Brainstorm on whether Glance needs to protect itself from inadvertent DDoS'ing by throttling eager clients, and also whether fairness should be enforced by rationing resource usage. The obvious approach would be to model this on nova rate-limiting, possibly leveraging the distributed mechanism provided by Turnstile in the case where the Glance API service is horizontally scaled. However Glance may have additional requirements, for example weighting GET calls on the size of the image returned (which can vary by several orders of magnitude). Also the nova quota/quota-classes API extensions could be useful to re-use, though again Glance may have some special requirements, for example weighting resource usage depending on the backend store in use (limited local filesystem space may for example attract a higher weighting than effectively infinite S3 storage). (Session lead is Eoghan Glynn)
Tuesday April 17, 2012 5:00pm - 5:25pm PDT
Seacliff C
