The materializer's stream puller: one loop, from snapshot to live.

Pulls this materializer's shard stream from a Demux ShardServer — chunks for history, buffer for recent data, seamlessly — instead of drinking the whole WAL from the log. The materializer's only contact with a log is discovery: Log.get_shard_server/2, once per session (and again on failover).

Discovery

The replica set arrives in the unlock seed: [{log_id, log_ref}], resolved once by the director through the same ShardRouter walk the commit proxies route with (ShardRouter.log_ids_for_tag/3) — the puller never re-derives placement. Any replica works: every replica sees the same slices and the same cuts, so their chunks are byte-identical and their buffers hold the same suffix. Failover walks the replica set with the same circuit-breaker pattern the old log puller used.

Currency

An empty pull reply that carries a high-water — "nothing for you, but you are current through v" — is rematerialized as a heartbeat: an empty transaction at v fed through the normal apply path. Version advancement, read wake-ups, and window math all ride existing code, unchanged.

Backpressure

Batches are handed to the owner through a synchronous ingest function whose reply the owner withholds while its intake queue is over high-water. The puller cannot outrun the applier because the applier holds the reply.