Welcome!

Apache Authors: Pat Romanski, Liz McMillan, Elizabeth White, John Mertic, Janakiram MSV

Related Topics: Java IoT, Industrial IoT, Adobe Flex, Machine Learning , Recurring Revenue, Apache

Java IoT: Blog Feed Post

Debunking DRAM vs. Flash Controversy vis-a-vis In-Memory Processing

“Minimal” Performance Advantage of DRAM vs SSD

Wikibon produced an interesting material (looks like paid by Aerospike, NoSQL database recently emerged by resurrecting failed CitrusLeaf and acquihiring AlchemyDB, which product, of course, was recommended in the end) that compares NoSQL databases based on storing data in flash-based SSD vs. storing data in DRAM.

There are number of factual problems with that paper and I want to point them out.

Note that Wikibon doesn’t mention GridGain in this study (we are not a NoSQL datastore per-se after all) so I don’t have any bone in this game other than annoyance with biased and factually incorrect writing.

“Minimal” Performance Advantage of DRAM vs SSD
The paper starts with a simple statement “The minimal performance disadvantage of flash, relative to main memory…”. Minimal? I’ve seen number of studies where performance difference between SSDs and DRAM range form 100 to 10,000 times. For example, this University of California, Berkeley study claims that SSD bring almost no advantage to the Facebook Hadoop cluster and DRAM pre-caching is the way forward.

Let me provide even shorter explanation. Assuming we are dealing with Java – SSD devices are visible to Java application as typical block devices, and therefore accessed as such. It means that a typical object read from such device involves the same steps as reading this object from a file: hardware I/O subsystem, OS I/O subsystem, OS buffering, Java I/O subsystem & buffering, Java deserialization and induced GC. And… if you read the same object from DRAM – it involves few bytecode instructions – and that’s it.

Native C/C++ apps (like MongoDB) can take a slightly quicker route with memory mapped files (or various other IPC methods) – but the performance increase will not be significant (for obvious reason of needing to read/swap the entire pages vs. single object access pattern in DRAM).

Yet another recent technical explanation of the disadvantages of SSD storage can be found here (talking about Oracle’s “in-memory” strategy).

MongoDB, Cassandra, CouchDB DRAM-based?
Amid all the confusion on this topic it’s no wonder the author got it wrong. Neither MongoDB, Cassandra or CouchDB are in-memory systems. They are disk-based systems with support for memory caching. There’s nothing wrong with that and nothing new – every database developed in the last 25 years naturally provides in-memory caching to augment it’s main disk storage.

The fundamental difference here is that in-memory data systems like GridGain, SAP HAHA, GigaSpaces, GemFire, SqlFire, MemSQL, VoltDB, etc. use DRAM (memory) as the main storage medium and use disk for optional durability and overflow. This focus on RAM-based storage allows to completely re-optimized all main algorithms used in these systems.

For example, ACID implementation in GridGain that provides support for full-featured distributed ACID transactions beats every NoSQL database (EC-based) out there in read and even write performance: there are no single key limitations, no consistency trade offs to make, no application-side MVCC, no user-based conflict resolutions or other crutches – it just works the same way as it works in Oracle or DB2 – but faster.

2TB Cluster for $1.2M :)
If there was on piece in the original paper that was completely made up to fit the predefined narrative it was a price comparison. If the author thinks that 2TB RAM cluster costs $1.2M today – I have not one but two Golden Gate bridges to sell just for him…

Let’s see. A typical Dell/HP/IBM/Cisco blade with 256GB of DRAM will cost below $20K if you just buy on the list prices (Cisco seems to offer the best prices starting at around $15K for 256GB blades). That brings the total cost of 2TB cluster well below $200K (with all network and power equipment included and 100s TBs of disk storage).

Is this more expensive that SSD only cluster? Yes, by 2.5-3x times more expensive. But you are getting dramatic performance increase with the right software that more than justifies that price increase.

Conclusion
2-3x times price difference is nonetheless important and it provides our customers a very clear choice. If price is an issue and high performance is not – there are disk-based systems of wide varieties. If high performance and sub-second response on processing TBs of data is required – the hardware will be proportionally more expensive.

However, with 1GB of DRAM costing less than 1 USD and DRAM prices dropping 30% every 18 months – the era of disks (flash or spinning) is clearly coming to its logical end. It’s normal… it’s a progress and we all need to learn how to adapt.

Has anyone seen tape drives lately?

Read the original blog entry...

More Stories By Thomas Krafft

Over 15 years of experience in marketing and demand creation, with strategies driving over $500 million in revenue for a variety of companies in several high-growth and competitive markets, including consumer software and web services, ecommerce, demand creation through web and search, big data, and now healthcare.

@ThingsExpo Stories
Providing secure, mobile access to sensitive data sets is a critical element in realizing the full potential of cloud computing. However, large data caches remain inaccessible to edge devices for reasons of security, size, format or limited viewing capabilities. Medical imaging, computer aided design and seismic interpretation are just a few examples of industries facing this challenge. Rather than fighting for incremental gains by pulling these datasets to edge devices, we need to embrace the i...
Web Real-Time Communication APIs have quickly revolutionized what browsers are capable of. In addition to video and audio streams, we can now bi-directionally send arbitrary data over WebRTC's PeerConnection Data Channels. With the advent of Progressive Web Apps and new hardware APIs such as WebBluetooh and WebUSB, we can finally enable users to stitch together the Internet of Things directly from their browsers while communicating privately and securely in a decentralized way.
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).
SYS-CON Events announced today that Catchpoint, a leading digital experience intelligence company, has been named “Silver Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Catchpoint Systems is a leading Digital Performance Analytics company that provides unparalleled insight into your customer-critical services to help you consistently deliver an amazing customer experience. Designed for digital business, C...
@ThingsExpo has been named the ‘Top WebRTC Influencer' by iTrend. iTrend processes millions of conversations, tweets, interactions, news articles, press releases, blog posts - and extract meaning form them and analyzes mobile and desktop software platforms used to communicate, various metadata (such as geo location), and automation tools. In overall placement, @ThingsExpo ranked as the number one ‘WebRTC Influencer' followed by @DevOpsSummit at 55th.
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices 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 business opportunity. Submit your speaking proposal ...
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, 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.
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
In the next five to ten years, millions, if not billions of things will become smarter. This smartness goes beyond connected things in our homes like the fridge, thermostat and fancy lighting, and into heavily regulated industries including aerospace, pharmaceutical/medical devices and energy. “Smartness” will embed itself within individual products that are part of our daily lives. We will engage with smart products - learning from them, informing them, and communicating with them. Smart produc...
"What is the next step in the evolution of IoT systems? The answer is data, information, which is a radical shift from assets, from things to input for decision making," stated Michael Minkevich, VP of Technology Services at Luxoft, in this SYS-CON.tv interview at @ThingsExpo, held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA.
The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions with...
WebRTC sits at the intersection between VoIP and the Web. As such, it poses some interesting challenges for those developing services on top of it, but also for those who need to test and monitor these services. In his session at WebRTC Summit, Tsahi Levent-Levi, co-founder of testRTC, reviewed the various challenges posed by WebRTC when it comes to testing and monitoring and on ways to overcome them.
Internet of @ThingsExpo, taking place June 6-8, 2017 at the Javits Center in New York City, New York, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo New York Call for Papers is now open.
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, discussed the best practices that will ensure a successful smart city journey.
Every successful software product evolves from an idea to an enterprise system. Notably, the same way is passed by the product owner's company. In his session at 20th Cloud Expo, Oleg Lola, CEO of MobiDev, will provide a generalized overview of the evolution of a software product, the product owner, the needs that arise at various stages of this process, and the value brought by a software development partner to the product owner as a response to these needs.
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, John Jelinek IV, a web developer at Linux Academy, will discuss why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers...
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex softw...
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, explored the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences between wh...