Fix/delete old snapshot (SigNoz#1621)

* fix: remove old snapshots

ee/query-service/usage/manager.go

@@ -139,6 +139,8 @@ func (lm *Manager) UsageExporter(ctx context.Context) {
 			lm.CollectAndStoreUsage(ctx)
 		case <-uploadTicker.C:
 			lm.UploadUsage(ctx)
+			// remove the old snapshots
+			lm.repository.DropOldSnapshots(ctx)
 		}
 	}
 }

ee/query-service/usage/repository/repository.go

@@ -17,6 +17,7 @@ import (
 
 const (
 	MaxFailedSyncCount = 9 // a snapshot will be ignored if the max failed count is greater than or equal to 9
+	SnapShotLife       = 3 * 24 * time.Hour
 )
 
 // Repository is usage Repository which stores usage snapshot in a secured DB
@@ -111,6 +112,18 @@ func (r *Repository) GetSnapshotsNotSynced(ctx context.Context) ([]*model.Usage,
 	return snapshots, nil
 }
 
+func (r *Repository) DropOldSnapshots(ctx context.Context) error {
+	query := `delete from usage where created_at <= $1`
+
+	_, err := r.db.ExecContext(ctx, query, time.Now().Add(-(SnapShotLife)))
+	if err != nil {
+		zap.S().Errorf("failed to remove old snapshots from db: %v", zap.Error(err))
+		return err
+	}
+
+	return nil
+}
+
 // CheckSnapshotGtCreatedAt checks if there is any snapshot greater than the provided timestamp
 func (r *Repository) CheckSnapshotGtCreatedAt(ctx context.Context, ts time.Time) (bool, error) {