PHP Manual: Return information about open and cached links

array mysqli_get_links_stats()

mysqli_get_links_stats returns information about open and cached MySQL links.

This function has no parameters.

mysqli_get_links_stats returns an associative array with three elements, keyed as follows:

total: An int indicating the total number of open links in any state.
active_plinks: An int representing the number of active persistent connections.
cached_plinks: An int representing the number of inactive persistent connections.