As per a request by sporty we will start adding a new attribute to the XML tickers that will show what PerlMonks considers to be the minimum acceptable time between polling that ticker. This infomation will be available through the 'min_poll_seconds' attribute of the INFO element that is supplied with the ticker. (At the time of writing this post only the Private Message XML Ticker provides this attribute, but as soon as we can we will add it to the rest.)

Any client utilizing the XML feeds is expected to comply with this value if it is provided. So essentially the first fetch from a ticker will tell you how often you can fetch from it. If no such value is provided then please use as conservative a delay as possible. Anything more frequent than twice a minute is almost certainly too often. Remember we all have to share the site, so if in doubt err on the side of lower load.

(Update)Note: Its important that clients are written to check this attribute every time they get a response, especially if they are long running. We want to be able to tweak these parameters for all clients from PM, so dont just fetch once and then use that until process termination. You should code your client so that if the value changes so does your polling frequency.

Thanks for you compliance, and patience, but overall the changes being made to the XML tickers should benefit us all through lower DB loads, and extra features.