var watch_path = '/var/lib/mysql/appname/*.ibd'
var watcher = chokidar.watch(watch_path,{
     ignored: /(^|[/\])../,
     ignorePermissionErrors: true,
     //usePolling: true,  ...works if not commented out
         // interval: 100,      ..., setting for polling
     persistent: true
})
// Add event listeners.
var log = console.log.bind(console);
watcher.on('change', path => log(`${path} changed`, server_timestamp_now()))