Performance issue: gRPC publish, ack makes expensive AWS calls

[dmacthedestroyer]

When subscribing or publishing, the gRPC server will ensure that the topic and queues are properly configured. This was an intentional design decision to ease the burden of managing these resources by the developers.

A side effect is that every call to Publish() and Ack() is making these checks, which include some rate-limited calls to SNS and SQS. This causes slowness that's tolerable, but more importantly, will possibly cause a large system to behave sporadically.

The most straightforward solution is local caching of the persistent portions of AWS connections: Topic, Subscription, Queue Arns, etc.