How does the rule EXC IS Database Cache Percent Hit work (4275144)

Rule “EXC IS Database Cache Percent Hit” monitors the performance counter MSExchange Database(Information Store)\Database Cache % Hit. As per Microsoft’s documentation, the hit percent should be over 90% for companies with majority online mode clients. An alarm will be fired if the current value is below 90% .

Please check "MSExchange Database(Information Store)\Database Cache % Hit" details in “Database Counter” section in below MSDN documents:

Monitoring Mailbox Servers

Mailbox Server Counters

Note: MSExchange Database(Information Store)\Database Cache % Hit perf counter in Exchange 2013/2016 works the same way as in Exchange 2010.