XADM: Event ID 8512 Logged by Exchange Server Information Store

An Exchange Server computer may periodically generate the following event ID 8512 error message (which indicates that error 3034 occurred) in the Application event log:

This issue occurs because the Exchange Server information store process creates threads to use when sending and receiving mail from the Exchange Server message transfer agent (MTA). The number of threads that are created is determined by a number of registry values, and these registry values are ordinarily set based on adjustments that are made when you run the Exchange Server Performance Optimizer (Perfwiz).

If these registry values are set manually to values that exceed 40 when the values are added together, the information store generates the event ID 8512 error message (which indicates error 3034) in the "Symptoms" section of this article.

To resolve this issue, run Performance Optimizer to reset the registry values to values that do not add up to more than 40.

You can determine the total number of threads that the information store uses to communicate with the MTA by adding the following registry values together:

• Under the following registry key:
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersPrivate
  • Send Threads
  • Delivery Threads
  • Gateway In Threads
  • Gateway Out Threads
• Under the following registry key:
  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersPublic
  • Send Threads
  • Delivery Threads

Add 1 or 2 to the sum of the preceding values to account for the internal information store process that flushes the e-mail messages of users that are being moved.

If this total number of threads exceeds 40 for Exchange Server 5.5, the information store process logs the event ID 8512 error message in the Application event log.