Windows Azure Compute…
Windows Azure offers an internet-scale hosting environment built on geographically distributed data centers. This hosting environment provides a runtime execution environment for managed code. A Windows Azure compute service is built from one or more roles. A role defines a component that may run in the execution environment; within Windows Azure, a service may run one or more instances of a role. A service may be comprised of one or more types of roles, and may include multiple roles of each type.
Windows Azure supports three types of roles: A Web role-customized for web application programming and supported by IIS 7. These Web roles run IIS7. A Worker role is used for generalized development, and may perform background processing for a web role. A Virtual Machine (VM) role that runs an image—a virtual hard disk (VHD)—of a Windows Server 2008 R2 virtual machine. This VHD is created using an on-premises Windows Server machine, then uploaded to Windows Azure. Once it’s stored in the cloud, the VHD can be loaded on demand into a VM role and executed. Customers can configure and maintain the OS and use Windows Services, scheduled tasks etc. in the VM role.
Web and Worker Role Enhancements:
At PDC 10, we announced the following Web and Worker role enhancements: Development of more complete applications using Windows Azure will soon be possible with the introduction of Elevated Privileges and Full IIS . The new Elevated Privileges functionality for the Web and Worker role will provide developers with greater flexibility and control in developing, deploying and running cloud applications. The Web role will also include Full IIS functionality, which enables multiple IIS sites per Web role and the ability to install IIS modules. Windows Azure will also provide Remote Desktop functionality, which enables customers to connect to a running instance of their application or service in order to monitor activity and troubleshoot common problems.
The VM role functionality is being introduced to make the process of migrating existing Windows Server applications to Windows Azure easier and faster. This is especially true for the migration of Windows Server applications that have long, non-scriptable or fragile installation steps. While the VM role offers additional control and flexibility, the Windows Azure Web and Worker roles offer additional benefits over the VM role. Developers focus primarily on their application, and not the underlying operating system. In particular, Visual Studio is optimized for creating, testing, and deploying Web and worker roles – all in a matter of minutes. Also, because developers work at a higher level of abstraction with Web and worker roles, Windows Azure can automatically update the underlying operating system.
VM Role or Elevated Privileges:
The VM role and elevated privileges functionality removes roadblocks that today prevent developers from having full control over their application environment. For small changes like configuring IIS or installing an MSI we recommend using the elevated privilege admin access feature. This approach is best suited for small changes and enables the developer to retain automated service management at the Guest OS and the application level. When the customizations are large in number or require changes that cannot be automated, we recommend using the VM role instead. When developers use the VM role, they retain most benefits of automated service management (load balancing and failover) with the exception of Guest OS patching.
If you would like to be notified when these Windows Azure features are available, and when we’re accepting registrations for the VM role and Extra Small instance Beta as well as the Windows Azure Connect CTP, please click here . For more information about designing and developing roles, see Building Windows Azure Services.
Compute Instance Sizes:
Developers have the ability to choose the size of VMs to run their application based on the applications resource requirements. Windows Azure compute instances come in five unique sizes to enable complex applications and workloads. We are introducing the Extra Small Windows Azure instance to make the process of development, testing and trial easier for enterprise developers. The Extra Small instance will also make Windows Azure more affordable for developers interested in running smaller applications on the platform.