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a great deal between vendors. Even though this book focuses on AWS, you need to consider other offerings, including Windows Azure, Google Compute Engine, Rackspace Open Cloud, and IBM SmartCloud Enterprise. In some cases, you might actually find it useful to obtain services from multiple hosts to obtain the best service for a particular need.

Comparing IaaS to SaaS

      SaaS is all about cloud-based applications. Products like online email and office suites are examples of cloud-based applications. A client typically accesses the application using a local application, such as a browser. The browser runs on local hardware, but the application runs on the host hardware. What a client sees is the application running in the browser as if it is working locally. In most cases, the application runs within a browser without any alteration to the local system. However, some applications do require the addition of plug-ins.

      The difference between IaaS and SaaS is the level of service. When working with IaaS, a client typically requires detailed support that spans entire solutions. A SaaS solution may include only the application. However, it can also include the following:

      ❯❯ Application runtimes

      ❯❯ Data access

      ❯❯ Middleware

      ❯❯ Operating system support

      ❯❯ Virtualization

      ❯❯ Server access

      ❯❯ Data storage

      ❯❯ Networking

      

SaaS typically keeps the host completely in control and doesn’t offer any sort of monitoring. Even though the host keeps the application updated and ensures data security, the client company administrators typically can’t access SaaS solutions in any meaningful way. (SaaS offers application usage, but not necessarily application configuration, and is therefore not as flexible as other alternatives.) In addition, the client company typically accepts the application as is, without any modifications or customizations. Using client-developed applications is out of the question in this scenario.

Comparing IaaS to PaaS

      PaaS is more of a development solution than a production environment solution. A development team typically uses PaaS to create custom solutions or modify existing solutions. The development staff has full control over the application and can perform all development-related tasks, such as debugging and testing. As with the SaaS solution, the host normally maintains control over

      ❯❯ Middleware

      ❯❯ Operating system support

      ❯❯ Virtualization

      ❯❯ Server access

      ❯❯ Data storage

      ❯❯ Networking

      In this case, however, the development staff can access the middleware to enhance application development without reinventing the wheel. Writing application code to make the application cloud-ready isn’t necessary because the middleware already contains these features. The development team gains access to cloud-based application features that include the following:

      ❯❯ Scalability

      ❯❯ High availability

      ❯❯ Multitenancy

      ❯❯ SaaS enablement

      

Administrators can also perform monitoring and management tasks within limits when working with a PaaS (depending on the contract the client has with the host). However, realize that PaaS is oriented toward development needs, so the developer takes precedence when it comes to performing some tasks that an administrator might normally perform. In addition, PaaS relates to development, not production setups, so the host may take care of all administration tasks locally.

      Determining Why You Should Use AWS

      Even though AWS has a lot to offer, you still need to consider how it answers your specific needs. This consideration goes beyond simply determining whether you really want to move to cloud-based services, but also takes into account other offerings that might serve your needs just as well (if not better). Even though this book is about AWS, you should compare AWS with other cloud services. You may choose to use AWS as part of your solution rather than as the only solution. Of course, this means knowing the areas in which AWS excels. The following sections address both of these possibilities: using cloud services other than AWS, or in addition to it.

Comparing AWS to other cloud services

      You have many ways to compare cloud services. One of the ways in which companies commonly look at services is by the market share they have. A large market share tends to ensure that the cloud service will be around for a long time and that many people find its services both useful and functional. A recent InfoWorld article (http://www.infoworld.com/article/3065842/cloud-computing/beyond-aws-the-clouds-next-stage.html) points out that AWS currently corners 70 to 80 percent of the cloud market. In addition, AWS revenues keep increasing, which lets Amazon continue adding new features while maintaining existing features at peak efficiency.

      

The cloud services marketplace continues to change at a frantic pace, so you need to keep up-to-date on the various offerings that each provider supplies. In addition, you need to track pricing and other factors that affect your application development process. Your application development needs also change over time, which means that the services you use today may not meet your needs tomorrow. In short, don’t assume that the choices you make are fixed.

      

Large market share and capital to invest don’t necessarily add up to a cloud service that fulfills your needs. You also need to know that the host can provide the products you need in a form that you can use. The AWS product list appears at http://aws.amazon.com/products/. It includes all the major IaaS, SaaS, and PaaS categories. However, you should compare these products to the major AWS competitors:

      ❯❯ Cisco Metapod (http://www.cisco.com/c/en/us/products/cloud-systems-management/metapod/index.html)

      ❯❯ Google Cloud Platform (https://cloud.google.com/products/)

      ❯❯ Joyent (https://www.joyent.com/)

      ❯❯ Microsoft Azure (https://azure.microsoft.com/)

      Of the competitors listed here, Google Cloud Platform comes closest to offering the same feature set found in AWS. However, in looking at the Google offerings, you should note the prominence of machine learning services that aren’t found in AWS. On the other hand, AWS has more to offer in the way of the Internet of Things (IoT), applications, and mobile services.

      Each of the vendors offering these services is different. For example, Joyent offers a simple setup that may appeal more strongly to an SMB that has only a few needs to address and no desire to become involved in a complex service. Microsoft, on the other hand, has strong SQL database-management support as well as the connection with the Windows platform that businesses may want to maintain. The point is that you must look at each of the vendors to determine who can best meet your needs (although, as previously stated, most people are voting with their dollars on AWS).

Defining target areas where AWS works best

      In looking at the services that AWS provides, you can see that the emphasis is on enterprise productivity. For example, Google Cloud Platform offers four enhanced machine learning services that you could use for analysis purposes, but AWS offers only one. However, Google Cloud Platform can’t match AWS when it comes to mobile service, which is an area that users

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