Election Night is one of the great scheduled scalability challenges. The extraordinary interest in the U.S. Presidential election is likely to translate into enormous web traffic tonight, and news sites and political blogs have had months to prepare. This is the political equivalent of the Super Bowl, and sites are scaling up to meet the challenge. Several hosting companies report increased sales of dedicated servers, and election traffic will likely be a boon to content delivery networks (CDNs).
For some sites, preparing their infrastructure has already been a lengthy process. "I've done a lot of stuff since January to get the site ready for Election Day, since we also had primary election traffic to worry about," said Jeremy Bingham, who manages the back end for Daily Kos, the hugely popular political blog. "Our images are on a CDN, but the rest of the site doesn't lend itself to caching on a CDN because of its dynamic nature."
Hardware is part of the solution, Bingham says. "To handle the traffic better, we moved to a cluster of six quad core Xeons with 8GB RAM for webheads that all boot off a central NFS (Network File System) root, with the capability of adding more webheads as needed," he said. Daily Kos also added two 16GB eight-core Xeons and a 6x73GB RAID-10 array for database files running a MySQL master/slave setup.
Hosting companies have reported increased demand for new hardware in recent weeks. "A few customers have ordered additional servers in order to support the expected increase in traffic over the last few weeks and for the next couple of days," said George Karidis, CTO of SoftLayer, who said the hosting company has seen an even larger jump in orders for add-on services to help them scale. "In the past few days we have noticed an up-tick in the number of people buying 'availability' services like CDNLayer (a content delivery service) and load balancing. Many of these are related to 'spike' oriented traffic like the election."
Karidis would not discuss individual customers, but the popular political news aggregator Memeorandum is hosted at SoftLayer.
Election night will provide a test for Twitter, the microblogging service which was once known for its downtime but has vastly improved its reliability in recent months. Twitter recently launched an Election 2008 channel which filters out political tweets and is receiving hundreds of updates each minute.
Several other popular new election sites likely to see unprecedented traffic include Electoral Vote projection services FiveThirtyEight and 270toWin, which are both hosted on platforms known primarily for their affordability. FiveThirtyEight is hosted on Google's Blogger platform, while 270toWin hosts with 1&1 Internet. Another popular new election-tracking site, Pollster, is hosted with Cogent Communications, which is once again reachable from the entire web after ending its peering dispute with Sprint.
Many database-driven sites facing scalability challenges have looked to the distributed caching system memcached, which helps speed dynamic web applications. Bingham says memcached has played an important role in scaling the Daily Kos site. "I greatly expanded memcached usage with 1GB instances memcached running on each webhead, which they all share," said Bingham. "The backend also places fully rendered pages into memcached, which a hacked up lighttpd running as the front end proxy then serves these pages from memcached directly to anonymous users. This has helped the sites performance immensely, since not only does it spread the work of rendering these pages around to the all of the webheads, but it greatly reduces the amount of work the backend has to do."
It will be a busy night for content delivery services, which cache customer content around the globe, moving files closer to the user to improve web site performance and reduce network traffic. The official campaign sites are each using CDN services, with BarackObama.com being supported by Panther Express, while JohnMcCain.com is using EdgeCast.
Limelight Networks (LLNW), which hosts many video sites, says Election Night will be busines as usual. "Limelight built its global network to support extremely large Internet audiences and to handle the 'flash crowds' that typically occur on news sites during elections," said Limelight spokesman Paul Alfieri, who said Limelight recently expanded the capacity of its network to over 2 Terabits per second.
"Usually, when a customer is expecting a large event, we’ll have a planning meeting between the engineering teams to make sure that we are coordinated," said Alfieri. "But more than that, there isn’t anything different that we do in these instances. The scalability of our platform is what our customer relationships are based on, and events like Election Day are when our customers count on us to deliver."
The web's busiest sites are bracing for enormous traffic. Yahoo had 80 million page views on Election Day in 2004 and 142 million the following day, according to the New York Times. when Sen. John Kerry conceded. "We expect to do twice or perhaps three times s much traffic in 2008," Neeraj Khemlani, the vice president for programming and development at Yahoo, told the Times.
Where can you track Internet traffic levels tonight? The best source may be the Visualizing the Internet application from Akamai (AKAM), which includes real-time graphics depicting traffic to news sites supported by Akamai's CDN service. The all-time peak is 7.28 million visitors per minute during the 2006 World Cup.