Periodically log/export information on sites' states

[Fra-nk]

• Machine Registry
• Site Stats
• Average machine runtime
• number of "failed" VMs [require machines to traverse states without skipping a single state. Skipping a state can then be easily identified as erroneous?]

[Fra-nk]

First goal: "Only" export the data and rely on other tools, for example Ganglia to do the logging/plotting.

The enhancement should also be extended to integration and requirement adapter to replace JSON/CSV logging.

Potential for further development: RRDtool would be a good option, if we want to store the information ourselves:

• The current export format either produces a lot of "waste" or requires a lot of manual reprocessing (reduce ~3000 values to a few values per day, (moving) averages, etc.)
• Is there need for detailed data (accuracy = seconds) for more than a few months ago?
• 1-2 year of data should be enough.
  If somebody needs 10 years of history, a simple cronjob can save the RRD.