A Memorandum to IT Pros on Cloud Computing

The IT industry is moving fast with cloud computing. And there are fundamental changes on how to approach businesses, which we must grasp to fully appreciate the opportunities presented to us.

Fabric, Not Virtualization

In cloud computing, resources for consumption are via abstractions without the need to reveal the underlying physical complexities. Ultimately all cloud computing artifacts eventually consist of resources categorized into three pools, namely compute, networking, and storage. Compute is the ability to execute code and run instances. Networking is how instances and resources are glued or isolated. And storage is where the resources, configurations, and data are kept. In current state of technologies, one approach is to deliver resources via a form of virtualization. And these three resource pools are abstracted with server virtualization, network virtualization, and storage virtualization, respectively, to collectively form the so-called fabric, as detailed in “Resource Pooling, Virtualization, Fabric, and Cloud.”

Fabric is an abstraction signifying the ability to discover and manage datacenter resources. Sometimes we refer the owner of fabric as a fabric controller which is essentially a datacenter management solution and manages all datacenter physical and virtual resources, With fabric, a server is delivered with a virtual machine (VM), an IP address space can be logically defined through a virtual network layer, and a disk drive appearing with a massive and continuous storage space is in fact an aggregate of the storage provided by just a bunch of disks. Virtualization is an essential building block of cloud computing. We must however go beyond virtualization and envision “fabric” as the architectural layer of abstraction. 

A critical decision in transforming into cloud computing is to as  early as possible establish a holistic approach of fabric management, i.e. deploying a system management solution to provide a common and comprehensive platform for integrating, managing, and operating the three resource pools. This management solution is to strategically form the fabric such that datacenter resources regardless physical or virtualized, deployed on premises or off premises are all discoverable and manageable in a transparent fashion.

Service Architecture, Not VMs 

Many may consider IaaS is about deploying VMs. In cloud computing, an IaaS deployment is nevertheless not just about individual VMs. Modern computing models employ distributed computing with multiple machine tiers while each tier may have multiple VM instances taking incoming requests or processing data. A typical example is a three-tier web application including a frontend, mid-tier, and backend, which maintains multiple frontend instances for load-balancing and multiple backend instances for high-availability of data. And an application is functional only when all three tiers are considered and operated as a whole. Although there are times, perhaps an application architecture is formed with a single machine tier, i.e. one machine instance constitutes an application instance, and operating directly on a VM is equivalent to that on the service. We must however manage the deployment as a service architecture deployment and not as an individual VM deployment.

A service in cloud computing is an application instance, a security boundary, and a management entity. One will deploy a service, start and stop a service, scale a service, upgrade a service. Service from an operations point of view is a set of VMs collectively maintaining an application architecture, run-time environment, and a running instance. No, cloud computing is not just about deploying VMs, since cloud has no concept on individual VMs. it is about the ability to deploy an application architecture followed by configuring target application run-time environment before finally installing and running an application. It is about a service, i.e. an application. And IaaS is about the ability to deploy a service architecture and not individual VMs.

Services, Not Servers

A similar concept to a service architecture vs. VMs is services vs. servers. Here a server is the server OS instance running in a deployed VM. “Service” is operationally a set of servers which forms a service, or an application, architecture. In the context of cloud computing, a service carries a set of attributes, five to be specific as defined in NIST SP 800-145 and summarized in the 5-3-2 Principle of Cloud Computing. Deploying a server (or a VM) and deploying a service denote very different capabilities. Deploying ten VMs is a process of placing ten individual servers, and it suggests little on the scope, relationship, scalability, and management of the ten servers. At the same time, deploying ten instances of a service denotes there is one service definition and with ten instantiations. The significance of the ten service instances is that since all instances are based on a the same service definition, there is an opportunity to optimize business objectives via “service” management. An example is to employ upgrade domains to eliminate downtime during application upgrade.

A service is also how cloud computing is delivered and consumed.  IaaS, PaaS, and SaaS all ended with the term, service, is a clear indication on how significant a service plays. It is “the” way in cloud computing to deliver resource for consumption. If it is not delivered as a servicer, it is not cloud.

From a customer’s point of view, a service (i.e. an application) is what is consumed. Therefore IT pros should pay attention to what is running within a server and not just the server itself. Form a system management viewpoint, what matters is the ability to look into a server instance and drill down to application level, and gain insights of application usage and health. For instance, for a database application what is critical to know and respond to is the health of databases and not just the state of the server which hosts the database application.

So for IT pros, cloud computing is more than just how a server is automatically configures and deployed, it is how the application running in the server instance is defined, constructed, deployed, and managed including fault domain and upgrade domain, availability, geo-redundancy, SLA, pricing, costs, cross-site recovery, etc.

Hybrid, Not On-Premises

With virtualization in place, enterprise IT can accelerate cloud computing adoption by hybrid deployment scenarios. Here a hybrid cloud is a private cloud with a cross-premises deployment. For example an on-premises private cloud with some off-premises resources is a form of hybrid cloud, and vice versa. A hybrid cloud based on an on-premises private cloud offers an opportunity for keeping sensitive information on premises while taking advantages of the flexibility and readiness that a 3rd-party cloud service provider can provide to host non-sensitive data. An on-premises private cloud solution is a stepping stone, the ability to define, deploy, and manage a hybrid cloud is where IT needs to be. 

The idea of a hybrid cloud surfaces an immediate challenge: how to enable a user to self-serve resources in a cross-premises deployment. Self-servicing is an essential characteristic in cloud computing and plays a crucial role in fundamentally minimizing training and support cost while continually promoting resource consumption. For a hybrid IT environment, there are strategically important considerations including consistent user experience with on-premises and off-premises deployments, SSO maturity and federated identity solutions, a manageable delegation model, and inter-op capabilities with 3rd-party vendors. To ensure IT agility, a management platform to manage resources not just physical and virtualized, but also those deployed to a private cloud, a public cloud, or a hybrid cloud is increasingly critical.

Closing Thoughts

Transitioning into cloud computing platform is critical for enterprise IT to compete in the emerging economy which is driven by emotions and current events and intensified by social media. IT should institute a comprehensive management solution while the first opportunity arises to facilitate and converge fabric construction with cloud computing methodology. Keep staying focused on constructing, deploying, and managing:

  • Not virtualization, but fabric
  • Not VMs, but a service architecture
  • Not servers, but service instances
  • Not on-premises, but hybrid deployment scenarios

For enterprise IT, the determining factor of a successful transformation is the ability to continue managing not only what has been established, but what is emerging; not only physical and virtualized, but those deployed to private, public, and hybrid clouds; not only from one vendor’s solution platform, but vSphere, Hyper-V, Citrix and beyond.

One thought on “A Memorandum to IT Pros on Cloud Computing

  1. Pingback: My Presentation at The Univ. of Texas at Arlington | yungchou

Comments are closed.