The good, the bad, and the leaky: jemalloc, bumpalo, and mimalloc in Meilisearch

This post details the investigation and resolution of memory leaks in Meilisearch, primarily focusing on the interaction between different memory allocators (jemalloc, mimalloc, bumpalo) and the LMDB dependency. It highlights a leak related to `bumpalo::Vec::into_bump_slice` and a more significant issue stemming from the non-cooperation of LMDB's system allocator with Meilisearch's custom global allocator (mimalloc). The solution involved unifying the allocator by using jemalloc and later mimalloc v3 with its override feature, leading to significant memory usage reduction and performance improvements.