GitHub addresses the challenge of excessive server strain caused by frequent Ajax polling by employing an adaptive strategy using memcached as a message bus. This method involves the web browser polling a server URL to check for new data stored in memcached, with the frequency of polls increasing if no new data is found, potentially adding strain to the site if repeated excessively. To mitigate this, the solution implemented is to incrementally increase the wait time between each poll, reducing unnecessary load. GitHub further streamlined this process by creating a jQuery plugin to facilitate this adaptive polling pattern, known as "smart polling", as evidenced by messages like “Loading commit data…” or “Hardcore Archiving Action” on their platform.