AD Site Count Check
In large environments that contains a lot of sites, can cause a performance issue with Exchange. In particular Autodiscover app pool will peg the CPU at 4-hour intervals when there are many AD sites.
It is recommended to reduce the number of AD Sites within the environment to address this issue. However, there is a workaround that would prevent the issue from occurring every 4-hours and just every 24-hours.
In the %ExchangeInstallPath%\Bin\Microsoft.Exchange.Directory.TopologyService.exe.config file, change the ExchangeTopologyCacheLifetime value to be 1.00:00:00,00:20:00 instead to have the cache lifetime increase from 4-hours to 24-hours. It is not recommended to go beyond 24-hours.
Included in HTML Report?
Yes
Additional resources: