It's pretty subjective, but we tried moving our task-driven frontend load to dynamic backend instances. We found that, perhaps due to the nature of our workload, the dynamic backend pools never shrunk - e.g., if I configured 5 instances, 5 were always active. This had the effect of costing a lot more instance-hours of billing than simply using frontend instances, so we rolled back. Additionally, there would have been the extra overhead of manually monitoring to determine if 5 instances is the appropriate number to be processing our workload in a timely fashion (yes, I realize my conflicting statements here of wanting to be able to control my instance-hours while at the same time having some automation around the number of instances to serve the load).
For us to successfully use backends, I think we'd need more dials. E.g., I'd like to be able to tell the backend scheduler to not start a new instance until the incoming request queues have a certain level of pressure (e.g., # of tasks waiting, or estimated wait time in queue) and conversely, some way to tell the scheduler to ramp down instances when this pressure becomes too low. j -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
