pub const MAX_COALESCING_KEYS: usize = 256;Expand description
Upper bound on concurrently held coalescing LEADER slots (DW-038). The map bounds memory (each slot is a key string + a watch channel) and the stampede-collapse itself: beyond this many DISTINCT in-flight cache keys, new misses never join — they fetch independently (fail open, uncounted by coalescing metrics). Slots are not evicted early (an in-flight leader cannot be preempted — its followers are parked on it); the map drains as leaders complete, which IS the eviction policy: hold-while-in-flight, remove-at-completion, refuse-at-capacity. A same-process burst with more than this many distinct keys was never going to collapse anyway — the keys are distinct.