Welcome!

Related Topics: SDN Journal, Containers Expo Blog

SDN Journal: Blog Feed Post

Data Center Architecture: Together and Apart

The datacenter represents a diverse set of orchestrated resources bound together by the applications they serve

The challenge in architecting, building, and managing data centers is one of balance. There are forces competing to both push together and pull apart datacenter resources. Finding an equilibrium point that is technological sustainable, operationally viable, and business friendly is challenging. The result is frequently a set of compromises that outweigh the advantages.

Logically together

The datacenter represents a diverse set of orchestrated resources bound together by the applications they serve. At its most simplest, these resources are physically co-located. At its extreme, these resources are geographically distributed across many sites. Whatever the physical layout, these resources are under pressure to be treated as a single logical group.

Resource collaboration - The datacenter is a collection of compute and storage resources that must work in concert in support of application workloads. The simple requirement of coordination creates an inward force pulling resources closer together, even if only logically. How can multiple elements work together towards a common goal if they are completely separate?

The answer is that they cannot. And as IT moves increasingly towards distributed applications, the interdependence between resources only grows.

Interestingly, the performance advantages of distributed architectures are only meaningful when communication between servers is uninhibited. If the network that makes communication possible slows down, the efficacy of the distributed architecture decreases. This means that datacenter architects must solve simultaneously for compute and storage demand, and the interconnect capacity required between them.

Resource availability - Building out a datacenter is an exercise in matching resource capacity to demand. But not just in aggregate.

Individual applications, tenants, and geographies all place localized demands on datacenter resources. If the aggregate demand is sufficient but the resources exist in separate resource pools, you end up in a perpetual state of mismatch. There is always too much or too little workload capacity. The former means you have overbuilt. The latter leaves you wanting for more, which oddly enough means you end up having to overbuild.

Combatting these resource islands requires pulling resources closer together. In the most simple case, this is a physical act. But even if resources cannot be physically co-located, there are entire classes of technologies whose primary function is to allow physically separate resources to behave as if they are in close proximity.

Of course this does not come without a cost. The complexity of managing the disparate technologies required to logically pool physically separate resources can be prohibitively difficult. Even the most skilled specialists have to invest time in creating a properly engineered fabric between sites that accounts for queuing, prioritization, load balancing, and so on. The number of protocols and technologies required is high, and the volume of devices over which they must be applied can be huge. The result is a level of complexity that makes the network more expensive to manage and more difficult to change.

Organizational process - Friction is greatest at boundaries. Whenever a task requires involvement across different organizations or teams, the act of human coordination imposes a tax on both effort and time. In larger organizations, the handoff between teams might be automated to reduce communication mistakes (as with a ticketing system), but the shift in context is still expensive.

This creates organizational pressure to pull together things that might otherwise be separate. If distributed resources can be logically centralized and managed within a common organization, it reduces the dependence on outside teams. The removal of boundaries from common workflows lowers organizational friction and makes easier the overall task of managing the infrastructure.

Physically separate

At the same time that forces are pulling things together, there are equally strong oppositional forces exerting outward pressure on datacenter resources.

Business continuity - For many companies, the datacenter represents a mission critical element of their infrastructure. For companies whose existence depends on the presence of the resources within the datacenter (be they data, servers, or applications), it is untenably risky to rely on a single physical site. This exerts an outward force on resources as companies must create multiple physical sites, typically separated by enough distance that a disaster would not meaningfully impact all sites.

Despite the operational desire to keep things together, the risk to the business dictates that resources be physically separate.

Natural expansion - As resources are added to a datacenter, they are typically installed in racks in relative close proximity to each other. When racks are empty, there is no reason to unnecessarily create physical separation between resources working in concert. Over time, adjacent rack space is filled through the natural expansion of compute, storage, and networking capacity.

As equipment expands, available rack space is depleted, and new racks and rows are populated. Eventually, the device sprawl can occupy entire data centers.

Imagine now that a cluster of servers occupies a rack in one corner of the datacenter. If that cluster is to be expanded, where does the next server go? If the nearby racks are already built out, that resource must be installed some physical distance away from the resources with which it must coordinate.

It is near impossible to plan for all future growth at the time of datacenter inception. Leaving enough space in adjacent racks to account for a decade of growth is impractically expensive. A sparsely populated datacenter suffers from poor space utilization, challenging power distribution, and difficult cabling. Thus, the mere act of expansion actually exerts an outward force leading to physically distributed resources.

Real estate - Sometimes, even when architects want to keep resources together, physical limitations create problems. There is no more immovable object than real estate (which serves as a proxy for all of space, power, and HVAC). In some cases, it is impossible to build out either laterally or even up. In other cases, there is no additional power to be had from the grid. Either of these scenarios forces an expansion to another site, which requires the physical separation of resources that might be expected to function in concert.

Additionally, as land rates change and technologies evolve, the best spots for data centers are not always known. It is difficult at best to predict with enough certainty how a physical site will evolve over an arbitrarily long time horizon. For example, not long ago, the thought of building cooling-hungry data centers in the hot desert was foreign. Today, Las Vegas is home to some of the most cutting edge facilities in the world. This means that geographical dispersion is likely a certainty for large companies. The forces pulling resources physically apart are unlikely to be neutralized.

Finding a balance

Given the strong forces working to keep resources logically together and the equally strong forces keeping them physically separate, how does anyone find a balance?

The price for balance is cost and complexity. You pay for reach directly, and control requires complexity. Both translate into higher carrying costs for the infrastructure. The push-pull dynamic in datacenters is not going away anytime soon. In fact, a move towards more distributed applications will only make harder the balancing act that already exists.

Newer technology offerings like SDN and datacenter fabrics offer some hope, but only insofar as they offer alternatives to the existing problems. Whatever the solution, architects will need to evaluate approaches based not just on the features but on the long-term costs of those features.

[Today’s fun fact: “Way” is the most frequently used noun in the English language. No way!]

The post Datacenter architecture: Together and apart appeared first on Plexxi.

More Stories By Michael Bushong

The best marketing efforts leverage deep technology understanding with a highly-approachable means of communicating. Plexxi's Vice President of Marketing Michael Bushong has acquired these skills having spent 12 years at Juniper Networks where he led product management, product strategy and product marketing organizations for Juniper's flagship operating system, Junos. Michael spent the last several years at Juniper leading their SDN efforts across both service provider and enterprise markets. Prior to Juniper, Michael spent time at database supplier Sybase, and ASIC design tool companies Synopsis and Magma Design Automation. Michael's undergraduate work at the University of California Berkeley in advanced fluid mechanics and heat transfer lend new meaning to the marketing phrase "This isn't rocket science."

Latest Stories
Identity is in everything and customers are looking to their providers to ensure the security of their identities, transactions and data. With the increased reliance on cloud-based services, service providers must build security and trust into their offerings, adding value to customers and improving the user experience. Making identity, security and privacy easy for customers provides a unique advantage over the competition.
Qosmos has announced new milestones in the detection of encrypted traffic and in protocol signature coverage. Qosmos latest software can accurately classify traffic encrypted with SSL/TLS (e.g., Google, Facebook, WhatsApp), P2P traffic (e.g., BitTorrent, MuTorrent, Vuze), and Skype, while preserving the privacy of communication content. These new classification techniques mean that traffic optimization, policy enforcement, and user experience are largely unaffected by encryption. In respect wit...
Fact: storage performance problems have only gotten more complicated, as applications not only have become largely virtualized, but also have moved to cloud-based infrastructures. Storage performance in virtualized environments isn’t just about IOPS anymore. Instead, you need to guarantee performance for individual VMs, helping applications maintain performance as the number of VMs continues to go up in real time. In his session at Cloud Expo, Dhiraj Sehgal, Product and Marketing at Tintri, wil...
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
Enterprises have forever faced challenges surrounding the sharing of their intellectual property. Emerging cloud adoption has made it more compelling for enterprises to digitize their content, making them available over a wide variety of devices across the Internet. In his session at 19th Cloud Expo, Santosh Ahuja, Director of Architecture at Impiger Technologies, will introduce various mechanisms provided by cloud service providers today to manage and share digital content in a secure manner....
Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, will deep dive into best practices that will ensure a successful smart city journey.
SYS-CON Events announced today that 910Telecom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and ...
To leverage Continuous Delivery, enterprises must consider impacts that span functional silos, as well as applications that touch older, slower moving components. Managing the many dependencies can cause slowdowns. See how to achieve continuous delivery in the enterprise.
There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
SYS-CON Events announced today Telecom Reseller has been named “Media Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
DevOps at Cloud Expo – being held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Am...
I wanted to gather all of my Internet of Things (IOT) blogs into a single blog (that I could later use with my University of San Francisco (USF) Big Data “MBA” course). However as I started to pull these blogs together, I realized that my IOT discussion lacked a vision; it lacked an end point towards which an organization could drive their IOT envisioning, proof of value, app dev, data engineering and data science efforts. And I think that the IOT end point is really quite simple…
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
StarNet Communications Corp has announced the addition of three Secure Remote Desktop modules to its flagship X-Win32 PC X server. The new modules enable X-Win32 to safely tunnel the remote desktops from Linux and Unix servers to the user’s PC over encrypted SSH. Traditionally, users of PC X servers deploy the XDMCP protocol to display remote desktop environments such as the Gnome and KDE desktops on Linux servers and the CDE environment on Solaris Unix machines. XDMCP is used primarily on comp...
Traditional on-premises data centers have long been the domain of modern data platforms like Apache Hadoop, meaning companies who build their business on public cloud were challenged to run Big Data processing and analytics at scale. But recent advancements in Hadoop performance, security, and most importantly cloud-native integrations, are giving organizations the ability to truly gain value from all their data. In his session at 19th Cloud Expo, David Tishgart, Director of Product Marketing ...