Some data on how long it is between fetches of my Atom feed
Recently I became interested in a relatively simple question: on average, how much time passes between two fetches of the Atom feed for Wandering Thoughts? Today I want to give some preliminary answers to that. To make life simple, I'm looking only at the blog's main feed and I'm taking 24 hours of data over Friday (local time). Excluding feed fetch attempts that are blocked for some reason, I get the following numbers:
- the straight average is one fetch every 12.9 seconds (with a standard deviance of 13.7).
- the median is one fetch every 9 seconds.
- the longest gap between two feed requests was 130 seconds.
- 90% of the inter-request gaps were 31 seconds or less, 75%
were 18 seconds or less, and 25% were 3 seconds or less.
- 6% of the feed fetch requests came at the same time (to the second) as another request; the peak number of fetches in one second is four, which happened several times.
- 7.5% came one second after the previous request (and this is the mode, the most common gap), 6% two seconds, 6% three seconds, and 5.5% four seconds. I'm going to stop there.
Of course averages are misleading; a thorough workup here would involve gnuplot and peering at charts (and also more than just 24 hours of data).
This is an interesting question partly because every so often people accidentally publish a blog entry and then want to retract it. Retraction is difficult in the face of syndication feeds; once an entry has started to appear in people's syndication feed fetches, you can no longer just remove it. My numbers suggest strongly that even moderately popular blogs have very little time before this starts happening.