At 17:44:53 the controller said 30 calls (tools, nodes, modules) were "kept in memory only: the bus is
not taking calls' records". No write had failed (no "could not be kept" line): a burst of about 200 read
calls in one second queued a begin and a finish each into a channel of 256 while the one writer put
them one by one, and the channel overflowed.
The queue now holds the latest state of each waiting call (a finish replaces its own waiting begin, as
only the last state is kept anyway), in first-queued order, bounded at 8192 calls; the writer takes the
whole queue at each wake. A burst now costs one write per call and drops nothing.
Quick fix: a larger channel. Thorough fix: coalesce by call, so the writes a burst asks are halved and
the bound is spent on calls, not states. Chose thorough; both are small.
Research 072 piece: §2's "read calls said" row: the calls bucket is the controller's own state on the
bus, kept from events (each call's change), never re-read.
jschoubben
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