Welcome!

Java IoT Authors: APM Blog, Stackify Blog, XebiaLabs Blog, Liz McMillan, William Schmarzo

Related Topics: Containers Expo Blog, Java IoT, Linux Containers, Open Source Cloud, @CloudExpo, SDN Journal

Containers Expo Blog: Article

Preserving Storage I/O for Critical Applications

Is hypervisor side I/O throttling enough?

While server virtualization has unprecedented advantages, it has thrown some challenges as well. Prior to server virtualization, each application used to run on a dedicated server with dedicated storage connected through dedicated switch ports. Needless to say, this approach had multiple limitations in terms of lack of flexibility, underutilization, etc. But, it provided guaranteed hardware resources such as CPU, network, memory, and storage bandwidth for each application.

With server virtualization, the underlying hardware resources are shared. Hypervisors do a good job in terms of providing guaranteed CPU power, network bandwidth, and memory for each application that shares these resources. However, when it comes to storage, things get complicated. Hypervisors don't have access to resources running inside the storage arrays and can only control access to storage through I/O throttling. This is not enough to preserve the storage I/O for critical applications. As a result, critical applications stay sidelined and the old school method of dedicated hardware approach prevails.

Many factors contribute to the complexity of storage even though the general perception is that storage is just a piece of hardware. In reality, there is a complex piece of software running in the system utilizing various hardware components such as CPU, cache, disk, and network, inside the storage array. Incoming I/Os add various amounts of pressure on these resources based on the traffic pattern. For example, 100 IOPS from Oracle is quite different from 100 IOPS from MS Exchange as far as the storage array is concerned. They are different in terms of read/write ratio, block size, random sequencial, disk placements, deduplication, compression, and so on.

Irrespective of I/O throttling at the hypervisor level, customers often complain: "My applications were running fine till yesterday; but why this sluggish performance now? There can be many factors contributing to this situation. Let us examine some of the common ones:

  • A new application replaces the old application, consuming storage from the array. From the hypervisor point of view, both the new and old applications are sending the same amount of IOPS towards the storage array. But, the new application completely wipes out cache for all the other applications in the storage array since it accesses the same data again and again which keeps this cache hot while depleting other caches.
  • Some applications change the traffic patterns drastically. The classic example is that of Accounting applications that generate month-end or quarter-end reports, depleting the storage resource for other ones. The hypervisor doesn't differentiate between regular I/O and report generation I/O.
  • An application creates and deletes large files. As far as the hypervisor is concerned, that's just a few I/Os, but that strains the storage array resources heavily.
  • One volume is configured for more frequent snapshot creation and deletion; something that is completely inaccessible to the hypervisor.
  • An application that accesses historical data starts to dig data from passive tiers, transparent to the hypervisor, but adds more load on the storage arrays.
  • A filesystem in the storage array is aging and results in more fragmentation. This costs more storage resources to pull out the same amount of data as before. But the hypervisor has no clue about these aspects.
  • Storage arrays' in-house activities, such as garbage collection reduce the overall capability of the array. Here, a simple hypervisor I/O throttling doesn't guarantee the critical applications the required IOPS.
  • Storage arrays' component failures result in reduced capabilities. The hypervisor can't do much to maintain the I/O level for critical applications.

No. Hypervisor side I/O throttling is not just enough. Storage needs to be intelligent to deliver differential, consistent, guaranteed IOPS to each application or virtual machines sharing the storage array. To get end-to-end SLA, all the three layers of the data center such as hypervisor/server, network, and storage need to satisfy individual SLAs. One component cannot act on behalf of the other.

All these years of experience in networking and storage have taught me: storage is the most complex part when it comes to delivering SLA.

More Stories By Felix Xavier

Felix Xavier is Founder and CTO of CloudByte. He has more than 15 years of development and technology management experience. He has built many high-energy technology teams, re-architected products and developed features from scratch. Most recently, Felix helped NetApp gain leadership position in storage array-based data protection by driving innovations around its product suite. He has filed numerous patents with the US patent office around core storage technologies. Prior to this, Felix worked at Juniper, Novell and IBM, where he handled networking technologies, including LAN, WAN and security protocols and Intrusion Prevention Systems (IPS). Felix has master’s degrees in technology and business administration.

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.


@ThingsExpo Stories
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. 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.
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
SYS-CON Events announced today that Evatronix will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...