This time it appears sites were better prepared for the traffic onslaught, but there were still problems, particularly with streaming video.
According to Gomez Incorporated, a company that monitors Web usage quality, there were both slowdowns and outages, including one that dramatically slowed Twitter's performance. The company analysed performance on seven news sites from multiple locations during Tuesday's event, with some of the biggest slowdowns coming to streaming video. Asia experienced a 40 per cent increase in what the company calls 'stalling issues', with the US experiencing an increase of around 5 per cent.
One of those news outlets that was serving up live streaming video was CNN, which according to internal data, topped out at 781,000 concurrent streams of the event. Between midnight EDT and 4pm, the site also pulled in 11 million unique users who turned 72 million pages.
Ustream, which provided live streaming in a partnership with CBS (CNET UK's parent company), says the event was the "largest ever" that had been hosted on the service, in part because it was a worldwide broadcast. The service had 4.6 million streams of the memorial going, made up from 1.6 million unique users. It also had more than 12,000 messages posted every minute to its built-in user chat rooms.
Besides slowdowns in streaming video, news sites also had lower availability, which means some users were unable to access them. Gomez recorded that number as low as 98.2 per cent, whereas the sites usually maintain uptime in excess of 99.65 per cent. Response times also took a hit. News sites experienced double, and nearly triple the load time to serve up pages.
In the case of Twitter, many users were unable to view or post messages to the service. At what was seemingly the peak of Twitter's load, Gomez benchmarked it as taking around 62 seconds for the site's home page to load, then allow users to log in -- a process that normally takes just a few seconds.
Larry Dignan, over at CNET UK's sister site ZDNet.com, points to data host Akamai's visualisation tool (pictured above), which shows real-time activity on its sites, which represent around 20 per cent of the Web's traffic. There's a noticeable bump around the time the memorial service begins.