How to force Datatables to re-render or re-load static dat?

Use rows().invalidate() to invalidate data for all rows and draw() to redraw the table.

Please note that 'data' in rows().invalidate('data') is required if you use Javascript data structure (with data or columns.render options).

$('#your_table').DataTable()
   .rows().invalidate('data')
   .draw(false);

You can redraw the entire DataTable on the length.dt event.

$('#your_table').on('length.dt', function (){
     setTimeout(function() {
         //draw('page') redraws your DataTable and preserves the page where it was
         $('#your_table').DataTable().draw('page');
     }, 100);
});

Edit

Here you can see more info and other parameters to pass to the draw method: https://datatables.net/reference/api/draw%28%29