Changed session durations metric to classic histogram, added

last_activity to calculate monthly active users

4 files changed, 45 insertions, 4 deletions

diff --git a/internal/server/api/api.go b/internal/server/api/api.go
index 5159186..6c602ea 100644
--- a/internal/server/api/api.go
+++ b/internal/server/api/api.go
@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/kyren223/eko/internal/data"
 	"github.com/kyren223/eko/internal/packet"
@@ -1703,3 +1704,17 @@ func DeviceAnalytics(ctx context.Context, sess *session.Session, request *packet
 
 	return nil
 }
+
+func SetLastUserActivity(ctx context.Context, sess *session.Session) {
+	queries := data.New(db)
+	now := time.Now().UnixMilli()
+	err := queries.UpdateUserLastActivity(ctx, data.UpdateUserLastActivityParams{
+		LastActivity: &now,
+		ID:           sess.ID(),
+	})
+	if err != nil {
+		slog.ErrorContext(ctx, "database error", "error", err)
+	} else {
+		slog.DebugContext(ctx, "set user activity", "now", now)
+	}
+}
diff --git a/internal/server/api/migrations/20250718210459_users_last_activity.sql b/internal/server/api/migrations/20250718210459_users_last_activity.sql
new file mode 100644
index 0000000..2fbc2c8
--- /dev/null
+++ b/internal/server/api/migrations/20250718210459_users_last_activity.sql
@@ -0,0 +1,5 @@
+-- +goose Up
+ALTER TABLE users ADD COLUMN last_activity INTEGER;
+
+-- +goose Down
+ALTER TABLE users DROP COLUMN last_activity;
diff --git a/internal/server/metrics/metrics.go b/internal/server/metrics/metrics.go
index d465b6c..e317be6 100644
--- a/internal/server/metrics/metrics.go
+++ b/internal/server/metrics/metrics.go
@@ -56,9 +56,25 @@ var UsersActive = promauto.NewGauge(prometheus.GaugeOpts{
 	Help:      "The total number of active users",
 })
 
+const (
+	Minute = 60
+	Hour   = 60 * Minute
+	Day    = 24 * Hour
+)
+
 var SessionDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
-	Namespace:                   namespace,
-	Name:                        "session_duration_seconds",
-	Help:                        "The duration in seconds of an authenticated session",
-	NativeHistogramBucketFactor: 1.00271,
+	Namespace: namespace,
+	Name:      "session_duration_seconds",
+	Help:      "The duration in seconds of an authenticated session",
+	Buckets: []float64{
+		1, 30, 5 * Minute, 10 * Minute, 30 * Minute,
+		Hour, 2 * Hour, 3 * Hour, 4 * Hour,
+		5 * Hour, 6 * Hour, 7 * Hour, 8 * Hour,
+		10 * Hour, 12 * Hour, 14 * Hour, 16 * Hour,
+		18 * Hour, 20 * Hour, 22 * Hour, Day,
+		2 * Day, 7 * Day, 14 * Day, 28 * Day,
+	},
+	// NativeHistogramBucketFactor:     1.00271,
+	// NativeHistogramMaxBucketNumber:  100,
+	// NativeHistogramMinResetDuration: time.Hour,
 }, []string{"os", "arch", "term", "colorterm"})
diff --git a/internal/server/server.go b/internal/server/server.go
index d94dca6..f38a570 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -528,6 +528,9 @@ func processAuthenticatedRequests(ctx context.Context, sess *session.Session, re
 		response = nil
 	}
 
+	// TODO: add a timeout for this (even tho it should be super fast)
+	api.SetLastUserActivity(ctx, sess)
+
 	return response
 }
 
@@ -690,9 +693,11 @@ func (s *server) handleSessionMetrics(ctx context.Context, sess *session.Session
 		metrics.SessionDuration.WithLabelValues(
 			analytics.OS, analytics.Arch, analytics.Term, analytics.Colorterm,
 		).Observe(duration.Seconds())
+		slog.DebugContext(ctx, "observed session duration", "session_duration", duration.Seconds())
 	} else {
 		metrics.SessionDuration.WithLabelValues(
 			"", "", "", "",
 		).Observe(duration.Seconds())
+		slog.DebugContext(ctx, "observed session duration (empty)", "session_duration", duration.Seconds())
 	}
 }