EBay Infrastructure

A series of service disruptions in 1999 caused real problems for eBay's business. Over the course of three days, overloaded servers intermittently shut down, meaning users couldn't check auctions, place bids or complete transactions during that period. Buyers, sellers and eBay were very unhappy, and a complete restructuring of eBay's technological architecture followed.

In 1999, eBay was one massive database server and a few separate systems running the search function. In 2005, eBay is about 200 database servers and20 search servers.

The architecture is a type of grid computing that allows for both error correction and growth. With the exception of the search function, everything about eBay can actually run on approximately 50 servers -- Web servers, application servers and data-storage systems. Each server has between six and 12 microprocessors. These 50 or so servers run separately, but they talk to each other, so everybody knows if there is a problem somewhere. EBay can simply add servers to the grid as the need arises.

While the majority of the site can run on 50 servers, eBay has four times that. The 200 servers are housed in sets of 50 in four locations, all in the United States. When you're using eBay, you may be talking to any one of those locations at any time -- they all store the same data. If one of the systems crashes, there are three others to pick up the slack.

When you're on the eBay Web site and you click on a listing for a Persian rug, your computer talks to Web servers, which talk to application servers, which pull data from storage servers so you can find out what the latest bid price is and how much time is left in the auction. eBay has local partners in many countries who deliver eBay's static data to cut down on download time, and there are monitoring systems in 45 cities around the world that constantly scan for problems in the network.

This infrastructure lets millions of people search for, buy and sell items simultaneously. On the user end, it all works seamlessly. Let's try it out.

Using eBay: Browsing for Items

The best way to learn how to use eBay is to dive right in. What do you feel like looking for today? Asurround-sound system? A mink stole? HowStuffWorks could use a Homer Simpson Pez dispenser. Let's look for one.

There are two ways to go about finding a Homer Simpson Pez dispenser. We can browse, or we can search. Let's start by browsing -- it's the slower, more round-about method, but it's a good way to get a feel for eBay's category system. The most popular categories are listed right on the eBay homepage, on the left side.

Pez dispensers are typically considered collector items, so the Collectibles category is a good place to start browsing. If we click on the Collectibles link on the homepage, we end up at a page listing all of the Collectibles subcategories.

At the very bottom of the page, you can see that there's actually a subcategory called Pez, Keychains, Promo Glasses, and within that subcategory is another subcategory called Pez.

That seems like a good fit. Clicking on "Pez" brings us to an auction-level page:

On this page, you can see that:

· There are 3,355 listings in the Pez category.

· The listings are currently sorted by time, with the newest auctions first.

· We can search within Pez listings.

Since we're looking specifically for a Homer Simpson Pez dispenser, "Homer Simpson" is a good term to use to narrow the results. If we enter "Homer Simpson" in the search box directly above the listing, it's only going to search the Pez subcategory, not all of eBay (although you can search all of eBay using a dropdown menu in the category field). Here's what comes up:

Thirteen items isn't bad, but we might be able to find more. When you enter a search term and there are fewer results than you'd like, the first thing to do is go back up to the search field and check the box for "Search title anddescription." The first search we did checked only the auction titles for the term "Homer Simpson." Searching only titles is a good way to narrow your results if you know exactly what you're looking for and what most people call it -- for example, if you're looking for a GPS receiver, it's a pretty safe bet that anyone selling one would put "GPS" in the title. On the other hand, someone selling a Homer Simpson Pez dispenser might not put "Homer Simpson" in the title -- she might put "Simpsons" or only "Homer." So now we're going to search entire auction descriptions, which typically returns more results:

We now have 23 listings to look through. But there is a much faster way to get to the place we've ended up at. If you're just looking for a bargain on some type of collectible, browsing is the way to go; but if you're looking for something specific, the eBay search function is the quickest way to it.

Using eBay: Searching for Items

At the top of the eBay homepage, there's a search box where we can enter what we're looking for.

Here's what comes up in our simple keyword search:

Date: 2015-02-03; view: 828