RAMCloud: When Disks and Flash Memory are Just Too Slow

By Michael Feldman

October 20, 2011

As storage customers look for a way off the spinning disk merry-go-round, SSDs have become the hottest gadgets in the enterprise. But a team of computer scientists at Stanford University think they can do even better. The researchers have come up with a scalable, high performance storage approach dubbed RAMCloud — RAM because it stores all the data in DRAM, and cloud because it can aggregate the memory resources of a whole datacenter.

The cloud reference also alludes to its main application space in the internet universe of Web page slinging and online database transacting. But the scalability and performance aspect of RAMCloud also makes it a candidate for high performance computing, particularly those applications that swing to the data-intensive, rather than compute-intensive, side of the spectrum.

The RAMCloud project is led by Stanford professor John Ousterhout, inventor of the Tcl scripting language. No stranger to the world of performance computing, Ousterhout’s research work has delved into, among other things, distributed operating systems and high-performance file systems. Outside of the academic sphere, he serves as the chairman of Electric Cloud Inc., a company he founded in 2002 to provide high-performance software build tools.

In a nutshell, RAMCloud is a software platform that aggregates the memory of a large number of commodity servers to host all the application data in a datacenter or cluster. Since DRAM is being used, RAMCloud is said to deliver 100-1000x lower latency than disk-based storage and 100-1000x greater throughput. The software uses a combination of replication and backup techniques to deal with the fact that DRAM drops all its bits when power is cut off.

The original RAMCloud design was described in detail in a 2009 and is encapsulated in a recent article in the Communications of the ACM. The researchers are convinced that the current reliance on hard disk technology will not suffice for data-intensive applications, which are quickly spreading into every aspect of enterprise computing. As the researchers proclaim in the article, “if RAMCloud succeeds, it will probably displace magnetic disk as the primary storage technology in data centers.”
 
The two most important attributes of RAMCloud is its ability to scale across thousands of server and its extremely low latency and. Regarding the latter, we are talking latencies on the order of 5-10 µs, which is 1,000 times faster than disk and about 5 times faster than flash. The researchers admit this level of latency is probably overkill for any current Web-based applications, but should encourage new applications that would take advantage of such performance. (Of course, for some HPC applications, single-digit microsecond latencies would be greatly appreciated today.)

Unfortunately, network latency is going to impinge on the aggregate latency of a RAMCloud set up. While the researchers recognized that low-latency networks such as InfiniBand, Myrinet, and high performance Ethernet from vendors like Arista, can achieve 10µs latencies across a datacenter, most facilities today employ TCP/IP on top of Ethernet, which provide typical round-trips on the order of 300µs–500µs. Optimizing these networks in regard to latency will be key to maximizing RAMCloud performance.

As far as scalability is concerned, using today’s commodity server and memory technology, the researchers think RAMClouds as large as 500 TB can be constructed. At current memory prices, RAMCloud storage would cost around $60/GB. Within 5 to 10 years, they predict it will be possible to build RAMClouds as large as 1 to 10 petabytes at a cost of under $5/GB.

Of course, DRAM-base storage is always likely to be more expensive than disks or solid state storage. At current pricing a DRAM storage system is about 50-100 time more costly than a disk-based set up and 5 to 10 time more costly than a flash memory system. But for high throughput I/O applications, such prices are easier to justify. The researchers argue that if your code’s execution is bound by how fast you can access data in storage, DRAM can actually be 10 to 100 times less expensive than disk.

There are a number of issues that are still to be worked out with the technology, including the exact data model and API, how to optimize latency in regard to remote procedure calls, data durability and availability, cluster management, application multi-tenancy, and support for atomic updates. Nevertheless, these are all solvable issues.

With the ongoing buildup of scaled-out datacenters, along with the emergence of data-intensive applications, much of the groundwork for RAMCloud is already being laid. No timeline has been offered to turn the RAMCloud research project into a commercial offering, but there don’t appear to be any technological showstoppers. And given Ousterhout’s entrepreneurial experience with Electric Cloud, a startup may not be too far off.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

Pfizer HPC Engineer Aims to Automate Software Stack Testing

January 17, 2019

Seeking to reign in the tediousness of manual software testing, Pfizer HPC Engineer Shahzeb Siddiqui is developing an open source software tool called buildtest, aimed at automating software stack testing by providing the community with a central repository of tests for common HPC apps and the ability to automate execution of testing. Read more…

By Tiffany Trader

Senegal Prepares to Take Delivery of Atos Supercomputer

January 16, 2019

In just a few months time, Senegal will be operating the second largest HPC system in sub-Saharan Africa. The Minister of Higher Education, Research and Innovation Mary Teuw Niane made the announcement on Monday (Jan. 14 Read more…

By Tiffany Trader

Google Cloud Platform Extends GPU Instance Options

January 16, 2019

If it's Nvidia GPUs you're after to power your AI/HPC/visualization workload, Google Cloud has them, now claiming "broadest GPU availability." Each of the three big public cloud vendors has by turn touted the latest and Read more…

By Tiffany Trader

HPE Extreme Performance Solutions

HPE Systems With Intel Omni-Path: Architected for Value and Accessible High-Performance Computing

Today’s high-performance computing (HPC) and artificial intelligence (AI) users value high performing clusters. And the higher the performance that their system can deliver, the better. Read more…

IBM Accelerated Insights

Resource Management in the Age of Artificial Intelligence

New challenges demand fresh approaches

Fueled by GPUs, big data, and rapid advances in software, the AI revolution is upon us. Read more…

STAC Floats ML Benchmark for Financial Services Workloads

January 16, 2019

STAC (Securities Technology Analysis Center) recently released an ‘exploratory’ benchmark for machine learning which it hopes will evolve into a firm benchmark or suite of benchmarking tools to compare the performanc Read more…

By John Russell

Google Cloud Platform Extends GPU Instance Options

January 16, 2019

If it's Nvidia GPUs you're after to power your AI/HPC/visualization workload, Google Cloud has them, now claiming "broadest GPU availability." Each of the three Read more…

By Tiffany Trader

STAC Floats ML Benchmark for Financial Services Workloads

January 16, 2019

STAC (Securities Technology Analysis Center) recently released an ‘exploratory’ benchmark for machine learning which it hopes will evolve into a firm benchm Read more…

By John Russell

A Big Data Journey While Seeking to Catalog our Universe

January 16, 2019

It turns out, astronomers have lots of photos of the sky but seek knowledge about what the photos mean. Sound familiar? Big data problems are often characterize Read more…

By James Reinders

Intel Bets Big on 2-Track Quantum Strategy

January 15, 2019

Quantum computing has lived so long in the future it’s taken on a futuristic life of its own, with a Gartner-style hype cycle that includes triggers of innovation, inflated expectations and – though a useful quantum system is still years away – anticipatory troughs of disillusionment. Read more…

By Doug Black

IBM Quantum Update: Q System One Launch, New Collaborators, and QC Center Plans

January 10, 2019

IBM made three significant quantum computing announcements at CES this week. One was introduction of IBM Q System One; it’s really the integration of IBM’s Read more…

By John Russell

IBM’s New Global Weather Forecasting System Runs on GPUs

January 9, 2019

Anyone who has checked a forecast to decide whether or not to pack an umbrella knows that weather prediction can be a mercurial endeavor. It is a Herculean task: the constant modeling of incredibly complex systems to a high degree of accuracy at a local level within very short spans of time. Read more…

By Oliver Peckham

The Case Against ‘The Case Against Quantum Computing’

January 9, 2019

It’s not easy to be a physicist. Richard Feynman (basically the Jimi Hendrix of physicists) once said: “The first principle is that you must not fool yourse Read more…

By Ben Criger

The Deep500 – Researchers Tackle an HPC Benchmark for Deep Learning

January 7, 2019

How do you know if an HPC system, particularly a larger-scale system, is well-suited for deep learning workloads? Today, that’s not an easy question to answer Read more…

By John Russell

Quantum Computing Will Never Work

November 27, 2018

Amid the gush of money and enthusiastic predictions being thrown at quantum computing comes a proposed cold shower in the form of an essay by physicist Mikhail Read more…

By John Russell

Cray Unveils Shasta, Lands NERSC-9 Contract

October 30, 2018

Cray revealed today the details of its next-gen supercomputing architecture, Shasta, selected to be the next flagship system at NERSC. We've known of the code-name "Shasta" since the Argonne slice of the CORAL project was announced in 2015 and although the details of that plan have changed considerably, Cray didn't slow down its timeline for Shasta. Read more…

By Tiffany Trader

Summit Supercomputer is Already Making its Mark on Science

September 20, 2018

Summit, now the fastest supercomputer in the world, is quickly making its mark in science – five of the six finalists just announced for the prestigious 2018 Read more…

By John Russell

AMD Sets Up for Epyc Epoch

November 16, 2018

It’s been a good two weeks, AMD’s Gary Silcott and Andy Parma told me on the last day of SC18 in Dallas at the restaurant where we met to discuss their show news and recent successes. Heck, it’s been a good year. Read more…

By Tiffany Trader

The Case Against ‘The Case Against Quantum Computing’

January 9, 2019

It’s not easy to be a physicist. Richard Feynman (basically the Jimi Hendrix of physicists) once said: “The first principle is that you must not fool yourse Read more…

By Ben Criger

US Leads Supercomputing with #1, #2 Systems & Petascale Arm

November 12, 2018

The 31st Supercomputing Conference (SC) - commemorating 30 years since the first Supercomputing in 1988 - kicked off in Dallas yesterday, taking over the Kay Ba Read more…

By Tiffany Trader

Contract Signed for New Finnish Supercomputer

December 13, 2018

After the official contract signing yesterday, configuration details were made public for the new BullSequana system that the Finnish IT Center for Science (CSC Read more…

By Tiffany Trader

Nvidia’s Jensen Huang Delivers Vision for the New HPC

November 14, 2018

For nearly two hours on Monday at SC18, Jensen Huang, CEO of Nvidia, presented his expansive view of the future of HPC (and computing in general) as only he can do. Animated. Backstopped by a stream of data charts, product photos, and even a beautiful image of supernovae... Read more…

By John Russell

Leading Solution Providers

SC 18 Virtual Booth Video Tour

Advania @ SC18 AMD @ SC18
ASRock Rack @ SC18
DDN Storage @ SC18
HPE @ SC18
IBM @ SC18
Lenovo @ SC18 Mellanox Technologies @ SC18
NVIDIA @ SC18
One Stop Systems @ SC18
Oracle @ SC18 Panasas @ SC18
Supermicro @ SC18 SUSE @ SC18 TYAN @ SC18
Verne Global @ SC18

HPE No. 1, IBM Surges, in ‘Bucking Bronco’ High Performance Server Market

September 27, 2018

Riding healthy U.S. and global economies, strong demand for AI-capable hardware and other tailwind trends, the high performance computing server market jumped 28 percent in the second quarter 2018 to $3.7 billion, up from $2.9 billion for the same period last year, according to industry analyst firm Hyperion Research. Read more…

By Doug Black

House Passes $1.275B National Quantum Initiative

September 17, 2018

Last Thursday the U.S. House of Representatives passed the National Quantum Initiative Act (NQIA) intended to accelerate quantum computing research and developm Read more…

By John Russell

HPC Reflections and (Mostly Hopeful) Predictions

December 19, 2018

So much ‘spaghetti’ gets tossed on walls by the technology community (vendors and researchers) to see what sticks that it is often difficult to peer through Read more…

By John Russell

Intel Confirms 48-Core Cascade Lake-AP for 2019

November 4, 2018

As part of the run-up to SC18, taking place in Dallas next week (Nov. 11-16), Intel is doling out info on its next-gen Cascade Lake family of Xeon processors, specifically the “Advanced Processor” version (Cascade Lake-AP), architected for high-performance computing, artificial intelligence and infrastructure-as-a-service workloads. Read more…

By Tiffany Trader

Germany Celebrates Launch of Two Fastest Supercomputers

September 26, 2018

The new high-performance computer SuperMUC-NG at the Leibniz Supercomputing Center (LRZ) in Garching is the fastest computer in Germany and one of the fastest i Read more…

By Tiffany Trader

Houston to Field Massive, ‘Geophysically Configured’ Cloud Supercomputer

October 11, 2018

Based on some news stories out today, one might get the impression that the next system to crack number one on the Top500 would be an industrial oil and gas mon Read more…

By Tiffany Trader

Microsoft to Buy Mellanox?

December 20, 2018

Networking equipment powerhouse Mellanox could be an acquisition target by Microsoft, according to a published report in an Israeli financial publication. Microsoft has reportedly gone so far as to engage Goldman Sachs to handle negotiations with Mellanox. Read more…

By Doug Black

The Deep500 – Researchers Tackle an HPC Benchmark for Deep Learning

January 7, 2019

How do you know if an HPC system, particularly a larger-scale system, is well-suited for deep learning workloads? Today, that’s not an easy question to answer Read more…

By John Russell

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This