monero: check every five minutes again

The probes, the unit check and the public checks ran once a day with 26h
windows, justified as "a multi-week initial sync on a rotating disk". That
stopped being true: the node is synced, and a cold explorer page now renders
in 29s and a warm one in 0.2s - polling every 5 minutes is what keeps it warm.
A dead monerod could go unnoticed for a day.

Back to the standard 5m cadence and 11m heartbeat; the per-host
service_health override on monerod-box is gone.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ansible/roles/monero/defaults/main.yml

@@ -104,15 +104,17 @@ healthcheck_push_url: ""
 # is set: Gatus rejects an unauthenticated push with 401.
 healthcheck_push_token: ""
 
-# WHEN TO CHECK. Daily, at a fixed hour, rather than an OnUnitActiveSec
-# interval that drifts with every restart.
+# WHEN TO CHECK. Every 5 minutes, on the calendar rather than OnUnitActiveSec so
+# the cadence does not drift with every restart. (It was daily while the node
+# did its initial sync on a rotating disk; since 2026-10-03 the chain is on NVMe
+# and fully synced, and get_info answers in well under a second.)
 #
 # Prefixed because the generic `healthcheck` role owns the unprefixed
 # healthcheck_on_calendar; an unprefixed default here would shadow it for any
 # play that includes both.
 #
-# Paired with the 26h Gatus heartbeat in
+# Paired with the standard 11m Gatus heartbeat in
 # infra/403_service_probe_registration.yml. Change one and you must change the
 # other: the window has to stay above the interval or the check alerts on its
 # own jitter.
-monero_healthcheck_on_calendar: "*-*-* 05:00:00"
+monero_healthcheck_on_calendar: "*:0/5"

ansible/roles/monero/templates/healthcheck.timer.j2

@@ -8,17 +8,13 @@ Description=Monero Node Health Check Timer
 
 [Timer]
 OnBootSec=2min
-# ONCE A DAY, not every 5 minutes.
-#
-# A 5-minute poll of monerod buys nothing a daily one does not: the node is a
-# multi-week initial sync on a rotating disk, and every failing poll is another
-# Signal message. The cadence and the Gatus heartbeat window are ONE decision -
-# the window MUST exceed this interval, and it is set to 26h in
-# infra/403_service_probe_registration.yml. A 24h push under a 24h window races
-# itself and alerts on jitter alone.
+# Every 5 minutes (see monero_healthcheck_on_calendar). The cadence and the
+# Gatus heartbeat window are ONE decision - the window MUST exceed this
+# interval, and it is the standard 11m in
+# infra/403_service_probe_registration.yml.
 OnCalendar={{ monero_healthcheck_on_calendar }}
-# Spread against the other daily pushes leaving this box.
-RandomizedDelaySec=900
+# Small: a delay comparable to the interval would eat the heartbeat's slack.
+RandomizedDelaySec=30
 Persistent=true
 
 [Install]

ansible/roles/xmrblocks/defaults/main.yml

@@ -74,8 +74,9 @@ healthcheck_push_url: ""
 # is set: Gatus rejects an unauthenticated push with 401.
 healthcheck_push_token: ""
 
-# WHEN TO CHECK. Daily, 30 minutes after monerod's own check so the two do not
-# contend for the same cold LMDB pages. See roles/monero/defaults for why the
-# name is prefixed and why this is paired with the 26h heartbeat in
-# infra/403_service_probe_registration.yml.
-xmrblocks_healthcheck_on_calendar: "*-*-* 05:30:00"
+# WHEN TO CHECK. Every 5 minutes, offset 2 minutes from monerod's own check so
+# the two do not land together. On NVMe a cold page render measured 29s and a
+# warm one 0.2s (2026-10-17); a 5-minute poll is what keeps it warm. See
+# roles/monero/defaults for why the name is prefixed and why this is paired
+# with the 11m heartbeat in infra/403_service_probe_registration.yml.
+xmrblocks_healthcheck_on_calendar: "*:2/5"

ansible/roles/xmrblocks/templates/healthcheck.timer.j2

@@ -7,14 +7,13 @@ Description=Onion Monero Blockchain Explorer Health Check Timer
 
 [Timer]
 OnBootSec=2min
-# ONCE A DAY, not every 5 minutes. See the note in roles/monero's timer: the
-# explorer follows the node it reads from, and this check costs a full page
-# render out of the LMDB (a cold one measured 68 seconds), so polling it hard
-# is not free either. The Gatus heartbeat window is 26h, set in
+# Every 5 minutes (see xmrblocks_healthcheck_on_calendar). The check renders a
+# full page out of the LMDB: 29s cold, 0.2s warm on NVMe - frequent polling is
+# what keeps it warm. The Gatus heartbeat window is the standard 11m, set in
 # infra/403_service_probe_registration.yml, and MUST stay above this interval.
 OnCalendar={{ xmrblocks_healthcheck_on_calendar }}
-# Spread against the other daily pushes leaving this box.
-RandomizedDelaySec=900
+# Small: a delay comparable to the interval would eat the heartbeat's slack.
+RandomizedDelaySec=30
 Persistent=true
 
 [Install]