`_spawn_gateway_restart` already reuses an in-flight `hermes gateway
restart` child so a double-clicked button cannot start two racing
restarts. That guard evaporates exactly when it is needed most: the
child exits as soon as it has handed the restart to the supervisor (or
to the running gateway), long before the gateway is actually back, so a
stale cached dashboard frontend re-firing its own restart every few
seconds cleared the guard on every attempt and started a fresh restart
each time.
#89034 measured the result on an s6-supervised container: 77
`gateway-restart started` entries, 17 of them inside one minute. Each
one SIGHUPs a gateway that is still coming up, and killing it
mid-FTS5-write corrupted `state.db` ("database disk image is
malformed", 203x in agent.log) until the operator recreated the file by
hand.
Requests for the same profile within GATEWAY_RESTART_COOLDOWN_SECONDS of
the last spawn are now coalesced onto that spawn and logged, so a storm
produces one restart instead of one per request. The window is fixed
rather than health-gated on purpose: a gateway that never comes back
would leave a health-gated restart action permanently inert, which is a
worse failure than the flood it prevents. The cooldown state is kept
outside `_ACTION_PROCS` because completed action children are reaped out
of that table, and a guard that disappears when the child exits is the
bug being fixed.
Only the *frontend-flood* half of #89034 is addressed here. The s6
`finish` death-cap the report also asks for is a separate change to
`hermes_cli/service_manager.py` with a much larger blast radius, and is
left for a maintainer decision.
Jack Lau
49cc3708e5