as per NIST
  5. Cloud computing reference model
  6. Cloud computing environments
  7. Cloud services requirements
  8. Cloud and dynamic infrastructure
  9. Cloud Adoption and rudiments
  10. Cloud application: ECG Analysis in the cloud
  11. Cloud application: Protein structure prediction
  12. Cloud application: Gene Expression Data Analysis
  13. Cloud Computing Architecture
  14. IaaS
  15. PaaS
  16. SaaS
  17. Types of Clouds
  18. Cloud Interoperability & Standards
  19. Scalability and Fault Tolerance
  20. Cloud Ecosystem
  21. Cloud Business Process Management
  22. Cloud Service Management
  23. Cloud Analytics
  24. Testing Under Control
  25. Virtual Desktop Infrastructure
  26. Cloud Resiliency
  27. Cloud Provisioning
  28. Asset management
  29. Concepts of Map reduce
  30. Cloud Governance
  31. High Availability and Disaster Recovery
  32. Virtualization in cloud computing
  33. Server virtualization
  34. Hypervisor management software
  35. Third Party Cloud Services
  36. Case Study: Google App Engine
  37. Case Study: Microsoft Azure
  38. Case Study: Hadoop
  39. Case Study: Amazon
  40. Case Study: Aneka
A list of Video lectures
  1. Buyya, Selvi ,” Mastering Cloud Computing “,TMH Pub
  2. Krutz , Vines, “Cloud Security “ , Wiley Pub
  3. Velte, “Cloud Computing- A Practical Approach” ,TMH Pub
  4. Sosinsky, “ Cloud Computing” , Wiley Pub
Python Programming ↓ 👆
Java Programming ↓ 👆
JAVA covered following topics in these notes.
JAVA Programs
Principles of Programming Languages ↓ 👆
Principles of Programming Languages covered following topics in these notes.

Previous years solved papers:
A list of Video lectures References:
  1. Sebesta,”Concept of programming Language”, Pearson Edu 
  2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
  3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
  4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley

    Computer Organization and Architecture ↓ 👆

    Computer Organization and Architecture covered following topics in these notes.

    1. Structure of desktop computers
    2. Logic gates
    3. Register organization
    4. Bus structure
    5. Addressing modes
    6. Register transfer language
    7. Direct mapping numericals
    8. Register in Assembly Language Programming
    9. Arrays in Assembly Language Programming


    1. William stalling ,“Computer Architecture and Organization” PHI
    2. Morris Mano , “Computer System Organization ”PHI

    Computer Network ↓ 👆
    Computer Network covered following topics in these notes.
    1. Data Link Layer
    2. Framing
    3. Byte count framing method
    4. Flag bytes with byte stuffing framing method
    5. Flag bits with bit stuffing framing method
    6. Physical layer coding violations framing method
    7. Error control in data link layer
    8. Stop and Wait scheme
    9. Sliding Window Protocol
    10. One bit sliding window protocol
    11. A protocol Using Go-Back-N
    12. Selective repeat protocol
    13. Application layer
    1. Andrew S. Tanenbaum, David J. Wetherall, “Computer Networks” Pearson Education.
    2. Douglas E Comer, “Internetworking with TCP/IP Principles, Protocols, And Architecture",Pearson Education
    3. KavehPahlavan, Prashant Krishnamurthy, “Networking Fundamentals”, Wiley Publication.
    4. Ying-Dar Lin, Ren-Hung Hwang, Fred Baker, “Computer Networks: An Open Source Approach”, McGraw Hill.