Provisioning Infrastructure Supporting Cloud Operations

3.1 Development goals

There are already several cloud services in existence, including that of the NTT Group. On-demand self-service [1] is a widely accepted property of clouds, performing resource provisioning according to instructions received from users, so the management system, and in particular the provisioning function, is a basic feature of a cloud service.

These existing cloud services provide various types of services at various layers, according to business needs. This trend is expected to accelerate in the future [2].

The provisioning functions in existing services can be considered to optimize specific computing re-sources according to their properties. On the other hand, the speed with which the provisioning function can be developed when providing a new computing resource must not become an obstacle to the business.

Thus, with the CBoC provisioning infrastructure, we have abstracted the control model so that various computing resources can be supported very quickly, helping to accelerate business development. The operation of various computing resources can also be optimized daily (automatically in the future) through the operational cycle discussed above.

3.2 Central concepts

Below, we describe the central concepts implemented by the features of the CBoC provisioning infrastructure, which allow various computing resources to be added quickly and applications to be integrated easily.

3.2.1 Resource abstraction and connection between resources

One question that arises is whether particular computing resources will behave differently, though we talk about all resource types together. However, from a provisioning perspective, the important things are the fixed operations: create, allocate, initialize, activate, deactivate, finish, free, and delete. If we consider a specific example, these fixed operations apply to both virtual machines (kernel-based virtual machine (KVM) and VMware) and virtual local area networks (VLANs), allowing them to be handled in a unified way by the provisioning infrastructure. The CBoC provisioning infrastructure uses this concept to abstract all of the objects that it handles as resources (of course, in addition to the fixed operations, it also provides ways to handle attributes and operations particular to a given resource).

Another question that arises is whether the process of connecting a virtual machine to a LAN can be abstracted. However, connections between resources are also abstracted, including definitions for a connection's source and destination as well as connection operations, and these definitions regulate what connections and what connection operations are possible. In this way, virtual machines and VLANs can connect, and higher-layer connections, such as those between an application and a database, can also be automated.

This abstraction enables new resources to be added easily to the CBoC provisioning infrastructure. By creating a driver that operates the execution system and by writing template data (resource definitions, connection definitions, and connection operation definitions), one can integrate a new resource into the system.

The development required when new resources are added is also a concern. It is true that creating a resource driver involves development. However, a resource re-definition procedure can be used, even for small-scale cases. Resource re-definition is a function for creating new template data from the existing resource status and its template data, without writing programs or creating template data from scratch. This function makes it easy to perform operations such as creating a new template of a virtual machine with installed applications from a virtual machine with only the installed operating system.

3.2.2 Virtual environment operation, asynchronous scenario processing

In many cases with cloud services like Amazon's, the focus is on handling individual virtual machines. On the other hand, in ordinary system development, it is instead more common to bundle multiple processors and treat them as a single system or development environment. The CBoC provisioning infrastructure uses a virtual environment approach, modeling the system being provided by the user. When a system is being developed or a service is being provided, multiple resources can be conveniently bundled in a virtual environment, enabling batch operations (start, end, backup, etc.).

Resource operations are basically considered to be asynchronous. Operations on real resources such as launching a virtual machine usually take time, so processing is done asynchronously with respect to user requests.

Asynchronous processing is relatively easy to implement for individual virtual machine operations, but for batch operations in a virtual environment with multiple virtual machines, it is more complex. As an example, what would need to be done in a state where one virtual machine was stopped, another virtual machine was assigned but was not processing yet, and you want to transition them to a completed state all at once? With the CBoC provisioning infrastructure, operating procedures are generated automatically, taking into account the current state of resources bundled in the virtual environment and the state of connections between them.

3.2.3 CBoC provisioning infrastructure configuration

Keeping in mind the need to accelerate business development, the various components of the CBoC provisioning infrastructure were designed to be pluggable, with well-defined interfaces, so that only the required parts for a given application need be developed or modified. These components are shown in Fig. 3. The types of interfaces and their applications are also listed in the Table 1.

Fig. 3. CBoC provisioning infrastructure components.

Table 1. CBoC provisioning-infrastructure external interfaces.

4.1 Application to the R&D cloud

Starting in October 2011, we plan to apply the CBoC provisioning infrastructure to the R&D cloud as a development environment lending service components. The configuration for the R&D cloud includes authentication linked with the Open Light Directory Access Protocol (OpenLDAP), project management, role-based authorization, and group quota checking. It uses a web-based console screen (Fig. 4) and allows users to build and operate their own development and testing environments using virtual machines and VLANs.

Fig. 4. Web console for the R&D cloud.

Prior to the R&D cloud, NTT was operating a development environment lending service manually. Experience with it showed that the actual work time required was approximately 5.5 hours, from applying to use the system to actually beginning to use it, and that other work was also required, such as 8.5 hours to create a virtual machine template. The CBoC provisioning infrastructure should reduce this work significantly. Since these figures are based on actual working time, the waiting time for users will be reduced even more, which will increase user satisfaction.

4.2 Evaluating ease with which resource drivers for products on the market can be created

As part of the process of evaluating virtual network products in NTT, we have created a resource driver that handles the product controller and have linked it with a KVM driver for evaluation. The evaluator was not particularly familiar with virtual network products, but was still able to create the resource driver in about one person-month, including testing and integrating the virtual network product into the self-provisioning environment.

Considering that this resource driver was produced internally by laboratory staff, without the quality control of a commercial product, that there is currently no development guide, and that there are many other variable factors, this evaluation result shows that it is easy to create resource drivers. It also shows that it will be easy to quickly integrate various new computing resources provided in the future into the system.