Manual:wgBackendResponseTime

wgBackendResponseTime is the number of milliseconds consumed to serve the page. The value is contained in the HTML of a page similar to this example:

<script>if(window.mw){
mw.config.set({"wgBackendResponseTime":224,"wgHostname":"mw1170"});
}</script>

This has replaced the "served by mw1170 in 224 ms" HTML comment previously provided by MediaWiki, around 1.23.