Click here to close now.

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
17th Cloud Expo, taking place Nov 3-5, 2015, 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 enterprises ar...
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, 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 ...
DevOps Summit, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development...
IT data is typically silo'd by the various tools in place. Unifying all the log, metric and event data in one analytics platform stops finger pointing and provides the end-to-end correlation. Logs, metrics and custom event data can be joined to tell the holistic story of your software and operations. For example, users can correlate code deploys to system performance to application error codes. In his session at DevOps Summit, Michael Demmer, VP of Engineering at Jut, will discuss how this can...
"Plutora provides release and testing environment capabilities to the enterprise," explained Dalibor Siroky, Director and Co-founder of Plutora, in this SYS-CON.tv interview at @DevOpsSummit, held June 9-11, 2015, at the Javits Center in New York City.
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding bu...
"AgilData is the next generation of dbShards. It just adds a whole bunch more functionality to improve the developer experience," noted Dan Lynn, CEO of AgilData, in this SYS-CON.tv interview at 16th Cloud Expo, held June 9-11, 2015, at the Javits Center in New York City.
The basic integration architecture, as defined by ESBs, hasn’t changed for more than a decade. Most cloud integration providers still rely on an ESB architecture and their proprietary connectors. As a result, enterprise integration projects suffer from constraints of availability and reliability of these connectors that are not re-usable across other integration vendors. However, the rapid adoption of APIs and almost ubiquitous availability of APIs amongst most SaaS and Cloud applications are ra...
SYS-CON Events announced today that Secure Infrastructure & Services will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Secure Infrastructure & Services (SIAS) is a managed services provider of cloud computing solutions for the IBM Power Systems market. The company helps mid-market firms built on IBM hardware platforms to deploy new levels of reliable and cost-effective computing and hig...
"We help to transform an organization and their operations and make them more efficient, more agile, and more nimble to move into the cloud or to move between cloud providers and create an agnostic tool set," noted Jeremy Steinert, DevOps Services Practice Lead at WSM International, in this SYS-CON.tv interview at @DevOpsSummit, held June 9-11, 2015, at the Javits Center in New York City.
The most often asked question post-DevOps introduction is: “How do I get started?” There’s plenty of information on why DevOps is valid and important, but many managers still struggle with simple basics for how to initiate a DevOps program in their business. They struggle with issues related to current organizational inertia, the lack of experience on Continuous Integration/Delivery, understanding where DevOps will affect revenue and budget, etc. In their session at DevOps Summit, JP Morgenthal...
One of the hottest areas in cloud right now is DRaaS and related offerings. In his session at 16th Cloud Expo, Dale Levesque, Disaster Recovery Product Manager with Windstream's Cloud and Data Center Marketing team, will discuss the benefits of the cloud model, which far outweigh the traditional approach, and how enterprises need to ensure that their needs are properly being met.
The time is ripe for high speed resilient software defined storage solutions with unlimited scalability. ISS has been working with the leading open source projects and developed a commercial high performance solution that is able to grow forever without performance limitations. In his session at Cloud Expo, Alex Gorbachev, President of Intelligent Systems Services Inc., shared foundation principles of Ceph architecture, as well as the design to deliver this storage to traditional SAN storage co...
Overgrown applications have given way to modular applications, driven by the need to break larger problems into smaller problems. Similarly large monolithic development processes have been forced to be broken into smaller agile development cycles. Looking at trends in software development, microservices architectures meet the same demands. Additional benefits of microservices architectures are compartmentalization and a limited impact of service failure versus a complete software malfunction. ...
Discussions about cloud computing are evolving into discussions about enterprise IT in general. As enterprises increasingly migrate toward their own unique clouds, new issues such as the use of containers and microservices emerge to keep things interesting. In this Power Panel at 16th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the state of cloud computing today, and what enterprise IT professionals need to know about how the latest topics and trends affect t...