Constant MAX_KEPT_RELEASE_BYTES 

const MAX_KEPT_RELEASE_BYTES: u64 = _; // 4_096u64

Largest segment of release records that recovery keeps from the bytes it read for a footer. It keeps them before it knows which objects are on the chain, so the bound caps what objects off the chain hold until recovery ends; a larger segment is read again if its object is on the chain. A release seals its record at once, so a segment usually holds the records of one or a few regions, 16 bytes each.