Cloudflare's replacement for KT that jgrahamc mentioned - Quicksilver - uses LMDB for storage.
I don't have numbers, but it performs great for our needs. It's heavier on the disk though because of fsync, however unlike KT we never get database corruption on disk.
I don't have numbers, but it performs great for our needs. It's heavier on the disk though because of fsync, however unlike KT we never get database corruption on disk.