Welcome!

Microservices Expo Authors: Liz McMillan, Pat Romanski, Stackify Blog, Jason Bloomberg, Elizabeth White

Related Topics: Containers Expo Blog, Microservices Expo, Microsoft Cloud, Linux Containers, Cloud Security, SDN Journal

Containers Expo Blog: Article

Data Efficiency at Scale

Overcoming limitations in data efficiency features

The initial wave of data efficiency features for primary storage focus on silos of information organized in terms of individual file systems. Deduplication and compression features provided by some vendors are limited by the scalability of those underlying file systems, essentially the file systems have become silos of optimized data. For example, NetApp deduplication can't scale beyond a 100 TB limit, because that's the limit in size of its WAFL file system. But ask anyone who's ever used NetApp deduplication if they've done it on a 100 TB file system, and you're likely to hear "are you crazy?" It's one thing to claim that data efficiency features can scale, quite a different one to actually use them with performance at scale.

Challenges around scalability generally center on two areas: scalability of random IO and memory overhead. Older solutions, like the one from NetApp, face the first challenge while newer flash-based storage systems are struggling with the second. I'll review both here:

The IO Challenge
Primary data-oriented storage devices handle both streaming and random throughput and therefore are sensitive to latency effects. Data efficiency requirements for primary storage must have fast hashing techniques to reduce the impact of latency. Fast hashes are non-cryptographic in nature and so require data comparison when used to do deduplication. It works like this:

  1. When a new chunk of data is read in it is first given a name using the hash algorithm.
  2. The system then checks a deduplication index to see if a chunk with that name has been seen before (note that this can consume disk IO and tremendous amounts of memory if done wrong).
  3. If the name has been seen we need to take extra steps. Because fast hashes are non-cryptographic, it is possible to have a name match while the data content differs. This is known in computer science as a hash-collision. To account for this, the existing copy of the chunk must be read in and compared bit-by-bit to the new. If they match, only a reference to the chunk is created. If not, then the new chunk must be written.

Essentially, this form of deduplication means trading a write of a duplicate chunk for a read. Depending on the design of the underlying block virtualization layer, duplicate chunks may be widely dispersed throughout the system. In that case, the bigger the system gets, the more expensive reads get - so processing of duplicate data becomes slower and slower as the storage system fills - this is why you won't find many 100 TB NetApp file systems with deduplication turned on. Certainly not for primary storage applications, the system would be flooded with random read requests and NetApp's deduplication process can end up taking months, years or even never complete.

A number of techniques have been used to reduce the impact of IO in other products. For example, the Hitachi NAS (HNAS) and Hitachi Unified Storage (HUS) solutions from HDS make use of hardware-acceleration to generate cryptographically secure hashes that do not require a data compare at all - this allows for linear scaling of deduplication performance on volumes up to 256 TB in size. Data is also written out before it is deduplicated to avoid introducing any latency through the hash computation process itself.

Permabit's own Albireo Virtual Data Optimizer (VDO) product, a plug-in module for Linux-based storage solutions, takes a different approach but with a similar result. VDO works inline to provide immediate data reduction. When data is written out, the VDO process intelligently lays it out in a sequential pattern, so that subsequent read compares of duplicates are more likely to be sequential as well. Both solutions do a fine job at solving the problem in real world scenarios, they just take different approaches.

The Memory Challenge
Many of today's flash array vendors are providing deduplication using similar fast hashing techniques to what I outlined above. With flash, the cost of doing random reads for read compares is a non-issue (random seeks on flash are much less expensive than for hard drive environments) so the use of the fast hash alone is enough to minimize latency. These systems (such as EMC's recently launched XtremIO product) are focused on delivering performance and the big challenge to performance at scale is available memory (DRAM). As above, after chunks are read in, they are named using a fast hashing algorithm. After that, the flash system must determine whether or not a chunk has been seen before. To get at this information as quickly as possible, flash-based storage systems have tended to use huge amounts of DRAM to cache chunk names in memory. It's not uncommon to see flash storage systems that allocate 16 GB of working cache per TB of storage. To support a 256 TB storage volume, such a system would require a TBs of DRAM. The increased hard costs in terms of more expensive (denser) DIMMS, as well as the increased cost of the server board required to support this many DIMMs combine to make this an extremely costly and unpopular proposition. Combine this with the fact that DRAM prices are not falling at the same rate as flash prices, and you can see why no vendor today makes a 256TB flash storage array with global deduplication capabilities.

The solution to the memory challenge is coming, in the form of a next generation of flash storage products that utilize Albireo indexing and Albireo VDO. Unlike the flash arrays described above, flash-optimized arrays with VDO takes advantage of advanced caching techniques to operate with 128 MB of working cache per TB of storage and deliver excellent performance. With VDO, a 256 TB system can be delivered with as little as 32 GB of RAM while delivering 1M IOPS performance. The net result is a cost effective and easily deployed data efficiency solution for flash arrays.

Conclusion

Deduplication Scalability by Vendor

As you can see in the table above, forward thinking vendors like HDS have done a good job at overcoming limitations in their data efficiency features and have products on the market today that can scale to meet the requirements of the large enterprise. Many other vendors are lagging behind, because of their inability to address IO and/or memory requirements, a serious downfall since data efficiency is at the core of distinguishing storage solutions, a critical end user requirement, and a ‘must have' component for 2014. Permabit's VDO product overcomes both of these limitations through the use of advanced memory-efficient caching techniques.

More Stories By Louis Imershein

As Senior Director of Product Strategy at Permabit Technology Corporation, Louis Imershein is responsible for product evolution and strategic planning for the Albireo family of products. He has 22 years of technical leadership experience in product management, software development and support. Prior to joining Permabit, Imershein was a Senior Product Marketing Manager for the Sun Microsystems Data Management Group. He has a Bachelor's degree in Biological Science from the University of California, Santa Cruz.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@MicroservicesExpo Stories
Enterprise architects are increasingly adopting multi-cloud strategies as they seek to utilize existing data center assets, leverage the advantages of cloud computing and avoid cloud vendor lock-in. This requires a globally aware traffic management strategy that can monitor infrastructure health across data centers and end-user experience globally, while responding to control changes and system specification at the speed of today’s DevOps teams. In his session at 20th Cloud Expo, Josh Gray, Chie...
All organizations that did not originate this moment have a pre-existing culture as well as legacy technology and processes that can be more or less amenable to DevOps implementation. That organizational culture is influenced by the personalities and management styles of Executive Management, the wider culture in which the organization is situated, and the personalities of key team members at all levels of the organization. This culture and entrenched interests usually throw a wrench in the work...
In his session at 20th Cloud Expo, Mike Johnston, an infrastructure engineer at Supergiant.io, discussed how to use Kubernetes to set up a SaaS infrastructure for your business. Mike Johnston is an infrastructure engineer at Supergiant.io with over 12 years of experience designing, deploying, and maintaining server and workstation infrastructure at all scales. He has experience with brick and mortar data centers as well as cloud providers like Digital Ocean, Amazon Web Services, and Rackspace. H...
Docker is sweeping across startups and enterprises alike, changing the way we build and ship applications. It's the most prominent and widely known software container platform, and it's particularly useful for eliminating common challenges when collaborating on code (like the "it works on my machine" phenomenon that most devs know all too well). With Docker, you can run and manage apps side-by-side - in isolated containers - resulting in better compute density. It's something that many developer...
We define Hybrid IT as a management approach in which organizations create a workload-centric and value-driven integrated technology stack that may include legacy infrastructure, web-scale architectures, private cloud implementations along with public cloud platforms ranging from Infrastructure-as-a-Service to Software-as-a-Service.
As many know, the first generation of Cloud Management Platform (CMP) solutions were designed for managing virtual infrastructure (IaaS) and traditional applications. But that’s no longer enough to satisfy evolving and complex business requirements. In his session at 21st Cloud Expo, Scott Davis, Embotics CTO, will explore how next-generation CMPs ensure organizations can manage cloud-native and microservice-based application architectures, while also facilitating agile DevOps methodology. He wi...
When you focus on a journey from up-close, you look at your own technical and cultural history and how you changed it for the benefit of the customer. This was our starting point: too many integration issues, 13 SWP days and very long cycles. It was evident that in this fast-paced industry we could no longer afford this reality. We needed something that would take us beyond reducing the development lifecycles, CI and Agile methodologies. We made a fundamental difference, even changed our culture...
These days, change is the only constant. In order to adapt and thrive in an ever-advancing and sometimes chaotic workforce, companies must leverage intelligent tools to streamline operations. While we're only at the dawn of machine intelligence, using a workflow manager will benefit your company in both the short and long term. Think: reduced errors, improved efficiency and more empowered employees-and that's just the start. Here are five other reasons workflow automation is leading a revolution...
As today's digital disruptions bounce and smash their way through conventional technologies and conventional wisdom alike, predicting their path is a multifaceted challenge. So many areas of technology advance on Moore's Law-like exponential curves that divining the future is fraught with danger. Such is the problem with artificial intelligence (AI), and its related concepts, including cognitive computing, machine learning, and deep learning.
We have Continuous Integration and we have Continuous Deployment, but what’s continuous across all of what we do is people. Even when tasks are automated, someone wrote the automation. So, Jayne Groll evangelizes about Continuous Everyone. Jayne is the CEO of the DevOps Institute and the author of Agile Service Management Guide. She talked about Continuous Everyone at the 2016 All Day DevOps conference. She describes it as "about people, culture, and collaboration mapped into your value streams....
In our first installment of this blog series, we went over the different types of applications migrated to the cloud and the benefits IT organizations hope to achieve by moving applications to the cloud. Unfortunately, IT can’t just press a button or even whip up a few lines of code to move applications to the cloud. Like any strategic move by IT, a cloud migration requires advanced planning.
Did you know that you can develop for mainframes in Java? Or that the testing and deployment can be automated across mobile to mainframe? In his session and demo at @DevOpsSummit at 21st Cloud Expo, Dana Boudreau, a Senior Director at CA Technologies, will discuss how increasingly teams are developing with agile methodologies, using modern development environments, and automating testing and deployments, mobile to mainframe.
As DevOps methodologies expand their reach across the enterprise, organizations face the daunting challenge of adapting related cloud strategies to ensure optimal alignment, from managing complexity to ensuring proper governance. How can culture, automation, legacy apps and even budget be reexamined to enable this ongoing shift within the modern software factory?
“Why didn’t testing catch this” must become “How did this make it to testing?” Traditional quality teams are the crutch and excuse keeping organizations from making the necessary investment in people, process, and technology to accelerate test automation. Just like societies that did not build waterways because the labor to keep carrying the water was so cheap, we have created disincentives to automate. In her session at @DevOpsSummit at 20th Cloud Expo, Anne Hungate, President of Daring System...
Most companies are adopting or evaluating container technology - Docker in particular - to speed up application deployment, drive down cost, ease management and make application delivery more flexible overall. As with most new architectures, this dream takes a lot of work to become a reality. Even when you do get your application componentized enough and packaged properly, there are still challenges for DevOps teams to making the shift to continuous delivery and achieving that reduction in cost ...
Docker is on a roll. In the last few years, this container management service has become immensely popular in development, especially given the great fit with agile-based projects and continuous delivery. In this article, I want to take a brief look at how you can use Docker to accelerate and streamline the software development lifecycle (SDLC) process.
@DevOpsSummit at Cloud Expo taking place Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center, Santa Clara, CA, is co-located with the 21st International 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 ...
Cloud adoption is often driven by a desire to increase efficiency, boost agility and save money. All too often, however, the reality involves unpredictable cost spikes and lack of oversight due to resource limitations. In his session at 20th Cloud Expo, Joe Kinsella, CTO and Founder of CloudHealth Technologies, tackled the question: “How do you build a fully optimized cloud?” He will examine: Why TCO is critical to achieving cloud success – and why attendees should be thinking holistically ab...
DevOps is good for organizations. According to the soon to be released State of DevOps Report high-performing IT organizations are 2X more likely to exceed profitability, market share, and productivity goals. But how do they do it? How do they use DevOps to drive value and differentiate their companies? We recently sat down with Nicole Forsgren, CEO and Chief Scientist at DORA (DevOps Research and Assessment) and lead investigator for the State of DevOps Report, to discuss the role of measure...
While some vendors scramble to create and sell you a fancy solution for monitoring your spanking new Amazon Lambdas, hear how you can do it on the cheap using just built-in Java APIs yourself. By exploiting a little-known fact that Lambdas aren’t exactly single-threaded, you can effectively identify hot spots in your serverless code. In his session at @DevOpsSummit at 21st Cloud Expo, Dave Martin, Product owner at CA Technologies, will give a live demonstration and code walkthrough, showing how ...