WiceGrid Export Failing

I have Student Table which has more than 15 million records, I am trying to export the data with the WiceGrid export CSV option, but it often timeouts.

What should I do to avoid timing out and giving me the CSV file correctly?

Controller Function

def index
  @students_grid = initialize_grid(
    current_school.students,
    order: 'students.id',
    order_direction: 'desc',
    per_page: 100,
    name: 'g1',
    enable_export_to_csv: true,
    csv_file_name: 'students-' + Time.current.to_s(:number)
  )

  export_grid_if_requested('g1' => 'students_grid') do
  end
end