Right now, when someone does a search query via webservice, it ties up a perl process as that perl process waits for the search server response, even though it doesn't need to do further processing on the response.

Instead of having the perl code query the webservice search request, it may be possible to have the perl code return a response with the X-Accel-Redirect header to the nginx frontend, and then nginx will redo the request on a new url which will hit the search server directly. The perl is then available to handle the next request immediately.

The X-Accel-Redirect header will contain a URL that must be handled by the nginx server that receives it, and matches against a location that reverse-proxies the search server.