– Lori MacVittie, senior technical marketing manager at F5 Networks (www.f5.com), says:
RFC 1945 – “Hypertext Transfer Protocol — HTTP/1.0” – was published in May 1996. In June of 1999, RFC 2616 – “Hypertext Transfer Protocol — HTTP/1.1” was published. In the ensuing 13 years there has been no substantial changes to the HTTP standard. None. Nada. Zilch.
Even as the size and number of objects has ballooned over that time, and the overall composition of web pages grown increasingly complex, still there’s been no substantial efforts to improve upon the now entrenched HTTP standard. Even as sites struggled to maintain availability and performance in the face of exploding usage growth – fueled by mobile device proliferation, increasingly affordable access enabling everything from plants to cows to users to “get online” – HTTP 1.1 remained the standard for web-everything, despite the growing fact that it simply wasn’t the most optimal means of connecting users with the resources they expect and increasingly, demand.
AJAX and Web 2.0 gave us better interactive models that alleviated some of the pain associated with performance problems, but as that model took hold and video became the medium du jour even its advantages have become unable to produce the acceptable results.
And then Google introduced SPDY. The first shot in the HTTP 2.0 war. Now Microsoft has fired back with “Speed+Mobility” and the battle appears about to be fully engaged.
Although SPDY has been out and about for some time, it only recently made it to the status of “Internet-Draft” in the RFC system, being officially published in Feb 2012. Along comes March 2012, and Microsoft has (sort of) countered with Speed+Mobility.
What will be interesting as the battle progresses is to see which other organizations and vendors will side with which version (if not both). Invariably other organizations will want to be able to claim to have been co-authors of whichever standard becomes, well, the standard but choosing sides so early in a war is hardly appropriate, especially when the technical details are still (as of this writing) missing from Microsoft’s proposal.
RIP-REPLACE versus UPGRADE
It’s also not clear how Speed + Mobility will “retain as much compatibility as possible with the existing Web infrastructure” – a noble and laudable sentiment, to be sure – while still adopting most of the core concepts including in SPDY:
HTTP Speed+Mobility RFC
It [the session layer] would maintain the integrity of the layered architecture.
It would use an upgrade mechanism similar to that of WebSockets.
This would enable compatibility with existing proxies and
connection models, without creating a mandatory dependency on TLS.
[Same as SPDY] The protocol would define two types of frames: data
[Same as SPDY] The session layer would enable negotiation of
multiple simultaneous streams for HTTP requests with minimal
[Same as SPDY] The session layer would allow for prioritizing
delivery of content to ensure highest value traffic is delivered
There’s not much in the Speed + Mobility RFC on which to base a technical impact assessment on infrastructure (existing proxies and other HTTP mediating devices like load balancers) but what Microsoft appears to be saying is that it wants to leverage the concepts introduced by Google with SPDY (acknowledging their performance and ultimately scaling benefits) without leaving the familiar world of HTTP. That’s actually important, assuming it can be done, because SPDY requires significant changes to existing infrastructure – network and server – in order to operate, and it is not inherently interoperable with HTTP.
Despite this, SPDY interest and inquiries are beginning to become more frequent, which means it’s getting the attention it deserves. Being the only kid on the block to really address the performance issues inherent with HTTP (especially with respect to mobile devices) that’s no surprise as the investment in new solutions to support SPDY would ostensibly see a return in the form of scalability on the server side by requiring fewer server resources to support as many if not more users.
But SPDY isn’t so far along (see previous note) as to be a clear front runner. It’s still too new despite interest to have garnered widespread support or mindshare, and despite Google’s ubiquitous status as a household term for search, it isn’t necessarily synonymous with web standards. Chrome may be gaining on IE, but in the minds of most users, IE is still synonymous with web browsing. It also has a serious advantage over Google in its relationship with the enterprise and IT, and in its more intimate understanding of data center infrastructure, as is evident from its blog on the introduction of its proposal:
We think that rapid adoption of HTTP 2.0 is important. To make that happen, HTTP 2.0 needs to retain as much compatibility as possible with the existing Web infrastructure. Awareness of HTTP is built into nearly every switch, router, proxy, Load balancer, and security system in use today. If the new protocol is “HTTP” in name only, upgrading all of this infrastructure would take too long. By building on existing web standards, the community can set HTTP 2.0 up for rapid adoption throughout the web.
Google, while not necessarily openly hostile to the enterprise or infrastructure vendors who’d need to support SPDY, certainly appears indifferent to the impact of a rip-and-replace protocol model.
That’s not to say Google’s approach isn’t feasible or desirable. Indeed, in some cases a “rip-and-replace” strategy is the only way to clean out the cobwebs that otherwise seem to hang onto technology for years after they’ve been superceded and superceded again. Think COBOL, which in some industries is still under active development, augmented by a hundred other technologies designed to workaround the reality that it’s an aged, outdated technology that for various reasons we are unable to simply walk away from.
TAKE a SIDE ALREADY, WILL YOU?!
Nope. Not gonna take a side yet – if ever. Personal preferences aside (which it’s hard to have at this point without more technical details from Microsoft) the decision whether an organization eventually wants to go with SPDY or Speed+Mobility will not at all impact negatively mediating devices. In fact, the existence of both would not negatively impact such devices because of their strategic location in the network. The existence of all three – SPDY, S+M, HTTP – would actually not negatively impact these devices as long as they were able to support all three, which seems more likely than simply choosing a side.
There will be a need to support both – and likely all three (do I hear a fourth?) – protocols moving forward. Regardless of who wins this particular war and comes out crowned HTTP 2.0 champion, there will still be a need to implement support across infrastructure vendors. There will be a transitory period during which browsers and servers and infrastructure all must “get up to speed” (ha!) and will do so at different rates, making the need for intermediating devices critical. Just as is the case with the migration from IPv4 to IPv6, intermediating application delivery solutions provide the means by which organizations with substantial infrastructure investments to maintain the value of those investments while moving forward to support emerging standards.
Being able to translate, for example, between SPDY and HTTP today would be a significant boon for organizations, as it requires no changes to what is likely an extensive application and server infrastructure. Similarly, assuming a pilot of Speed+Mobility, if the application delivery tier can support it, it can mediate – translate – and provide an opportunity to support users via either standard without radically disrupting the application server infrastructure. A full-proxy based application delivery infrastructureis full of advantages, after all.
I like SPDY. I like it’s approach and I actually admire Google’s chutzpah in diverging from HTTP as a solution, recognizing perhaps the inherent tendency to be more concerned with backwards compatibility than with improving upon the model. But I like what Microsoft is saying from an enterprise perspective because honestly, replacing an entire infrastructure architecture to support one protocol out of many is not an appealing option, no matter the benefits.
Both approaches have merit, and the bigger story is that an overhaul of HTTP is necessary – and long overdue.