I didn't get interested in virtualization until pretty recently. Earlier this year I had a long conversation with Serguei Beloussov from SWSoft. He said virtualization is the future; I said the entry barrier against Virtuozzo adoption seems unreasonably high. If you consider the licensing costs/learning curve on one hand, and the availability of cheaper/better hardware on the other, I wasn't sure the math worked out. But since then...
* The launch of Amazon EC2 made a huge splash in the media and among developers, who rave about the convenience of on-demand virtual server instances with standardized machine images. Much easier than deploying and configuring physical equipment!
* I met 3tera through Nicholas Carr's "software kills hardware" blog post. The company's AppLogic grid operating system allows users to deploy, scale, copy, migrate or backup entire applications with one single command (!) by packaging web/app/db/storage infrastructure into one single logical entity. (I joined the company's advisory board a few weeks ago.)
* The Las Vegas Water Valley District enjoyed seamless disaster recovery because its DNS and domain controllers ran on virtualized infrastructure. Thank goodness for VMWare, said the agency's sysadmins. VMWare turns a server into a file. Because it's just a file, you can copy and deploy it as needed.
* And last but not least, ArvatoMobile won InfoWorld's Top 100 IT Projects Award for betting its server farm on Virtuozzo. The company's entire infrastructure runs on 600 virtual servers. It's also virtualized several hundred TBs of storage into a single file system namespace.
I think these new developments are really, really exciting. So I couldn't believe it when Lance Crosby from SoftLayer mentioned that he thinks the dedicated servers market will survive. How? Why? Who wants the hassle of managing individual machines that are each a single point of failure??
As it turns out, AlertLogic does. (Note: the company's infrastructure consists of several islands of server grids where processing nodes share the load; in its case there's no single point of failure.) According to Misha Govshteyn's blog post from yesterday:
"We know enough about the characteristics of our software that we can tell you with a high degree of accuracy the exact disk I/O, dedicated PCI bus bandwidth, network interrupt needs and even which compiler to use for each component to maximize performance.
While we've considered virtualization, we walked away from the idea every time. Fine tuning hardware resources to each software component and ensuring that your architecture can linearly scale requires a great deal of control. Our architecture encourages the most efficient use of highly distributed, but dedicated, servers and introducing a virtualization layer would only create resource contention. The performance tax of VMware or Xen just doesn't justify the benefits in our case."
The moral of the story is, I've got a lot of learning to do. As does every hosting provider, I think, so as to help customers make well-informed decisions between the pros (such as what the Las Vegas Water Valley District enjoyed) and cons (which AlertLogic is looking to avoid) of virtualization.
PS - Rackspace, for one, has given a lot of thought to this issue. I got an email from Lew Moorman as I was typing this post: "Virtualization will make servers easier to manage, more flexible and more powerful. But don't focus too hard on the idea that they'll go away. They won't." Thanks, Lew! :)
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Comment by Anonymous on Tuesday, December 19, 2006
I think both have good points and bad points - but in the long run I don't think it matters. Regular people don't care how they get the hosting or what happens on the back end - they just want to be able to install a script or service and get it to work.
Comment by Anonymous on Tuesday, December 19, 2006
Hi Mitch, "Regular people" don't install scripts :) Regular people have no clue what FTP is, much less PHP, Perl, SSI or MySQL. Or virtualization. On the other hand, I think most developers and experienced site admins do care about the infrastructure they're running on, especially if their application is mission critical. But where virtualization makes the most difference is large-scale apps and enterprise IT. I was reading earlier that the IMF increased its server utilization from 5% to 60% with VMWare - that must have produced very significant cost savings. And the US Open's website went from 60 servers to 9 despite increased traffic. So I'd have to argue that it matters a great deal.
Comment by Anonymous on Tuesday, December 19, 2006
Here's my 2 cents :)
1. Virtualization != Virtuozzo, even though SWSoft wishes us to think this way :) Thus the argument on "entry barrier" does not really apply, as "licensing cost" applies only to Virtuozzo (though VMWare is even more expensive). Learning curve is not a big deal. If you need sysadmins to manage your dedicated servers, they should have no problem learning how Virtuozzo and other virtualization technology works within days.
On the other hand you also have lots of open source/free software virtualization technology all the way from OS-level jail (OpenVZ, Linux VServer), Hypervisor (Xen) to system emulation (QEmu). No licensing cost here, many are proven solutions, and commercial support is also available :)
2. There might be some software solutions that need "high degree of accuracy the exact disk I/O, dedicated PCI bus bandwidth, network interrupt", but I can assure you that these things are rare and in many cases can be compensated by clustering virtualized servers.
There is certainly performance tax on VMWare, Xen and even Virtuozzo, but as the processors get faster and faster, more hardware support right inside the CPU, the penalty is often negligible.
On the other hand I don't think people go with virtualization for "performance". It's about server consolidation. Better resource utilization. Faster deployment. With real-time migration you also get better availability. Companies save more money this way, and the amount saved can get them better hardware, thus compensate any loose of performance.
3. Dedicated servers certainly won't go away. For one thing, all virtual servers still need to run on dedicated physical servers...
Comment by Anonymous on Tuesday, December 19, 2006
Well, by regular folks - I mean more of the type that are hosting customers or soon to be customers. ;)
If you can prove that it can give people better performance at a lower cost - it will be a piece of cake. I think reliability and having it "prove" itself might take some time though as well.
Comment by Anonymous on Tuesday, December 19, 2006
Isabel,
I think some of my post got misparsed. I didn't say we have single points of failure. On the contrary, our infrastructure is composed of several islands of server grids where processing nodes share the load and give us no single points of failure.
What I did say was that I saw no point in virtualizing those grid nodes. As Scott Yang mentioned in one of the comments, virtualization primarily helps you use more of your idle servers. I don't have any underutilized servers, in fact I add dedicated nodes to our clusters to make sure I have adequate headroom to accommodate spikes in demand. Virtualizing my infrastructure seems unnecessary.
Our environment is different than general IT shops, where applications have multiple owners and developers that wrote more of the software are long gone. When you have little control over your software, the administrative benefits of VMware become much more compelling. But again, I don't have that problem.
Misha
Comment by Anonymous on Tuesday, December 19, 2006
Misha - Sorry! Very poor phrasing on my part. I did not mean to imply that your system wasn't fault tolerant. Note added to post.
Mitch - I disagree. The average web hosting customer/prospect is not as web savvy as you. Many local businesses in my neighborhood have/want to build websites, but I can't imagine them installing scripts - ever! They're all about WYSIWYG site builders.
Scott - Great OpenVZ post on your blog! No, Virtuozzo is most certainly not the only virtualization product. I used it as an example because it's the first one I came across. I was involved with EV1's Virtuozzo rollout back in 2004. Deploying/adoption wasn't entirely seamless, both customers and the support staff found the learning curve steeper than expected. Based on that initial experience, I wrote off virtualization as a concept, thinking it'd be easier if people stuck with using physical servers. That was the wrong conclusion, which doesn't mean Virtuozzo is the only right solution :)