www.cloudtp.com Building Blocks of the Private Cloud Private clouds are exactly what they sound like. Your own instance of SaaS, PaaS, or IaaS that exists in your own data center, all tucked away, protected and cozy. You own the hardware, you can hug your server. However, these days what defines a private cloud could also mean systems that are remotely hosted but dedicated to a single enterprise, and in some cases provided out of public cloud data centers as a virtual private cloud. Thus any cloud infrastructure that s dedicated to a single organization is getting the label private cloud. This includes the emerging relabeling of existing enterprise software and hardware solutions, looking to deliver cloud-in-a-box private clouds. If this seems confusing, you re right. The technology vendors and the hype are clearly loading the term private cloud down with everything and anything. However, the concept of private cloud computing has the potential of bringing a huge amount of value to enterprise IT. That is if we understand the right approach, and how to leverage the right technology to create the building blocks of the private cloud. Why go private? Most enterprises are eager to leverage cloud computing, but not so eager to place core business processing and critical business data on public clouds. Indeed, there may even be legal restrictions on where data may exist, as we have seen in the financial and health verticals, where some types data may not exist outside of the enterprise. Or, the risk of having data compromised or lost, outweighs the value that public cloud computing will bring. While the regulations are real, most of those selecting private over public cloud computing do so around the issue of control. Many in enterprise IT don t like to give up control of core business systems considering that is were they may place their own value. Thus, if these
systems are controlled and managed by others outside of the enterprise, then they feel their value will be diminished. In most cases these are false perceptions. Issues around security represent another reason enterprises are more readily turning to private clouds. While public clouds provide rudimentary security subsystems that have thus far had a good track record, most enterprises do not consider them as secure as systems existing on-site, or remotely hosted but completely under the enterprise s control. While public cloud security is getting better, private clouds do offer fewer security risks. Finally, there are performance issues when leveraging public clouds, including the natural latency of leveraging the Internet. This is really a matter of how the applications and systems are designed, more so than limitations of the cloud. Performance concerns are valid in some instances. For example, problem domains with a high amount of data transfer between the data server and the consumer. What s a Private Cloud? NIST defines a private cloud as Cloud infrastructure that is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise. For the most part, that is the definition that many are running with. However, let s go a few steps further to define the core attributes of private clouds, and cloud computing in general. They are: Multi-tenancy and resource pooling Self or auto-provisioning Use-based accounting Security Governance First you ll notice that virtualization is not on the list despite the fact that those leveraging virtualization often call clusters of virtualized servers a private cloud. The reality is that virtualization is often used when building a private cloud. But simple virtualization does not make a private cloud make, whether you choose to leverage it or not. For example, Google s cloud systems do not leverage virtualization while Amazon Web Services (AWS) does. Multi-tenancy & Resource Pooling Multi-tenancy, refers to the managed access to resources, such as storage and compute services in an environment where there is more than one user sharing those resources. This is a critical building block of private cloud computing considering that we could have hundreds or thousands of users sharing the same sets of servers and attached devices, and a thus need to make sure that any particular resource does not get saturated or accessed simultaneously. Moreover, that user and application processes must stay out of each other s way. The mechanisms and approaches to multi-tenancy vary greatly from cloud to cloud, but the objectives are much the same. Related to multi-tenancy, Resource pooling means that the provider s computing resources are 2
pooled to serve multiple consumers using a multi-tenant model. Different physical and virtual resources dynamically assigned and reassigned according to consumer demand. Self or Auto-Provisioning Perhaps the most important concept of private cloud computing is self or auto-provisioning is the ability for an application or a user to allocate resources, such as storage and compute, dynamically during operations. This is typically accomplished by invoking a provisioning API, or in some cases going to a Web page where the resources can be allocated manually. In some cases the resources are automatically provisioned as needed. In addition, these resources can be de-provisioned after use with the same mechanisms. Considering that we re paying for the minutes of use, even within a private cloud, this means we can allocate the resources required to perform an operation, and put them back when done. For instance, allocating a hundred servers to perform a database extraction in 10 minutes, and then returning those server back to the cloud for others to use. Thus, we re being as efficient as possible with both the resources and the dollars spent. This provisioning mechanism also provides the elasticity that many attribute as an advantage of cloud computing, or the ability to expand and contract the use of cloud resources as needed to support the application. Use-Based Accounting Use-based accounting refers to an automated approach to keeping track of those leveraging the private cloud, and charging them back for the use. Considering that most leveraging private clouds are known resources, typically within the same company or governance agency, these are budget dollars. Statements are typically sent that describe the use of resources, duration, and the cost. This is also helpful to understand how applications and users are consuming the private cloud resources, and times of day when system loading could be an issue. Security Security is required to make sure that only those with authorization, including both humans and machines, leverage the private cloud. Typically this is user ID and password role-based security, but lately more sophisticated security models, such as federated identity management have proven to be more effective. We ll cover more about security below. Governance Governance, means that we re not only securing our private cloud but are able to create and manage policies to control access to resources and services. This means that we can define limits on when and how resources, such as storage, compute, and database services, are access by applications and users leveraging the private cloud.? Private Cloud Configurations The latest configurations of private clouds are no longer just for data centers. As introduced above, many private clouds may be outsourced as virtual private clouds within public cloud computing providers. AWS provides just such a service, called Virtual Private Cloud or VPC. 3
Using this services you have the ability to logically group Amazon EC2 instances and assign them to a private IP address, and thus control traffic to and from the server. They also offer an additional layer of security allowing you to create and manage network Access Control Lists (ACLs). Finally, you can connect to the AWS data center using a VPN connection, thus making the VPC an extension of your enterprise network. Moreover, the cloud provider maintains the hardware for you, but you don t have physical access to the servers. In other offerings, public cloud providers may even provide you with access to dedicated physical servers that you never actually see. Of course this is at an additional cost, but many enterprises feel better if their servers are only storing their data. In a virtualized and multitenant cloud, you re mixed in with everyone else using that cloud. Again, you don t have physical access to the hardware, but the maintenance is handled by the cloud provider. Other private clouds may exist in colocation data centers, or CoLos. These are data center rentals where you own a cage full of servers that are tied directly back to the enterprise. Unlike virtual private clouds or virtual private instances you have access to the physical hardware when using this configuration, but that also means you are responsible for maintenance as well. Another approach is something that s been called a cloud-in-a-box, or a server or clusters of servers that have been pre-configured to provide most of the private cloud services listed above. You just purchase the thing has a stand-alone server or appliance, install in the data center, and you have your private cloud. Oracle s Exalogic private cloud solution is an example of a private cloud-in-a-box, that comes at a million dollar starting price. Of course there is the traditional approach to private cloud computing, where software is installed and configured on commodity servers existing within the data center that becomes the private cloud. These servers run private cloud software, that provide most or all of the core private cloud attributes listed above. This is the most popular approach today, with the configurations above gaining more attention in light of the desire for convenience and speed. Building Blocks of Private Cloud The building blocks of private cloud computing include the server virtualization software the many employ as a foundation for creating the private cloud. However, some private cloud solutions don t leverage virtualization, as described above. A common mistake is assuming that several virtualized servers are a private cloud, but without the addition of multi-tenancy, use-based accounting, auto or self-provisioning, and other cloudy features we ve described above, the private cloud functionality won t be there. However, many private cloud solutions are ready made to take advantage of server virtualization, including VMware vcloud Director which leverages VMware hypervisors. Or, if you re going open source, Eucalyptus can use a variety of virtualization technologies including VMware, Xen and KVM hypervisors to implement the cloud abstractions it supports. Private cloud software is mostly purchased as pre-built packages, although it s possible to rollyour-own using various software components that provide the services defined above. Just as with the public cloud space, we can place private clouds into three core categories, including IaaS, PaaS, and SaaS. 4
Private IaaS IaaS private clouds are perhaps the most popular type of private cloud, considering that they provided self provisioned access to core infrastructure services including storage and compute. The most popular packaged IaaS systems include VMware s vcloud Director and Eucalyptus Systems, Inc. s Eucalyptus. However, the popularity of cloud computing is driving newer private cloud software solutions to the market including cloud.com and Nimbula. Moreover, there are private clouds that provide just storage or just database services, and not access to a complete platform of resources. Private PaaS However, there are also PaaS-based private clouds that are beginning to show up in data centers. Like their public computing counterparts, these platforms provide the benefit of shared application development and deployment platforms. Examples of providers in this space include Microsoft with their private cloud version of Azure. Private SaaS Finally, there are SaaS version of private clouds providing access to common application services using a SaaS model, but deployed from a private cloud. These are typically tactical software instances, such as e-mail and calendaring, but can also be system management and even enterprise applications. Cloud service management means that we re leveraging mechanisms to manage the private cloud instance, including allocating and de-allocating servers, user management, security management, and other maintenance issues that need to be dealt with during the operations of the private cloud. While you would think that these services would typically come from the private cloud computing software provider, in some cases they have to be sourced from a third party, such as abstract management of virtualized servers or storage management. Use-based accounting, as defined above, is the ability to track the usage of the private cloud by humans and machines. Again, in many instances this feature will be provided by the private cloud software, but third party software can be integrated, or you may even leverage a public cloud service to perform this function. Security within a private cloud environment is typically pretty basic. In order to create the proper security solution you need to work from the requirements, typically existing security and compliance policies to the solution. While simple role-based security is typically fine for most applications, there are requirements for more sophisticated security mechanism such as advanced encryption, or federated identity solutions that allow for a more granular security configuration. The usual security players including the RSA for encryption and IBM and Oracle for federated identity tech offer compelling solutions. Governance solutions for private cloud computing are perhaps the most overlooked component of the private cloud solution, but something that most of those implementing private cloud services will require at some point. Again, the concept is to place rules and policies around cloud services, insuring that they are leveraged properly by authorized clients. There are a few governance solutions that now support private clouds, including Layer 7, Oracle, and Vordel. 5
So what does the hardware footprint look like for a private cloud? It s really a matter of the capacity you need to support, and can be anywhere from one appliance, to several dozen racks of servers. They can cost from a few hundred dollars to over a million dollars depending on the need and configuration. Best Practices While this is still very much an emerging area, there are some best practices that are beginning to emerge in how to define, design, and implement a private cloud. Focus on the requirements before beginning your journey to a private cloud solution. Many tasked in deploying private clouds often skip the requirements, and thus take a shot in the dark around the best architecture and technology to deploy the private clouds, and thus often miss the mark. As a rule, make sure to move from the requirements, to the architecture, and then to the solution. While the lure of a private cloud-in-a-box is sometimes too difficult to resist, most solutions require a bit more complex solution to deliver real value. Also recommended is the use of service oriented architecture (SOA) approach around the definition and architecture of private clouds. Many are finding that the use of SOA concepts delivering solutions as sets of services that can be configured into solutions, is a perfect match for those designing, building, and deploying private clouds. Define the business value of the private cloud before the project begins. There should be a direct business benefit that is gained from this technology, and considering that many private cloud deployments will cost many millions of dollars, and thus draw questions from management, you need to be prepared to provide solid answers as to the ROI. Work in small increments. While it may seem a good idea to fill half the data center with your new private cloud you ll need the capacity at some point right? Not now. You should only create a private cloud instances with the capacity requirements for the next year. If you ve designed your private cloud correctly, and have leveraged the appropriate vendors, increasing capacity should be as easy as adding additional servers. In Your Future? Private clouds are really a direct copy of the efficiency of public cloud computing architectures re-purposed for internal use within enterprises. However, the benefits are somewhat different as is the technology, architecture, and the way private clouds are deployed. In many respects private clouds are just another internal system, but it s the patterns of use including access to shared resources that can be allocated on-demand where the value of private clouds really shines through. Challenges that exist include the confusion of the term private cloud, which is overused as way to simple push an existing software or hardware product as something that s now a cloud, and thus relevant. This cloud washing has been going on for sometime with everything 6
from disk drives, printers, and scanners being positioned within the emerging space of private cloud as clouds. The only way to counter this confusion is to stick to our guns in terms of what a private clouds is, including its attributes and building blocks as discussed in this article. Without a clear understanding of the concept of a private cloud, and the best practices and approaches to building a private cloud, it won t provide the value we expect. Learn more info@cloudtp.com www.cloudtp.com (617) 674-0874 2015 Cloud Technology Partners, Inc. / 263 Summer Street / 4th Floor / Boston MA, 02210 617.674.0874 / info@cloudtp.com / www.cloudtp.com 7