Pretty much the question. We would like to update in-memory cache on the servers at once by issuing a “reload” request to only one of them. Perhaps this is possible with some Fly-specific header?
Clarification: the instances are in the same region, and all of them have to be hit with the request.
Hi,
Interesting. There is a fly-replay header that may be useful to you. You can replay a request in a region, app, or even on a particular instance. Check out this and scroll down:
… but I believe that only works for one request. I wonder if you could pass a comma-separated string of instance IDs as the value to replay the request in multiple instances 
If not … I guess you would need to loop over your instances. I wonder if you could make use of the private network to e.g get back all the instances in a region using a <region>.<app>.internal call, then issue the request to each. For more on that: