fix issues TUI display reliability

README.md

@@ -371,6 +371,33 @@ to Docker or stored in the image.
 - `OTEL_CLICKHOUSE_DB` / `OTEL_CLICKHOUSE_USER` /
   `OTEL_CLICKHOUSE_PASSWORD` - optional ClickHouse connection settings
   (defaults: `otel` / `default` / empty).
+
+### Issues display
+
+The standalone `issues-tui` command is a terminal dashboard for currently
+firing alert spikes. It reads normalized error events directly from
+ClickHouse; it does not replace the web UI's persisted `/api/issues` view.
+
+Build and run it on the display computer (or use `go run`):
+
+```sh
+go build -o issues-tui ./cmd/issues-tui
+OTEL_CLICKHOUSE_ADDR=clickhouse.example.net:9000 \
+OTEL_CLICKHOUSE_DB=otel \
+OTEL_CLICKHOUSE_USER=default \
+OTEL_CLICKHOUSE_PASSWORD='…' \
+OTEL_ALERT_BASE_URL=https://otel.example.net \
+./issues-tui
+```
+
+The display computer must be able to reach ClickHouse's native TCP port. For a
+Kubernetes-only ClickHouse service, use a private network path or tunnel; the
+in-cluster service name is not reachable from an ordinary workstation. The
+dashboard refreshes using the `OTEL_ALERT_*` interval, window, baseline,
+cooldown and lag settings. Press `r` to scan immediately and `q` to quit.
+Use `-once` for a one-shot, non-interactive output suitable for a process
+supervisor health check.
+
 - `OTEL_INGEST_KEY` - optional shared key required (via `?key=` or the
   `X-Otel-Ingest-Key` header) on `/v1/traces`, `/v1/metrics` and `/v1/logs`
   over HTTP. Unset by default (no key required). This is meant to

cmd/issues-tui/main.go

@@ -155,6 +155,10 @@ func spikeKey(s features.Spike) string {
 	return s.Service + "\x00" + strings.Join(sigs, "\x00")
 }
 
+func patternKey(service, signature string) string {
+	return service + "\x00" + signature
+}
+
 // Scan runs one evaluation, mirroring the runner's Tick: load the window
 // ending lag ago plus its baseline, detect exactly what the server pages on,
 // and use a cooldown suppressor to tell a fresh page from an ongoing one.
@@ -184,9 +188,11 @@ func (s *scanner) Scan(ctx context.Context, now time.Time) snapshot {
 	// The suppressor mutates only its own state and the copies Filter makes,
 	// so firing keeps every pattern for display while paged marks what would
 	// have been sent to Telegram / the webhook.
-	pagedKeys := map[string]bool{}
+	pagedPatterns := map[string]bool{}
 	for _, sp := range s.pager.Filter(firing) {
-		pagedKeys[spikeKey(sp)] = true
+		for _, p := range sp.Patterns {
+			pagedPatterns[patternKey(sp.Service, p.Signature)] = true
+		}
 	}
 
 	nowActive := map[string]bool{}
@@ -198,7 +204,14 @@ func (s *scanner) Scan(ctx context.Context, now time.Time) snapshot {
 			first = end
 			s.active[key] = first
 		}
-		snap.Issues = append(snap.Issues, issueView{alert: alerts.NewAlert(sp, end), key: key, paged: pagedKeys[key], firstSeen: first})
+		paged := false
+		for _, p := range sp.Patterns {
+			if pagedPatterns[patternKey(sp.Service, p.Signature)] {
+				paged = true
+				break
+			}
+		}
+		snap.Issues = append(snap.Issues, issueView{alert: alerts.NewAlert(sp, end), key: key, paged: paged, firstSeen: first})
 	}
 	for key, first := range s.active {
 		if !nowActive[key] {

cmd/issues-tui/main_test.go

@@ -251,3 +251,26 @@ func TestBarAndMinimal(t *testing.T) {
 		t.Fatalf("minimal render should surface scan errors, got %q", got)
 	}
 }
+
+func TestModelKeepsLastGoodSnapshotOnScanError(t *testing.T) {
+	m := newModel(nil, modelConfig{Interval: time.Minute})
+	good := snapshot{ScannedAt: time.Now(), Issues: []issueView{{}}}
+	updated, _ := m.Update(snapshotMsg(good))
+	m = updated.(model)
+
+	failed := snapshot{Err: context.DeadlineExceeded}
+	updated, _ = m.Update(snapshotMsg(failed))
+	m = updated.(model)
+	if len(m.snap.Issues) != 1 {
+		t.Fatalf("failed scan should not erase the last good snapshot: %+v", m.snap)
+	}
+	if m.scanErr == nil {
+		t.Fatal("failed scan should be visible separately from the last good snapshot")
+	}
+
+	updated, _ = m.Update(snapshotMsg(snapshot{ScannedAt: time.Now()}))
+	m = updated.(model)
+	if m.scanErr != nil {
+		t.Fatal("successful scan should clear the previous scan error")
+	}
+}

cmd/issues-tui/tui.go

@@ -25,6 +25,9 @@ type model struct {
 	sc   *scanner
 	cfg  modelConfig
 	snap snapshot
+	// scanErr is kept separately so a failed refresh does not erase the last
+	// successful data from the display.
+	scanErr error
 
 	scanning   bool
 	nextScanAt time.Time
@@ -79,7 +82,13 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		return m, cmd
 
 	case snapshotMsg:
-		m.snap = snapshot(msg)
+		snap := snapshot(msg)
+		if snap.Err != nil {
+			m.scanErr = snap.Err
+		} else {
+			m.snap = snap
+			m.scanErr = nil
+		}
 		m.scanning = false
 		m.nextScanAt = time.Now().Add(m.cfg.Interval)
 		return m, nil
@@ -90,6 +99,6 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 func (m model) View() string {
 	return renderSnapshot(m.snap, snapshotOptions{
 		Width: m.width, Height: m.height, Title: m.cfg.Title, BaseURL: m.cfg.BaseURL,
-		Scanning: m.scanning, NextScanAt: m.nextScanAt, Now: time.Now(),
+		Scanning: m.scanning, NextScanAt: m.nextScanAt, Now: time.Now(), ScanError: m.scanErr,
 	})
 }

cmd/issues-tui/view.go

@@ -34,6 +34,7 @@ type snapshotOptions struct {
 	Scanning      bool
 	NextScanAt    time.Time
 	Now           time.Time
+	ScanError     error
 }
 
 // Colors mirror the otel-ui design-system tokens (AGENTS.md) so the terminal
@@ -87,6 +88,9 @@ func renderBody(snap snapshot, o snapshotOptions, w, avail int) string {
 	case snap.Err != nil:
 		return statusPanel(w, min(avail, 5), colCritical, "SCAN FAILED", snap.Err.Error(),
 			"values are from "+fmtTime(snap.ScannedAt)+"; the display keeps the last good scan")
+	case o.ScanError != nil && len(snap.Issues) == 0:
+		return statusPanel(w, min(avail, 5), colCritical, "SCAN FAILED", o.ScanError.Error(),
+			"no successful scan yet; retrying automatically")
 	case len(snap.Issues) == 0:
 		sub := fmt.Sprintf("no issues firing · window %s–%s UTC · scanned %s",
 			snap.WindowStart.Format("15:04"), snap.WindowEnd.Format("15:04"), commas(snap.Events))
@@ -234,6 +238,9 @@ func renderHeader(snap snapshot, o snapshotOptions) string {
 	title := style(colAccent, true).Render(strings.ToUpper(o.Title))
 
 	left := []string{title}
+	if o.ScanError != nil {
+		left = append(left, style(colCritical, true).Render("SCAN FAILED"))
+	}
 	if !snap.WindowEnd.IsZero() {
 		left = append(left, style(colText3, false).Render(
 			fmt.Sprintf("%s–%s UTC", snap.WindowStart.Format("15:04"), snap.WindowEnd.Format("15:04"))))