I did this experiment with php apc: In php.ini I set include_path = /first/include/path:/second/include/path, but do not put a file in /first/include/path or /second/include/path, create test.php as simple as this It will run into a fatal error. This error is obvious. Then I create the file tobeincluded.php in /second/include/path, test.php now runs all right. Then… Continue reading When does php apc refresh cache data?