Welcome!

Agile Computing Authors: SmartBear Blog, Elizabeth White, Ferhat Hatay, Liz McMillan, James Carlini

Related Topics: Microservices Expo, Containers Expo Blog, IoT User Interface, @CloudExpo

Microservices Expo: Blog Feed Post

SPDY versus HTML5 WebSockets

SPDY So much alike, yet so vastly a different impact on the data center …

A recent post on the HTTP 2.0 War beginning garnered a very relevant question regarding WebSockets and where it fits in (what might shape up to be) an epic battle.

The answer to the question, “Why not consider WebSockets here?” could be easily answered with two words: HTTP headers. It could also be answered with two other words: infrastructure impact.

But I’m guessing Nagesh (and others) would like a bit more detail on that, so here comes the (computer) science.

Different Solutions Have Different Impacts

websocketquestionDue to a simple (and yet profound) difference between the two implementations, WebSockets is less likely to make an impact on the web (and yet more likely to make an impact inside data centers, but more on that another time). Nagesh is correct in that in almost all the important aspects, WebSockets and SPDY are identical (if not in implementation, in effect). Both are asynchronous, which eliminates the overhead of “polling” generally used to simulate “real time” updates a la Web 2.0 applications. Both use only a single TCP connection. This also reduces overhead on servers (and infrastructure) which can translate into better performance for the end-user. Both can make use of compression (although only via extensions in the case of WebSockets) to reduce size of data transferred resulting, one hopes, in better performance, particularly over more constrained mobile networks.

Both protocols operate “outside” HTTP and use an upgrade mechanism to initiate. While WebSockets uses the HTTP connection header to request an upgrade, SPDY uses the Next Protocol Negotiation (proposed enhancement to the TLS specification). This mechanism engenders better backwards-compatibility across the web, allowing sites to support both next-generation web applications as well as traditional HTTP.

Both specifications are designed, as pointed out, to solve the same problems. And both do, in theory and in practice. The difference lies in the HTTP headers – or lack thereof in the case of WebSockets.

quote-badgeOnce established, WebSocket data frames can be sent back and forth between the client and the server in full-duplex mode. Both text and binary frames can be sent full-duplex, in either direction at the same time. The data is minimally framed with just two bytes. In the case of text frames, each frame starts with a 0x00 byte, ends with a 0xFF byte, and contains UTF-8 data in between. WebSocket text frames use a terminator, while binary frames use a length prefix.

-- HTML5 Web Sockets: A Quantum Leap in Scalability for the Web

WebSockets does not use HTTP headers, SPDY does. This seemingly simple difference has an inversely proportional impact on supporting infrastructure.

The Impact on Infrastructure

The impact on infrastructure is why WebSockets may be more trouble than its worth – at least when it comes to public-facing web applications. While both specifications will require gateway translation services until (if) they are fully adopted, WebSockets has a much harsher impact on the intervening infrastructure than does SPDY.

WebSockets effectively blinds infrastructure. IDS, IPS, ADC, firewalls, anti-virus scanners – any service which relies upon HTTP headers to determine specific content type or location (URI) of the object being requested – is unable to inspect or validate requests due to its lack of HTTP headers. Now, SPDY doesn’t make it easy – HTTP request headers are compressed – but it doesn’t make it nearly as hard, because gzip is pretty well understood and even intermediate infrastructure can deflate and recompress with relative ease (and without needing special data, such as is the case with SSL/TLS and certificates).

Let me stop for a moment and shamelessly quote myself from a blog on this very subject, “Oops! HTML5 Does it Again”:

quote-badgeOne of the things WebSockets does to dramatically improve performance is eliminate all those pesky HTTP headers. You know, things like CONTENT-TYPE. You know, the header that tells the endpoint what kind of content is being transferred, such as text/html and video/avi. One of the things anti-virus and malware scanning solutions are very good at is detecting anomalies in specific types of content. The problem is that without a MIME type, the ability to correctly identify a given object gets a bit iffy. Bits and bytes are bytes and bytes, and while you could certainly infer the type based on format “tells” within the actual data, how would you really know? Sure, the HTTP headers could by lying, but generally speaking the application serving the object doesn’t lie about the type of data and it is a rare vulnerability that attempts to manipulate that value. After all, you want a malicious payload delivered via a specific medium, because that’s the cornerstone upon which many exploits are based – execution of a specific operation against a specific manipulated payload. That means you really need the endpoint to believe the content is of the type it thinks it is.

But couldn’t you just use the URL? Nope – there is no URL associated with objects via a WebSocket. There is also no standard application information that next-generation firewalls can use to differentiate the content; developers are free to innovate and create their own formats and micro-formats, and undoubtedly will. And trying to prevent its use is nigh-unto impossible because of the way in which the upgrade handshake is performed – it’s all over HTTP, and stays HTTP. One minute the session is talking understandable HTTP, the next they’re whispering in Lakota, a traditionally oral-only language which neatly illustrates the overarching point of this post thus far: there’s no way to confidently know what is being passed over a WebSocket unless you “speak” the language used, which you may or may not have access to.

The result of all this confusion is that security software designed to scan for specific signatures or anomalies within specific types of content can’t. They can’t extract the object flowing through a WebSocket because there’s no indication of where it begins or ends, or even what it is. The loss of HTTP headers that indicate not only type but length is problematic for any software – or hardware for that matter – that uses the information contained within to extract and process the data.

SPDY, however, does not eliminate these Very-Important-to-Infrastructure-Services HTTP headers, it merely compresses them. Which makes SPDY a much more compelling option than WebSockets. SPDY can be enabled for an entire data center via the use of a single component: a SPDY gateway. WebSockets ostensibly requires the upgrade or replacement of many more infrastructure services and introduces risks that may be unacceptable to many organizations.

And thus my answer to the question "Why not consider WebSockets here” is simply that the end-result (better performance) of implementing the two may be the same, WebSockets is unlikely to gain widespread acceptance as the protocol du jour for public facing web applications due to the operational burden it imposes on the rest of the infrastructure.

That doesn’t mean it won’t gain widespread acceptance inside the enterprise. But that’s a topic for another day…

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

@ThingsExpo Stories
Companies can harness IoT and predictive analytics to sustain business continuity; predict and manage site performance during emergencies; minimize expensive reactive maintenance; and forecast equipment and maintenance budgets and expenditures. Providing cost-effective, uninterrupted service is challenging, particularly for organizations with geographically dispersed operations.
The Quantified Economy represents the total global addressable market (TAM) for IoT that, according to a recent IDC report, will grow to an unprecedented $1.3 trillion by 2019. With this the third wave of the Internet-global proliferation of connected devices, appliances and sensors is poised to take off in 2016. In his session at @ThingsExpo, David McLauchlan, CEO and co-founder of Buddy Platform, will discuss how the ability to access and analyze the massive volume of streaming data from mil...
WebSocket is effectively a persistent and fat pipe that is compatible with a standard web infrastructure; a "TCP for the Web." If you think of WebSocket in this light, there are other more hugely interesting applications of WebSocket than just simply sending data to a browser. In his session at 18th Cloud Expo, Frank Greco, Director of Technology for Kaazing Corporation, will compare other modern web connectivity methods such as HTTP/2, HTTP Streaming, Server-Sent Events and new W3C event APIs ...
Join us at Cloud Expo | @ThingsExpo 2016 – June 7-9 at the Javits Center in New York City and November 1-3 at the Santa Clara Convention Center in Santa Clara, CA – and deliver your unique message in a way that is striking and unforgettable by taking advantage of SYS-CON's unmatched high-impact, result-driven event / media packages.
SYS-CON Events announced today that FalconStor Software® Inc., a 15-year innovator of software-defined storage solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. FalconStor Software®, Inc. (NASDAQ: FALC) is a leading software-defined storage company offering a converged, hardware-agnostic, software-defined storage and data services platform. Its flagship solution FreeStor®, utilizes a horizonta...
Silver Spring Networks, Inc. (NYSE: SSNI) extended its Internet of Things technology platform with performance enhancements to Gen5 – its fifth generation critical infrastructure networking platform. Already delivering nearly 23 million devices on five continents as one of the leading networking providers in the market, Silver Spring announced it is doubling the maximum speed of its Gen5 network to up to 2.4 Mbps, increasing computational performance by 10x, supporting simultaneous mesh communic...
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, will provide an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data profes...
Eighty percent of a data scientist’s time is spent gathering and cleaning up data, and 80% of all data is unstructured and almost never analyzed. Cognitive computing, in combination with Big Data, is changing the equation by creating data reservoirs and using natural language processing to enable analysis of unstructured data sources. This is impacting every aspect of the analytics profession from how data is mined (and by whom) to how it is delivered. This is not some futuristic vision: it's ha...
With the Apple Watch making its way onto wrists all over the world, it’s only a matter of time before it becomes a staple in the workplace. In fact, Forrester reported that 68 percent of technology and business decision-makers characterize wearables as a top priority for 2015. Recognizing their business value early on, FinancialForce.com was the first to bring ERP to wearables, helping streamline communication across front and back office functions. In his session at @ThingsExpo, Kevin Roberts...
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
One of the bewildering things about DevOps is integrating the massive toolchain including the dozens of new tools that seem to crop up every year. Part of DevOps is Continuous Delivery and having a complex toolchain can add additional integration and setup to your developer environment. In his session at @DevOpsSummit at 18th Cloud Expo, Miko Matsumura, Chief Marketing Officer of Gradle Inc., will discuss which tools to use in a developer stack, how to provision the toolchain to minimize onboa...
With an estimated 50 billion devices connected to the Internet by 2020, several industries will begin to expand their capabilities for retaining end point data at the edge to better utilize the range of data types and sheer volume of M2M data generated by the Internet of Things. In his session at @ThingsExpo, Don DeLoach, CEO and President of Infobright, will discuss the infrastructures businesses will need to implement to handle this explosion of data by providing specific use cases for filte...
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies adopt disruptive technologies to optimize revenue-generating systems, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advanced analytics, and DevO...
SYS-CON Events announced today that Avere Systems, a leading provider of enterprise storage for the hybrid cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Avere delivers a more modern architectural approach to storage that doesn’t require the overprovisioning of storage capacity to achieve performance, overspending on expensive storage media for inactive data or the overbuilding of data centers ...
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 ad...
SYS-CON Events announced today that Men & Mice, the leading global provider of DNS, DHCP and IP address management overlay solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. The Men & Mice Suite overlay solution is already known for its powerful application in heterogeneous operating environments, enabling enterprises to scale without fuss. Building on a solid range of diverse platform support,...
Fortunately, meaningful and tangible business cases for IoT are plentiful in a broad array of industries and vertical markets. These range from simple warranty cost reduction for capital intensive assets, to minimizing downtime for vital business tools, to creating feedback loops improving product design, to improving and enhancing enterprise customer experiences. All of these business cases, which will be briefly explored in this session, hinge on cost effectively extracting relevant data from ...
There will be new vendors providing applications, middleware, and connected devices to support the thriving IoT ecosystem. This essentially means that electronic device manufacturers will also be in the software business. Many will be new to building embedded software or robust software. This creates an increased importance on software quality, particularly within the Industrial Internet of Things where business-critical applications are becoming dependent on products controlled by software. Qua...