[atlas] Warnings about running out of credits and runaway measurements

Dear Atlas users,

Today we're going to enable two features that have been forecasted in the
January 2013 Atlas update
(https://labs.ripe.net/Members/becha/ripe-atlas-january-2013-achievements)

Both of these features are intended to prevent runaway measurements which
consume system resources, and to limit the resources used by users who don't
contribute (any more) to the system; thus they both contribute to the
stability and scalability of RIPE Atlas. They are both controlled by the
credit system.

The first feature is about sending warning emails if someone is about to run
out of credits. That is, if the current credit consumption rate (with a two
day lookback period) seems to use up all credits of a particular user within
the next week or so, then we'll send an email about this. This allows the
user to organise some extra credits, or stop some less important
measurements in due time.

The second feature stops measurements if someone actually runs out of
credits. For now we'll use a *warning only* mode -- that is, the process
will not actually stop measurements, it will only send emails. After a
couple of weeks we'll change this to actually stop (some of the)
measurements as well as notify the user.


Our tests show that at the moment there are about a dozen people who would
see effects of these processes.


Both of these are necessary steps towards removing the existing limits
imposed by the system (such as maximum amount of probes that can be used).

Please let us know if you have questions or concerns, either on this mailing
list, or (privately) by sending a mail to atlas at ripe.net


Best regards,
Robert Kisteleki
RIPE Atlas team