Welcome!

@BigDataExpo Authors: Nishanth Kadiyala, Liz McMillan, Elizabeth White, Pat Romanski, David H Deans

Blog Feed Post

Big Data Needs a Better Network

Earlier this week I had some interesting conversations with @davehusak. Where the conversation started early in the day with a discussion on overlay networks and what network functions are performed where and in what context, later in the afternoon the discussion moved to networking solutions (and specifically Plexxi solutions) for big data applications.

It’s easy to jump to Hadoop or similarly structured cluster computing applications (Spark, Storm, or a long list of others) as the definition of a big data application. With all its simplicity for the overall distribution of work, Hadoop is a fairly tough network problem to solve if you want to do anything more than “throw bandwidth at the problem”. And when you do throw bandwidth at the problem, the extreme burstiness of the traffic will still significantly drag down the performance of the overall solution. And for many, CPU cycles to reduce the data is not the biggest challenge, storage and movement of data throughout a big data cluster is the biggest pain point. Intel has done a fine job providing compute firepower that far outpaces the evolution of network capacity.

The network plays a significant factor in several stages of a Hadoop solution cycle. It starts with chopping the to-be-analyzed data into chunks and distributing it across the datanodes. Hadoop has a notion of a rack and it has some basic intelligence when placing data and jobs that work on that data. By default the data will be replicated 3 times across at least 2 racks, if racks have been defined. The data to be distributed is easily in the 100s of Gigabytes or even Terabytes, so triple that data is being moved throughout the Hadoop cluster to the datanodes.

Once distributed, the actual Map jobs are launched against that data, these are the tasks that take the data and perform a first pass mapping into (in its most basic form) <key, value> tuples. Again here there is an attempt to have jobs work on local data, where local can be defined as local to the server that has that chunk of data or local to the rack, in an attempt to avoid as much cross rack communication as possible. This is based on the assumption that cross rack communication is much more constrained and aggregated and therefore more prone to congestion and packet loss.

Once the mapper jobs complete their task, the results of the mapping exercise is sent to reducers. Reducers take the <key, value> information and essentially tally the results. This transfer is the most taxing part of a Hadoop cycle on the network. Since most Hadoop mapping jobs run the same function on a similar sized dataset, that first set of mappers will all complete their task at about the same time and will all start sending their results to the same set of reducers, creating 1) a lot of traffic and 2) a lot of traffic to the same set of destinations.  Depending on the amount of data, mappers and compute nodes, this cycle repeats (the next set of mapping jobs are fired off) and at the end of each cycle a very significant spike in network traffic appears. At the very end, all results are brought together for one last spike in traffic. Each one of these network events is a source of significant congestion.

Many variables contribute to the overall performance of the Hadoop solution. What is the relationship between the chunks of data and the amount of servers and jobs? How many reducers are used? Where are the reducers in relation to the mappers? Is the Map function compute heavy or I/O heavy? How aggressive is the speculative scheduling that allows the same data to be worked on by multiple mappers?

With that many variables that can be tuned, and with so many variables different from one analysis to the next, it is hard to imagine that a single network design or implementation provides the best supporting infrastructure. There are assumptions in Hadoop placement of data and jobs that can easily be altered. The basic concept of a rack can easily expanded into a multi layer locality definition. With the right tools in the network, the definition of a rack, or even the locality and closeness of nodes in a cluster or virtual cluster can be adjusted according to the analysis to be completed.

We tend to give our applications variables to tune its performance based on what the network provides. It is time that the network adjusts itself based on the application needs. In a clustered application like Hadoop, there is lots of knowledge and even some predictability of network traffic. Wouldn’t that make for a great opportunity to infuse the network with some of that knowledge and have it morph itself to provide the best possible service? And Hadoop is not unique, cluster compute framework almost all carefully track placement of data and compute jobs, which makes them all great candidates to share some of that information with a smart network.

There are far simpler big data needs and applications that can and should be supported by flexible networks. Storage networks are still often separated from data networks for performance reasons and fear of interference. If you could actually separate the various types of data with logically or even physically different paths in the same network, would you still?

 

[Today's fun fact: An MLB baseball lasts on average 7 pitches. A google search asking how many baseballs are used in a single MLB season returns several pages worth of different answers. They must all be correct, it's on the Internet afterall.]

The post Big Data Needs a Better Network appeared first on Plexxi.

Read the original blog entry...

More Stories By Marten Terpstra

Marten Terpstra is a Product Management Director at Plexxi Inc. Marten has extensive knowledge of the architecture, design, deployment and management of enterprise and carrier networks.

@BigDataExpo Stories
Join us at Cloud Expo June 6-8 to find out how to securely connect your cloud app to any cloud or on-premises data source – without complex firewall changes. More users are demanding access to on-premises data from their cloud applications. It’s no longer a “nice-to-have” but an important differentiator that drives competitive advantages. It’s the new “must have” in the hybrid era. Users want capabilities that give them a unified view of the data to get closer to customers and grow business. The...
Cloud applications are seeing a deluge of requests to support the exploding advanced analytics market. “Open analytics” is the emerging strategy to deliver that data through an open data access layer, in the cloud, to be directly consumed by external analytics tools and popular programming languages. An increasing number of data engineers and data scientists use a variety of platforms and advanced analytics languages such as SAS, R, Python and Java, as well as frameworks such as Hadoop and Spark...
Artificial intelligence, machine learning, neural networks. We’re in the midst of a wave of excitement around AI such as hasn’t been seen for a few decades. But those previous periods of inflated expectations led to troughs of disappointment. Will this time be different? Most likely. Applications of AI such as predictive analytics are already decreasing costs and improving reliability of industrial machinery. Furthermore, the funding and research going into AI now comes from a wide range of com...
The current age of digital transformation means that IT organizations must adapt their toolset to cover all digital experiences, beyond just the end users’. Today’s businesses can no longer focus solely on the digital interactions they manage with employees or customers; they must now contend with non-traditional factors. Whether it's the power of brand to make or break a company, the need to monitor across all locations 24/7, or the ability to proactively resolve issues, companies must adapt to...
"When we talk about cloud without compromise what we're talking about is that when people think about 'I need the flexibility of the cloud' - it's the ability to create applications and run them in a cloud environment that's far more flexible,” explained Matthew Finnie, CTO of Interoute, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 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 software systems for startups and enterprises. Since 2009 it has grown from a small group of passionate engineers and business...
SYS-CON Events announced today that GrapeUp, the leading provider of rapid product development at the speed of business, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market acr...
SYS-CON Events announced today that Ayehu will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara California. Ayehu provides IT Process Automation & Orchestration solutions for IT and Security professionals to identify and resolve critical incidents and enable rapid containment, eradication, and recovery from cyber security breaches. Ayehu provides customers greater control over IT infras...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
21st International Cloud Expo, taking place October 31 - November 2, 2017, 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. Me...
DevOps at Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st 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 w...
In this presentation, Striim CTO and founder Steve Wilkes will discuss practical strategies for counteracting fraud and cyberattacks by leveraging real-time streaming analytics. In his session at @ThingsExpo, Steve Wilkes, Founder and Chief Technology Officer at Striim, will provide a detailed look into leveraging streaming data management to correlate events in real time, and identify potential breaches across IoT and non-IoT systems throughout the enterprise. Strategies for processing massive ...
SYS-CON Events announced today that Cloud Academy named "Bronze Sponsor" of 21st International Cloud Expo which will take place October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara, CA. Cloud Academy is the industry’s most innovative, vendor-neutral cloud technology training platform. Cloud Academy provides continuous learning solutions for individuals and enterprise teams for Amazon Web Services, Microsoft Azure, Google Cloud Platform, and the most popular cloud com...
In his session at Cloud Expo, Alan Winters, an entertainment executive/TV producer turned serial entrepreneur, presented a success story of an entrepreneur who has both suffered through and benefited from offshore development across multiple businesses: The smart choice, or how to select the right offshore development partner Warning signs, or how to minimize chances of making the wrong choice Collaboration, or how to establish the most effective work processes Budget control, or how to ma...
SYS-CON Events announced today that Enzu will exhibit at SYS-CON's 21st Int\ernational Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to focus on the core of their ...
SYS-CON Events announced today that IBM has been named “Diamond Sponsor” of SYS-CON's 21st Cloud Expo, which will take place on October 31 through November 2nd 2017 at the Santa Clara Convention Center in Santa Clara, California.
We build IoT infrastructure products - when you have to integrate different devices, different systems and cloud you have to build an application to do that but we eliminate the need to build an application. Our products can integrate any device, any system, any cloud regardless of protocol," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business - from apparel to energy - is being rewritten by software. From planning to development to management to security, CA creates software that fuels transformation for companies in the applic...