Fixed odd issue with the cli not finding the socket properly

This gets rid of the alert on unknown -> up, will still alert unknown -> down by design.

CHANGELOG.md

@@ -4,6 +4,57 @@ All notable changes to this project are documented here. The format
 follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and
 this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v0.1.1] — 2026-05-15
+
+### Changed
+
+- **`install.sh` now repairs data-dir permissions on every run.**
+  Re-running the installer reasserts the canonical ownership
+  (`quptime:quptime`) and modes across `/etc/quptime/` — `0750` on
+  the dir, `0700` on `keys/`, `0600` on `node.yaml`, `cluster.yaml`,
+  `trust.yaml`, and `keys/private.pem`, `0644` on `keys/public.pem`
+  and `keys/cert.pem`. Makes the installer the one-step recovery
+  path when something has tampered with modes (e.g. a stray
+  `chmod -R`, a backup restore, or an accidental `sudo qu init`
+  that left files owned by root). Unknown files in the dir are left
+  alone.
+
+### Fixed
+
+- **CLI socket lookup as the daemon user.** `sudo -u quptime qu …`
+  no longer fails with `dial daemon socket /tmp/quptime-quptime/…:
+  no such file or directory` while the system daemon is running.
+  `config.SocketPath()` now probes the canonical systemd location
+  (`/run/quptime/quptime.sock`, then `/var/run/quptime/quptime.sock`)
+  regardless of euid before falling back to per-user paths, so the
+  CLI reaches the daemon's socket even when `sudo` has stripped
+  `RUNTIME_DIRECTORY` and `XDG_RUNTIME_DIR` from the environment.
+
+## [v0.1.0] — 2026-05-15
+
+### Changed
+
+- **Master election cooldown (2 min).** A returning peer with a
+  lower NodeID no longer reclaims master the instant it reappears.
+  It must stay continuously live for `DefaultMasterCooldown`
+  (2 minutes) before displacing the incumbent. Bootstrap and
+  quorum-regained-from-empty still elect immediately; the cooldown
+  only protects an active incumbent. Fixes #3: a self-monitoring
+  master (TCP check on its own `:9901`) would otherwise flap the
+  role in lock-step with its own restart.
+
+### Fixed
+
+- #1 Previously up services are alerted as going back up if the master goes down.
+  Ignore `unknown` -> `up` transitions during master election; still
+  alert on `unknown` -> `down` by design.
+
+## [v0.0.2] — 2026-05-15
+
+### Fixed
+
+- Text template field in the TUI did not support newlines, causing multi-line templates to render as a single line and losing formatting. This has been fixed by changing the field into a textarea and escaping the `enter` key to insert newlines.
+
 ## [v0.0.1] — 2026-05-15
 
 Initial public release.
@@ -87,3 +138,5 @@ Initial public release.
   Planned for a future release.
 
 [v0.0.1]: https://git.cer.sh/axodouble/quptime/releases/tag/v0.0.1
+[v0.1.0]: https://git.cer.sh/axodouble/quptime/releases/tag/v0.1.0
+[v0.1.1]: https://git.cer.sh/axodouble/quptime/releases/tag/v0.1.1

README.md

@@ -94,7 +94,11 @@ the hysteresis that absorbs network blips.
 
 Master election is deterministic: among the live members of the quorum,
 the node with the lexicographically smallest NodeID wins. No
-negotiation, no split-brain window.
+negotiation, no split-brain window. A 2-minute **master cooldown**
+keeps the current master in place until a returning lower-NodeID peer
+has been continuously live for the full window, so a self-monitoring
+master that briefly drops doesn't flap the role back the instant it
+reappears.
 
 `cluster.yaml` is the single replicated source of truth (peers, checks,
 alerts). Mutations from the CLI route through the master, which bumps a

docs/architecture.md

@@ -118,6 +118,35 @@ The `term` integer in `qu status` is bumped every time the elected
 master changes (including transitions to and from "no master"). Use it
 to spot flappy clusters.
 
+### Master cooldown
+
+The bare "lowest-live-NodeID wins" rule has one unpleasant edge: if the
+primary master is also being monitored by `qu` itself (a TCP check on
+its own `:9901`, say), a brief restart causes a master flap *and* a
+state flap in lock-step. The new master sees the old master come back
+on the next tick and immediately hands the role back, taking the
+just-recovering node from `unknown` to `up` with no quiet period.
+
+To absorb that, the quorum manager applies a **master cooldown**
+(`DefaultMasterCooldown`, 2 minutes) before a peer with a lower NodeID
+may displace the incumbent. The rules:
+
+- The cooldown timer starts on the **first heartbeat after a
+  dead-after gap** — i.e. when a peer re-enters the live set after
+  having aged out. Continuous heartbeats never restart it.
+- A flap during the cooldown resets the timer; the returning peer
+  must clear a full fresh window before taking over.
+- The cooldown applies **only when an incumbent master exists**.
+  Bootstrap and quorum-regained-from-empty elect the lowest-NodeID
+  live peer immediately, because there is no role to protect.
+- If the incumbent drops out of the live set, the cooldown is
+  irrelevant — any live peer may take over without waiting.
+
+The constant lives in `internal/quorum/manager.go`. Lower it for
+faster fail-back at the cost of monitoring-self flap risk; raise it
+to give a recovering master longer to settle before reclaiming the
+role.
+
 ## Catch-up when a node reconnects
 
 This is the scenario most people ask about: node C is offline, the

docs/installation.md

@@ -70,6 +70,15 @@ What it does:
    `/etc/systemd/system/quptime.service` (hardened — matches the unit
    in [systemd.md](deployment/systemd.md)). Enables but does not start
    the service, so you can configure identity before first boot.
+5. Repairs ownership and modes under `/etc/quptime/` to the canonical
+   layout (`0750` on the dir, `0700` on `keys/`, `0600` on
+   `node.yaml` / `cluster.yaml` / `trust.yaml` / `keys/private.pem`,
+   `0644` on `keys/public.pem` / `keys/cert.pem`). This makes the
+   installer idempotent for permission damage — if something
+   tightened or loosened modes (a stray `chmod -R`, a misguided
+   backup restore, an accidental `sudo qu init`), re-running
+   `install.sh` puts everything back without touching the contents
+   of those files.
 
 ## Build from source
 

docs/operations.md

@@ -183,6 +183,7 @@ Options:
 | `quorum`       | `true`         | `false` — no mutations, no alerts.                        |
 | `master`       | a NodeID       | `(none — ...)` — quorum lost or election in flight.       |
 | `term`         | slow growth    | rapid growth → master flapping, network unstable.         |
+| `master` after a restart of the primary | unchanged for ~2 min, then bumps back | bumps back immediately → cooldown disabled or misconfigured. |
 | `config ver`   | identical across nodes | divergence → a node is stuck pulling.             |
 
 A simple cron sentinel on each node:

docs/troubleshooting.md

@@ -35,6 +35,25 @@ flapping. Causes:
 - Heartbeat timeouts (default 4s) are too tight for your inter-node
   link. Rebuild with a higher `DefaultDeadAfter` if you need it.
 
+## Primary master came back but the cluster hasn't switched to it
+
+**What it means.** Working as designed. After a returning peer with a
+lower NodeID rejoins, the quorum manager waits
+`DefaultMasterCooldown` (2 minutes) before letting it displace the
+incumbent. The window prevents a self-monitoring master from flapping
+the role in lock-step with its own restart.
+
+How to confirm:
+
+- `qu status` on every node shows the same (current) master and a
+  steady `term` — not flapping. The lower-NodeID peer is in the live
+  set but not yet master.
+- After ~2 minutes of continuous liveness, `term` bumps once and the
+  master switches to the lower-NodeID peer.
+
+If you need a different window, change `DefaultMasterCooldown` in
+`internal/quorum/manager.go` and rebuild.
+
 ## A check is stuck in `unknown`
 
 **What it means.** The aggregator has no fresh reports for that check.
@@ -153,7 +172,9 @@ still see this error, the most likely causes are:
 
 - The data directory is read-only or owned by a different user — the
   bootstrap can't write `node.yaml`. Fix permissions on
-  `$QUPTIME_DIR`.
+  `$QUPTIME_DIR`. The fastest fix on a standard install is just to
+  re-run `install.sh` — it reasserts the canonical ownership and
+  modes on the whole tree without touching your config.
 - Something else removed `node.yaml` mid-run (a config-management
   tool, a misconfigured volume). Re-run `qu serve` and it will
   rebuild from env, or run `qu init` manually with the flags you
@@ -178,7 +199,9 @@ load private key: ...
 ```
 
 Permissions on `keys/private.pem` are wrong — should be 0600 and owned
-by the daemon user. Fix and restart.
+by the daemon user. Fix and restart. Re-running `install.sh` on a
+standard install is the easiest path: it repairs ownership and modes
+on the entire data dir.
 
 ## Probes look much slower than expected
 

install.sh

@@ -175,6 +175,63 @@ fi
 
 install -d -o "$SERVICE_USER" -g "$SERVICE_GROUP" -m 0750 "$DATA_DIR"
 
+# Repair ownership and permissions on the data dir's contents. Catches:
+#   - re-running the installer over a previous install where the
+#     service user/group changed.
+#   - the operator ran `qu init` or `qu serve` as root once (easy
+#     mistake: `sudo qu init` is shorter than the documented
+#     `sudo -u quptime qu init`). When the daemon runs as root its
+#     DataDir() resolves to /etc/quptime, so any files it writes land
+#     owned by root:root — the systemd service then fails with
+#     `open node.yaml: permission denied`.
+#   - someone or something (a stray `chmod -R`, a misguided backup
+#     restore) tightened or loosened modes. Re-running the installer
+#     should be enough to get back to a working baseline.
+# The canonical layout (mirrors the modes the daemon writes itself
+# in internal/config and internal/crypto):
+#   /etc/quptime/                 quptime:quptime  0750
+#   /etc/quptime/keys/            quptime:quptime  0700
+#   /etc/quptime/node.yaml        quptime:quptime  0600
+#   /etc/quptime/cluster.yaml     quptime:quptime  0600
+#   /etc/quptime/trust.yaml       quptime:quptime  0600
+#   /etc/quptime/keys/private.pem quptime:quptime  0600
+#   /etc/quptime/keys/public.pem  quptime:quptime  0644
+#   /etc/quptime/keys/cert.pem    quptime:quptime  0644
+# The runtime dir /var/run/quptime is owned by systemd via
+# RuntimeDirectory= and rebuilt at each service start, so we leave it
+# alone.
+repair_perms() {
+    # Always reset the top-level dir mode — `install -d` only sets it
+    # on creation, not on re-run.
+    chown "$SERVICE_USER:$SERVICE_GROUP" "$DATA_DIR"
+    chmod 0750 "$DATA_DIR"
+
+    # Reassert ownership across the whole tree in one pass.
+    if [ -n "$(ls -A "$DATA_DIR" 2>/dev/null)" ]; then
+        chown -R "$SERVICE_USER:$SERVICE_GROUP" "$DATA_DIR"
+    fi
+
+    # keys/ is a directory with its own tighter mode.
+    if [ -d "$DATA_DIR/keys" ]; then
+        chmod 0700 "$DATA_DIR/keys"
+    fi
+
+    # Each known file gets its canonical mode if it exists. We don't
+    # create anything that isn't already there — that's `qu init`'s
+    # job — and we don't touch unknown files an operator may have
+    # parked in the dir.
+    local f
+    for f in node.yaml cluster.yaml trust.yaml keys/private.pem; do
+        [ -f "$DATA_DIR/$f" ] && chmod 0600 "$DATA_DIR/$f"
+    done
+    for f in keys/public.pem keys/cert.pem; do
+        [ -f "$DATA_DIR/$f" ] && chmod 0644 "$DATA_DIR/$f"
+    done
+}
+
+repair_perms
+echo "> reasserted ownership ($SERVICE_USER:$SERVICE_GROUP) and modes under $DATA_DIR"
+
 echo "> writing $SERVICE_FILE"
 cat > "$SERVICE_FILE" <<'EOF'
 [Unit]
@@ -252,11 +309,18 @@ Next steps:
               # On follower nodes, also set the shared join secret:
               # Environment=QUPTIME_CLUSTER_SECRET=<paste from first node>
 
-       b) Or run \`qu init\` once explicitly:
+       b) Or run \`qu init\` once explicitly. IMPORTANT: run as the
+          ${SERVICE_USER} user, not root — otherwise node.yaml lands
+          owned by root and the service can't read it on start.
 
             sudo -u ${SERVICE_USER} QUPTIME_DIR=${DATA_DIR} \\
               qu init --advertise <this-host>:9901
 
+          If you already ran it as root and the service is failing
+          with "permission denied" on node.yaml, repair with:
+
+            sudo chown -R ${SERVICE_USER}:${SERVICE_GROUP} ${DATA_DIR}
+
   2. Start the service:
 
        sudo systemctl start ${SERVICE_NAME}

internal/alerts/discord.go

@@ -25,12 +25,20 @@ type discordPayload struct {
 }
 
 // sendDiscord posts msg.Subject + body to the configured webhook URL.
+// When the alert has a custom BodyTemplate, the rendered body is shipped
+// verbatim — the operator has opted out of the default subject header
+// and code-block wrapping in favour of their own formatting.
 func sendDiscord(a *config.Alert, msg Message) error {
 	if a.DiscordWebhook == "" {
 		return errors.New("discord webhook url not set")
 	}
 
-	content := msg.Subject + "\n```\n" + msg.Body + "\n```"
+	var content string
+	if a.BodyTemplate != "" {
+		content = msg.Body
+	} else {
+		content = msg.Subject + "\n```\n" + msg.Body + "\n```"
+	}
 	raw, err := json.Marshal(discordPayload{Content: content})
 	if err != nil {
 		return err

internal/alerts/dispatcher.go

@@ -27,7 +27,7 @@ func New(cluster *config.ClusterConfig, selfID string, logger *log.Logger) *Disp
 
 // OnTransition is wired as checks.TransitionFn.
 func (d *Dispatcher) OnTransition(check *config.Check, from, to checks.State, snap checks.Snapshot) {
-	if to == checks.StateUnknown {
+	if !shouldAlert(from, to) {
 		return
 	}
 	alerts := d.cluster.EffectiveAlertsFor(check)
@@ -77,6 +77,25 @@ func (d *Dispatcher) Test(alertID string) error {
 	return d.dispatchOne(alert, msg)
 }
 
+// shouldAlert decides whether a committed state transition warrants
+// firing the configured alert channels.
+//
+// A fresh master's aggregator starts every check at StateUnknown, so
+// the first successful evaluation always commits Unknown→Up. Without
+// filtering, every master failover (or daemon restart) would spam an
+// "is now UP" alert for every healthy check. We treat Unknown→Up as a
+// silent cold start; real recoveries (Down→Up) and any transition to
+// Down still alert.
+func shouldAlert(from, to checks.State) bool {
+	if to == checks.StateUnknown {
+		return false
+	}
+	if from == checks.StateUnknown && to == checks.StateUp {
+		return false
+	}
+	return true
+}
+
 func (d *Dispatcher) dispatchOne(a *config.Alert, msg Message) error {
 	switch a.Type {
 	case config.AlertSMTP:

internal/alerts/dispatcher_test.go

@@ -0,0 +1,30 @@
+package alerts
+
+import (
+	"testing"
+
+	"git.cer.sh/axodouble/quptime/internal/checks"
+)
+
+func TestShouldAlertFiltersColdStartUp(t *testing.T) {
+	cases := []struct {
+		name string
+		from checks.State
+		to   checks.State
+		want bool
+	}{
+		{"cold start to up (master failover / daemon restart)", checks.StateUnknown, checks.StateUp, false},
+		{"cold start to down still alerts", checks.StateUnknown, checks.StateDown, true},
+		{"real recovery alerts", checks.StateDown, checks.StateUp, true},
+		{"regression alerts", checks.StateUp, checks.StateDown, true},
+		{"stale (up to unknown) suppressed", checks.StateUp, checks.StateUnknown, false},
+		{"stale (down to unknown) suppressed", checks.StateDown, checks.StateUnknown, false},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			if got := shouldAlert(c.from, c.to); got != c.want {
+				t.Errorf("shouldAlert(%s→%s) = %v, want %v", c.from, c.to, got, c.want)
+			}
+		})
+	}
+}

internal/config/paths.go

@@ -16,6 +16,7 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
 // Default file names. Callers should always go through DataDir() so an
@@ -55,10 +56,47 @@ func DataDir() string {
 }
 
 // SocketPath returns the unix socket used for local CLI ↔ daemon control.
+//
+// Resolution order:
+//  1. $QUPTIME_SOCKET — explicit operator override.
+//  2. $RUNTIME_DIRECTORY — set by systemd when the unit declares
+//     RuntimeDirectory=quptime. This is the path the daemon uses
+//     when run under the packaged unit: /run/quptime/quptime.sock.
+//  3. The canonical system socket path — /run/quptime/quptime.sock —
+//     if it exists. This catches the CLI side regardless of who is
+//     invoking it: `sudo -u quptime qu status` strips RUNTIME_DIRECTORY
+//     and XDG_RUNTIME_DIR, so without this probe the CLI falls all
+//     the way through to /tmp/quptime-<user>/… and reports "no such
+//     file" even while the daemon is happily listening.
+//  4. /var/run/quptime/… when euid is 0 (CLI side, packaged installs
+//     on systems where /var/run isn't a symlink to /run).
+//  5. $XDG_RUNTIME_DIR/quptime/… for user-mode installs.
+//  6. /tmp/quptime-<user>/… as a last resort.
 func SocketPath() string {
 	if v := os.Getenv("QUPTIME_SOCKET"); v != "" {
 		return v
 	}
+	if v := os.Getenv("RUNTIME_DIRECTORY"); v != "" {
+		// systemd may pass multiple colon-separated entries when more
+		// than one RuntimeDirectory= is declared. Ours is single, but
+		// be defensive in case a future unit adds more.
+		if i := strings.IndexByte(v, ':'); i >= 0 {
+			v = v[:i]
+		}
+		return filepath.Join(v, SocketName)
+	}
+	// If a system-managed daemon is already listening, route there
+	// regardless of euid. Without this, `sudo -u quptime qu …` can't
+	// find the socket the daemon (also running as quptime) created
+	// via RuntimeDirectory=.
+	for _, p := range []string{
+		"/run/quptime/" + SocketName,
+		"/var/run/quptime/" + SocketName,
+	} {
+		if _, err := os.Stat(p); err == nil {
+			return p
+		}
+	}
 	if os.Geteuid() == 0 {
 		return "/var/run/quptime/" + SocketName
 	}

internal/quorum/manager.go

@@ -34,6 +34,12 @@ import (
 const (
 	DefaultHeartbeatInterval = 1 * time.Second
 	DefaultDeadAfter         = 4 * time.Second
+	// DefaultMasterCooldown is the grace period a returning peer must
+	// stay continuously live before it's allowed to displace the
+	// currently-elected master. Without it, a self-monitoring master
+	// that briefly drops would reclaim the role immediately on return
+	// and disrupt anything watching its TCP port.
+	DefaultMasterCooldown = 2 * time.Minute
 )
 
 // VersionObserver is invoked whenever a heartbeat exchange reveals
@@ -50,12 +56,14 @@ type Manager struct {
 
 	heartbeatInterval time.Duration
 	deadAfter         time.Duration
+	masterCooldown    time.Duration
 
-	mu       sync.RWMutex
-	term     uint64
-	masterID string
-	lastSeen map[string]time.Time // peerID -> last contact (sent or recv)
-	addrOf   map[string]string    // peerID -> advertise addr (last known)
+	mu        sync.RWMutex
+	term      uint64
+	masterID  string
+	lastSeen  map[string]time.Time // peerID -> last contact (sent or recv)
+	liveSince map[string]time.Time // peerID -> start of current liveness streak
+	addrOf    map[string]string    // peerID -> advertise addr (last known)
 
 	observer VersionObserver
 }
@@ -70,7 +78,9 @@ func New(selfID string, cluster *config.ClusterConfig, client *transport.Client)
 		client:            client,
 		heartbeatInterval: DefaultHeartbeatInterval,
 		deadAfter:         DefaultDeadAfter,
+		masterCooldown:    DefaultMasterCooldown,
 		lastSeen:          map[string]time.Time{},
+		liveSince:         map[string]time.Time{},
 		addrOf:            map[string]string{},
 	}
 }
@@ -242,7 +252,15 @@ func (m *Manager) tick(ctx context.Context) {
 
 func (m *Manager) markLive(id string) {
 	m.mu.Lock()
-	m.lastSeen[id] = time.Now()
+	now := time.Now()
+	prev, ok := m.lastSeen[id]
+	// A peer entering its first liveness streak — or returning after
+	// the dead-after window expired — resets liveSince. Subsequent
+	// heartbeats within the streak leave it untouched.
+	if !ok || now.Sub(prev) > m.deadAfter {
+		m.liveSince[id] = now
+	}
+	m.lastSeen[id] = now
 	m.mu.Unlock()
 }
 
@@ -276,7 +294,41 @@ func (m *Manager) recomputeMaster() {
 
 	var newMaster string
 	if len(live) >= quorum && len(live) > 0 {
-		newMaster = live[0] // lowest NodeID wins
+		// Without an incumbent the cluster is bootstrapping or
+		// has just regained quorum, so elect immediately — there's
+		// nothing to protect from a handoff.
+		if m.masterID == "" {
+			newMaster = live[0]
+		} else {
+			newMaster = m.masterID
+			now := time.Now()
+			incumbentLive := false
+			for _, id := range live {
+				if id == m.masterID {
+					incumbentLive = true
+					break
+				}
+			}
+			// If the incumbent is no longer live, any live peer
+			// may take over without waiting.
+			if !incumbentLive {
+				newMaster = live[0]
+			} else {
+				// Incumbent is live. A peer with a lower NodeID
+				// may only displace it after it has stayed
+				// continuously live for masterCooldown.
+				for _, id := range live {
+					if id >= m.masterID {
+						break // sorted ascending — nobody lower left
+					}
+					since, ok := m.liveSince[id]
+					if ok && now.Sub(since) >= m.masterCooldown {
+						newMaster = id
+						break
+					}
+				}
+			}
+		}
 	}
 	if newMaster != m.masterID {
 		m.term++

internal/quorum/manager_test.go

@@ -119,6 +119,127 @@ func TestDeadAfterEvictsStaleLiveness(t *testing.T) {
 	}
 }
 
+// heartbeatLoop simulates the production heartbeat cadence — calling
+// markLive for the given peers more frequently than deadAfter, so a
+// peer that's "live throughout" never has its liveSince reset by the
+// dead-after gap heuristic. It returns when the context's deadline
+// hits.
+func heartbeatLoop(t *testing.T, m *Manager, dur time.Duration, peers ...string) {
+	t.Helper()
+	deadline := time.Now().Add(dur)
+	interval := m.deadAfter / 4
+	if interval < time.Millisecond {
+		interval = time.Millisecond
+	}
+	for time.Now().Before(deadline) {
+		for _, p := range peers {
+			m.markLive(p)
+		}
+		m.recomputeMaster()
+		time.Sleep(interval)
+	}
+}
+
+func TestReturningLowerIDWaitsForCooldown(t *testing.T) {
+	_, m := threeNode("b")
+	m.deadAfter = 80 * time.Millisecond
+	m.masterCooldown = 200 * time.Millisecond
+
+	// Bootstrap: all three live, "a" elected.
+	m.markLive("a")
+	m.markLive("b")
+	m.markLive("c")
+	m.recomputeMaster()
+	if m.Master() != "a" {
+		t.Fatalf("initial master=%q want a", m.Master())
+	}
+
+	// "a" drops — only b/c heartbeat. Long enough to age a out and let
+	// b take over.
+	heartbeatLoop(t, m, 120*time.Millisecond, "b", "c")
+	if m.Master() != "b" {
+		t.Fatalf("after a-drop master=%q want b", m.Master())
+	}
+
+	// "a" returns. Verify b stays master for less than the cooldown.
+	heartbeatLoop(t, m, 120*time.Millisecond, "a", "b", "c")
+	if m.Master() != "b" {
+		t.Errorf("mid-cooldown master=%q want b", m.Master())
+	}
+
+	// Past the cooldown, a reclaims master.
+	heartbeatLoop(t, m, 120*time.Millisecond, "a", "b", "c")
+	if m.Master() != "a" {
+		t.Errorf("after cooldown master=%q want a", m.Master())
+	}
+}
+
+func TestCooldownResetsOnFlap(t *testing.T) {
+	_, m := threeNode("b")
+	m.deadAfter = 80 * time.Millisecond
+	m.masterCooldown = 200 * time.Millisecond
+
+	m.markLive("a")
+	m.markLive("b")
+	m.markLive("c")
+	m.recomputeMaster()
+
+	// a drops, b becomes master.
+	heartbeatLoop(t, m, 120*time.Millisecond, "b", "c")
+	if m.Master() != "b" {
+		t.Fatalf("master=%q want b", m.Master())
+	}
+
+	// a returns briefly, then drops again before cooldown elapses.
+	heartbeatLoop(t, m, 100*time.Millisecond, "a", "b", "c")
+	if m.Master() != "b" {
+		t.Fatalf("during first cooldown master=%q want b", m.Master())
+	}
+	heartbeatLoop(t, m, 120*time.Millisecond, "b", "c") // a ages out again
+	if m.Master() != "b" {
+		t.Fatalf("after a-reflap master=%q want b", m.Master())
+	}
+
+	// a returns for the second time — cooldown restarts here.
+	// Wait less than a full cooldown — b should still be master.
+	heartbeatLoop(t, m, 100*time.Millisecond, "a", "b", "c")
+	if m.Master() != "b" {
+		t.Errorf("partway through fresh cooldown master=%q want b", m.Master())
+	}
+
+	// Past the full fresh cooldown, a takes over.
+	heartbeatLoop(t, m, 150*time.Millisecond, "a", "b", "c")
+	if m.Master() != "a" {
+		t.Errorf("after fresh cooldown master=%q want a", m.Master())
+	}
+}
+
+func TestNewMasterAfterQuorumLossIgnoresCooldown(t *testing.T) {
+	_, m := threeNode("b")
+	m.deadAfter = 50 * time.Millisecond
+	m.masterCooldown = 1 * time.Hour // would block election if applied
+
+	// Bootstrap into no-master state by letting all peers age out.
+	m.markLive("a")
+	m.markLive("b")
+	m.markLive("c")
+	m.recomputeMaster()
+	time.Sleep(80 * time.Millisecond)
+	m.markLive("b")
+	m.recomputeMaster()
+	if m.Master() != "" {
+		t.Fatalf("master=%q want empty (quorum lost)", m.Master())
+	}
+
+	// Quorum regained — incumbent is empty, election must be immediate.
+	m.markLive("a")
+	m.markLive("b")
+	m.recomputeMaster()
+	if m.Master() != "a" {
+		t.Errorf("post-recovery master=%q want a (no cooldown when empty)", m.Master())
+	}
+}
+
 func TestVersionObserverFiresOnHigherVersion(t *testing.T) {
 	cluster := &config.ClusterConfig{Version: 2}
 	m := New("a", cluster, nil)