There are a few performance-sensitive places in our codebase where we still use the outdated MurmurHash3 algorithm, where we could replace it with the more efficient CityHash algorithm (i.e.from absl::hash). Some uses of MurmurHash3 must be preserved, as the hash value is stored persistently or shared across the network and must be consistent between nodes. But for some uses, the value is local and transient, and can be replaced with any valid hash function.

We should determine which uses are safe to replace, and evaluate the performance impact of these replacements.