Constant polkadot_overseer::KNOWN_LEAVES_CACHE_SIZE

pub const KNOWN_LEAVES_CACHE_SIZE: usize = 2 * 24 * 3600 / 6; // 0x0000_0000_0000_7080usize

Store 2 days worth of blocks, not accounting for forks, in the LRU cache. Assumes a 6-second block time.