Web Informant #247, 3 May 2001:
Serving up spare slots


You can never be too rich, too thin, nor have too many application servers to run your business. And a new company is trying to help you over that last hurdle, perhaps along the way trimming some of the computing fat and delivering a better return on your PC investment. The company, OmniCluster Technologies Inc., has a new way to harness the power of your existing computers with their SlotServer product.

[FULL DISCLOSURE: I did some consulting work for the company this past week, and came away very impressed with the product. See the end of this essay.]

These days, the average web-savvy business needs lots of servers to thrive. Besides the ordinary web server, you need a server to handle credit card processing, management and personalization of your content, servers to balance your loads, keep track of your banner ad clickthroughs and cache your pages, firewalls to protect your network resources and so forth. To get an idea of how complex this has gotten, eCompany Now magazine lists over 20 different servers and services required to set up today's modern web-oriented business -- that is a lot of software to manage.

In the past, that meant installing and setting up separate machines for many of these processes, or figuring out ways that a PC could run more than one service reliably.

But that is old-style thinking, so 1998, as some of my friends might say. To get with the current century, OmniCluster shows you a better way with their revolutionary product. Their SlotServer is a complete PC on a half-sized PCI card that fits inside any Intel computer running Linux or Windows 2000. The card comes with its own 300 MHz Intel- compatible processor, two Ethernet interfaces, an IDE disk drive connector, a VGA connector, and a USB port for keyboard and mouse, along with the necessary software drivers to make it all work. It really is a complete computer crammed into a card, and moreover a card that consumes a miserly 10 watts of power. The beauty is you can harvest your spare slots on your existing computersnd install multiple SlotServers in them to multiply the processing power and leverage your existing computing infrastructure, all at very minimal incremental cost.

The SlotServer isn't a network computer, nor is it some strange Windows Terminal rig. It is a real machine, with its own resources and peripherals in every sense of these terms. Indeed, if you have the right kind of PC, such as the Dell Optiplex units that I used for my tests, then your SlotServers can still be running while you reboot the main PC that they are installed in. That is a pretty neat trick, and one that anyone running a data center -- especially an Internet applications-oriented data center -- can appreciate.

The hardest part about the product is installation, and deciding on which of various operating modes to run it in. The Linux path is by far the easiest choice. I was able, with some prompting and assistance (since I am far from Linux- capable), to install a new version of Red Hat 7.0 on a IDE disk attached to the card and be up and running in a matter of an hour. Most of that time was spent copying the operating system distribution files from the CD. No additional patches were required, and other than doing some minor editing of a few configuration files, things went smoothly.

Windows was another matter entirely. You can choose to run your Windows operating system from a directly attached disk drive to the SlotServer, or make use of room on your existing PC disks. (For the latter option, this is similar to what VMware does, although SlotServer sets up a completely separate machine apart from sharing the actual physical disk drive.) You'll also need to install whatever version of Windows from your operating system CD-ROM, and that took several hours to complete.

The instructions are rather complex, since you have to switch back and forth between your existing PC keyboard and screen and the new SlotServer keyboard and screen that you are setting up, along with rebooting several times as you build up your new system. The supplied documentation came with several errors, along with a few confusing twists and turns where I needed to get help from the vendor. And once you bring up your SlotServer version of Windows, you'll notice a few unsettling configuration errors reported in the System Device Manager Control Panel. Unfortunately, these aren't problems with your actual hardware configuration but are expected and part of the normal operations of the product, an unfortunate circumstance but nothing more than annoying. Hopefully, most of these problems will be fixed soon.

Once you set up one SlotServer, adding others to the same machine running the same OS versions is a piece of cake and literally takes a few minutes, with either Windows or Linux. Right now you can only run Windows variations on Windows machines, and Linux on Linux, although the company is working on mixed-mode versions for the near future. The company has tested up to seven SlotServers installed in one machine: given that their designs supports hundreds of them installed in one machine, you'll obviously run out of spare PCI slots or bump against the limitations of your power supply. That is a very comforting thought, and a reminder that there is plenty of horsepower in those beige boxes that can be taken advantage of, if the right product comes along to do so.

You'll notice I mentioned that the product comes with two Ethernet interfaces. This is the beauty of the product, and one that will have direct consequences for web application developers. Yes, the SlotServer has its own RJ45 Ethernet jack out the back, and you can connect this to your hub or switch in the usual fashion. But the second network interface is actually the one you want to use for your applications to communicate with each other, because it operates much faster. (I didn't get a chance to accurately test this, but would guess that it could approach gigabit speeds.) This second interface actually communicates across the PCI bus of the main computer. It has its own IP address, but there aren't any cables to install, switches to maintain, or anything else to worry about.

If you have a bunch of SlotServers installed in a single PC, you have the makings of a very powerful web applications engine, with each SlotServer dedicated to a particular task or service. The nice thing about this setup is that it is perfect for your treasured web applications and services, since it is a completely protected private network, not accessible from the big, bad outside world of the public Internet. Essentially, you get this for free as part of the product, and it is an important concept to grasp. This means if you have a series of SlotServers, each one running a particular piece of your web applications infrastructure, you can have them communicating with each other without having to make a single modification to them. As far as they are concerned, they are running on independent PCs and working across a regular IP network -- a network that isn't visible to the outside world.

Overall, this is a product that makes sense from several perspectives. If you are designing a new high-density computing environment, such as a server farm, a call center or computer classroom, then SlotServer will help you deliver your PCs at lower total ownership cost and significant power savings. If you need to add servers to your existing Internet data center and don't have the rack space to spare, then look to harvest your slots on your current crop of servers. And if you are nervous running multiple Windows application servers on the same machine, then you can break them up into separate SlotServers and have them isolated but still communicate with each other quite nicely and effectively.

Disclosures and self-promotions dep't

If you are interested in seeing SlotServer in action and will be in Vegas at Interop next week (sorry, I am skipping the show myself), stop by booth # 10304 and see their demo, or check out the company's web site at www.omnicluster.com.

I've known some of the people behind the company for quite some time. The actual idea for a SlotServer was first demonstrated to me by Chet Heath when he was at IBM developing the MicroChannel about ten years ago. And before I got a chance to actually test the product this week, I saw a demo two years ago and was impressed enough to craft this op/ed piece for Network World.

IBM never commercialized the notion, which is one of the reasons Chet and others left Big Blue to start their own company. I wish them well, and think they have the makings of something rather unique.

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David Strom
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entire contents copyright 2001 by David Strom, Inc.
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