Crate tower_fallback

A service combinator that sends requests to a first service, then retries processing on a second fallback service if the first service errors.

Fallback designs have a number of downsides but may be useful in some cases. For instance, when using batch verification, the Fallback wrapper can be used to fall back to individual verification of each item when a batch fails to verify.

TODO: compare with similar code in linkerd.

Modules

• future
  Future types for the Fallback middleware.
• service 🔒

Structs

• Fallback
  Provides fallback processing on a second service if the first service returned an error.

Type Aliases

• BoxedError
  A boxed type-erased std::error::Error that can be sent between threads.