How we saved 100 terabytes of memory by optimizing 1.1.1.1’s DNS cache

The post details five specific memory optimization techniques applied to the 1.1.1.1 DNS cache: 1. Replacing `Vec<T>` and `String` with `Box<[T]>` and `Box<str>` to eliminate capacity fields and excess heap allocation. 2. Consolidating answer, authority, and additional sections into a single list with offsets, reducing pointer and length overhead. 3. Inferring record owners when identical to the queried domain to avoid redundant storage. 4. Boxing larger enum variants for `RecordData` to reduce wasted space from padding. 5. Packing boolean fields into a bitflag to reduce surrounding padding. The post also describes the benchmarking methodology used to measure memory usage, insert throughput, and lookup latency.