Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2010-07-29

An indication of an unhealthy Exchange store is that threads are either deadlocked or are otherwise not making progress. If there are more than five threads on a single mailbox, ten threads on a single database, or twenty threads on a single server that haven't progressed in one minute, a time-out is reported on the server. The performance counters that indicate time-outs are:

The Exchange store also writes the following events to the server under the MSExchangeIS source:

If the time-out is detected on a single mailbox, the mailbox is potentially considered to be poisoned and is handled similarly to a failure by increasing the CrashCount property. This action makes the mailbox susceptible to being quarantined. Therefore, you may want to turn off Exchange store time-out detection for Mailbox servers that regularly have a large number of threads operating against them.

Use the Registry to turn off Exchange store time-out detection

Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.
  1. Open Registry Editor (regedit).

  2. Navigate to the following subkey:

    \\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\<Server Name>

  3. Right-click the <Server Name>, point to New, and then click DWORD (32-bit) Value. The new DWORD value displays in the results pane.

  4. Rename the key to DisableTimeoutDetection, and then press Enter.

  5. Right-click DisableTimeoutDetection, and then click Modify.

  6. Change the Value data to 1.

  7. Click OK.