I have an application deployed across three regions (IAD, MIA, and LAX) on Fly.io. In addition, I have set up an Upstash Redis cluster with the primary region in IAD and read replicas in LAX and MIA.
Recently, I’ve been experiencing continuous crashes of the application in the IAD region. The error message states, “failed to connect to redis dial tcp: lookup .upstash.io on [fdaa::3]:53: no such host.”
However, I can use
fly redis connect to access the Redis cluster, which seems to be healthy. Additionally, the application instances in MIA and LAX have no issues connecting to the Redis cluster.
I am seeking help in identifying the cause of this issue and any potential solutions. Any ideas or suggestions are greatly appreciated.