Prepare, test and review
Online shoe retailer Zappos conducts load testing early in the fall to ensure its site stays up and highly available during the holiday season, says Kris Ongbongan, senior manager, technical operations and systems engineering. Every year they follow the same procedure, he says: estimate load.
"We have our finance and planning departments give us sales predictions and we take a multiple of that to see what traffic we can absorb and test to that," typically beginning in September, Ongbongan says. That gives them enough time to make changes and add any necessary infrastructure.
Retailers should go through their transaction volume testing and validation in the September/October timeframe and then code lock their systems until about January 15th, suggests Michael Ebert, a partner in IT Advisory Services at KPMG. During that period, "retailers typically freeze their systems ... and don't do updates unless absolutely necessary to avoid performance issues,'' he says.
Another practice the very large Internet retailers tend to employ is having distributed networks in order to route traffic to make sure transactions are balanced around the U.S., Ebert says. That way, if one site gets too busy the customer will automatically be routed to another. "So make sure you have multiple points of your Internet presence around the U.S." A data center "may be slow to respond, but at least I'm up and running,'' he adds. "There's always a percentage of business you never regain if someone leaves the site."
Another metric that retailers need to be concerned with is latency, or the response time for how long it takes a page to load and for the payment transaction to be completed. "I expect we'll see some latency concerns" or other problems during the check-out step during this holiday season, predicts Greg Girard, program director, IDC Retail Insights. That's because there are throughput bottleneck issues at the gateway to the credit card processing network, he says.
"The micro-economic problem is that it costs money to maintain capacity that you utilize only at the peak time, which is only very infrequently during the year. It's an economical tradeoff you have to make."
Over-provisioning via cloud
For a lot of smaller online retailers, it's hard to justify the return on investment for increasing the capacity they need to handle 12 hours of peak usage on one day of the year, says Girard. "That's where cloud comes into play, and we're seeing some retailers adopt cloud strategies. That's really going to progress going forward." Retailers will be able to get additional peak capacity at an incremental cost by moving to the cloud, he says.
Zappos' Ongbongan says they handle all network functions internally and do not use cloud providers. "We have instrumentation around every transaction point on the website, from search pages to product detail pages to checkout," he says, "so we can look at each individually to see if there's any slowness or problems in any of those areas."
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