Exchange Database Cache Percent hit false positives

Last Modified

Thu Apr 27 13:31 GMT 2023

Description

• This article details the issue with Exchange Database monitoring where the Database Cache Percent hit returning a value of 0 which is sometimes normal and goes to a failed state.

Environment

• N-able N-central

Solution

• The Database Cache Percent Hit metric indicates the percentage of database file page requests that were fulfilled by the database cache without causing a file operation since the server was started.
  • Reference: Exchange Database 2013 service
• This metric is a static value that is returned from WMI.
• If the value being pulled up is 0, we'd like to think that there is no cache being used.
• Here is a bit more information about the service from Microsoft:
  • https://docs.microsoft.com/en-us/previous-versions/office/exchange-server-2010/ee832793(v=exchg.141)
• It seems Exchange 2013 will sometimes use the database cache hit and other times it simply won't.
• The hit percent will be 0 if the exchange server is not busy, so the value=0 can sometimes be normal.
• To check the value reported by WMI on the device

1. From the Windows Start menu, click Start > Run.
2. Type wbemtest and select OK.
   • NOTE: You need to make sure to run wbemtest in admin
3. Select Connect.
4. Type root\cimv2 in the Namespace field.
5. Select Connect.
6. Select Enum Classes.
7. Select Recursive.
8. Select OK.
9. Search for the WMI class that you want to view.
   • In this case it is 'Win32_PerfFormattedData_ESE_MSExchangeDatabase'
10. Double-click Win32_PerfFormattedData_ESE_MSExchangeDatabase
11. Select Instances.
12. Select the Instance in question.

• If it is reporting a 0 then N-able N-central is reporting as it should,
• If it is not reporting a 0 then please open a support case and provide a screenshot, referencing this article number (000036641),