improve logging and concurrent vcenter inventory

db/helpers.go

@@ -75,7 +75,12 @@ func getLog(ctx context.Context, dbConn *sqlx.DB, dest interface{}, query string
 			slog.Debug("db get returned no rows", "query", strings.TrimSpace(query))
 			return err
 		}
-		slog.Warn("db get failed", "query", strings.TrimSpace(query), "error", err)
+		// Soften logging for timeout/cancel scenarios commonly hit during best-effort probes.
+		if errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled) {
+			slog.Debug("db get timed out", "query", strings.TrimSpace(query), "error", err)
+		} else {
+			slog.Warn("db get failed", "query", strings.TrimSpace(query), "error", err)
+		}
 	}
 	return err
 }
@@ -83,7 +88,11 @@ func getLog(ctx context.Context, dbConn *sqlx.DB, dest interface{}, query string
 func selectLog(ctx context.Context, dbConn *sqlx.DB, dest interface{}, query string, args ...interface{}) error {
 	err := dbConn.SelectContext(ctx, dest, query, args...)
 	if err != nil {
-		slog.Warn("db select failed", "query", strings.TrimSpace(query), "error", err)
+		if errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled) {
+			slog.Debug("db select timed out", "query", strings.TrimSpace(query), "error", err)
+		} else {
+			slog.Warn("db select failed", "query", strings.TrimSpace(query), "error", err)
+		}
 	}
 	return err
 }
@@ -395,6 +404,7 @@ func ApplySQLiteTuning(ctx context.Context, dbConn *sqlx.DB) {
 		`PRAGMA synchronous=NORMAL;`,
 		`PRAGMA temp_store=MEMORY;`,
 		`PRAGMA optimize;`,
+		`PRAGMA busy_timeout=5000;`,
 	}
 	for _, pragma := range pragmas {
 		_, err = execLog(ctx, dbConn, pragma)
@@ -404,6 +414,20 @@ func ApplySQLiteTuning(ctx context.Context, dbConn *sqlx.DB) {
 	}
 }
 
+// CheckpointSQLite forces a WAL checkpoint (truncate) when using SQLite. No-op for other drivers.
+func CheckpointSQLite(ctx context.Context, dbConn *sqlx.DB) error {
+	if strings.ToLower(dbConn.DriverName()) != "sqlite" {
+		return nil
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	cctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	_, err := dbConn.ExecContext(cctx, `PRAGMA wal_checkpoint(TRUNCATE);`)
+	return err
+}
+
 // EnsureVmHourlyStats creates the shared per-snapshot cache table used by Go aggregations.
 func EnsureVmHourlyStats(ctx context.Context, dbConn *sqlx.DB) error {
 	ddl := `