By: Jon W
Running a large web site is quite interesting. Not only do you have a *lot* of customers to keep happy, but you also have a *lot* of hardware to keep happy. Racks and racks of servers go into making sure that IMVU is always available, 24 hours a day, 7 days a week, except for occasional brief outages.
One of the kinds of servers we use is known as “memcached,” which is a simple way of reducing the workload for database servers by caching the result of frequent database queries in memory. This has two benefits:
- It reduces load on the database servers (which are expensive) and moves it to machines that just have a lot of memory (which is cheap).
- It allows us to serve web pages faster. Each web page within imvu.com is the result of several database queries; if the result of all of those queries is already in memory somewhere, we can send the page back in less than a second, whereas it would take longer than that if we had to go to the database for each query.
That being said, it’s no surprise that we have a significant number of servers running memcached to improve the speed and performance of our site. It used to be that when your memcaches hit 50,000 requests per second, they would top out — but that was a couple of years ago. It also used to be that you would switch to (potentially lossy) UDP for memcached traffic, rather than staying on (potentially laggy) TCP. However, for better or for worse, we’ve stayed on TCP for our memcached traffic for now.