Collegenote
- Defining the Cloud
- Cloud Computing
- Emergence of Cloud Computing
- Cloud Based Service Models
- Grid Computing or Cloud Computing
- Components of Cloud Computing
- Cloud Computing Deployment Models
- Benefits of using cloud models
- Legal Issues in Using Cloud Models
- Ethical issues in cloud computing
- Characteristics of Cloud Computing
- Evolution of cloud computing
- Challenges for cloud computing
- Grid Computing
- Distributed Computing in Grid and Cloud
- Cloud Communication
- Communication-as-a-Service (CaaS)
- Advantages of CaaS
- Infrastructure-as-a-Service (IaaS)
- Popular IaaS solutions
- Modern On-Demand Computing
- Amazon’s Elastic Cloud
- Amazon EC2 Service Characteristics
- Elastic IP Addressing
- Monitoring-as-a-Service (MaaS)
- The Traditional On-Premises Model
- Platform-as-a-Service (PaaS)
- Key Characteristics of PaaS
- Software-as-a-Service
- SaaS Implementation Issues
- The key characteristics of SaaS
- Benefits of SaaS Model
- Jericho Cube Model
- XaaS
- Evolution from Managed service providers (MSP) to Cloud Computing
- Single Purpose architectures to multi-purpose architectures
- Service Oriented Architectures (SOA)
- Combining Cloud and SOA
- Characterizing SOA
- Open Source Software in Data Centers
- Data center virtualization
- Cloud data center
SaaS Implementation Issues #
Many types of software components and applications frameworks may be employed in the development of SaaS applications. Using new technology found in these modern components and application frameworks can drastically reduce the time to market and cost of converting a traditional on-premises product into a SaaS solution. According to Microsoft, SaaS architectures can be classified into one of four maturity levels whose key attributes are ease of configuration, multitenant efficiency, and scalability. Each level is distinguished from the previous one by the addition of one of these three attributes. The levels described by Microsoft are as follows
SaaS Architectural Maturity Level 1—Ad-Hoc/Custom: The first level of maturity is actually no maturity at all. Each customer has a unique, customized version of the hosted application. The application runs its own instance on the host’s servers. Migrating a traditional non-networked or client-server application to this level of SaaS maturity typically requires the least development effort and reduces operating costs by consolidating server hardware and administration
SaaS Architectural Maturity Level 2—Configurability: The second level of SaaS maturity provides greater program flexibility through configuration metadata. At this level, many customers can use separate instances of the same application. This allows a vendor to meet the varying needs of each customer by using detailed configuration options. It also allows the vendor to ease the maintenance burden by being able to update a common code base.
SaaS Architectural Maturity Level 3—Multitenant Efficiency: The third maturity level adds multitenancy to the second level. This results in a single program instance that has the capability to serve all of the vendor’s customers. This approach enables more efficient use of server resources without any apparent difference to the end user, but ultimately this level is limited in its ability to scale massively.
SaaS Architectural Maturity Level 4—Scalable: At the fourth SaaS maturity level, scalability is added by using a multitiered architecture. This architecture is capable of supporting a load-balanced farm of identical application instances running on a variable number of servers, sometimes in the hundreds or even thousands. System capacity can be dynamically increased or decreased to match load demand by adding or removing servers, with no need for further alteration of application software architecture.