Planet feed polling frequency

From reading my web stats yesterday it seems that one Planet has polled by blog feed 1693 times over the first 14.25 days of this month. This is about 5 polls per hour. Another Planet has polled my blog 994 times for an average of about 3 hits per hour.

How frequently does it make sense to poll blogs? Speaking for myself I think that waiting an extra 10 minutes to see my latest blog post isn’t going to hurt anyone, and encouraging Planet readers to reload the page so frequently probably isn’t doing them a favour either.

For my own personal Planet installation (which mainly aggregates other Linux Planets for my own personal use) I have it poll the feeds every four hours. For a Planet installation designed for general readership it would make sense to have it poll more frequently. Maybe once every hour or once every half-hour.

When I initially set up my own planet installation I aggregated the entire feed list of Planet Debian and Planet Linux Australia and it generally took between 10 and 30 minutes to poll all the feeds with 20 minutes being common (Planet does not support parallel downloads). So for a moderate sized Planet with frequent polling you might have one poll end after the next cron job for a poll has begun.

It’s a pity that Planet doesn’t support pings. Will the next version do so? I would rather have my blog ping the Planets that I know of that aggregate my content and save thousands of needless polls while also giving a faster update.

Finally if you need a fast response for a dialogue then probably blogs and Planets are not the communication mechanism to use, a mailing list would probably be more appropriate.

3 comments to Planet feed polling frequency

  • Thom May

    uh, why does it matter? If you’re worried about bandwidth, provide etags and last-modified; otherwise, who cares?

  • Ted

    I only very recently added an RSS to my rarely-posted-to blog, but already I’ve noticed a client called “ROME” hitting the feed every 7 minutes. Despite my feed having a ttl of 1440 – ie. one day. Fortunately it understands caching and just gets an HTTP 304 Not Modified response every time.

  • Previous RSS etiquette notes I have seen recommend a minimum poll interval of 15 minutes, and this is followed by all desktop RSS readers I have used.