Today I came across a very odd issue in that an exchange mailbox server started throwing up events in the application log refering to Active Directory GC information. This started at a random time and no AD changes had recently been made. This also was occuring on only one of two mailbox servers in the same site. The events that were most frequent were the following:
Source: MSExchangeADTopology EventID: 2070
Source: MSExchangeSA EventID: 9144
Along with the above events, my software method of using ESE and copying the transction logs with a third part product was failing at every attempt.
Some of the warnings during this process logged the following events:
Source: ESE EventID: 222
Source: ESE EventID: 215
End user experience was that of Outlook clients loosing connectivity to the server intermittently.
We spent hours trying to track down the problem without rebooting the mailbox server and never determining the root cause. We also knew that nothing had changed in Active Directory that would cause one of two mailbox servers to complain about every GC in the local site.
All symptoms pointed to a networking related issue on the mailbox server. After disabling TCPchinmey which is part of the Scalable Network Pack in Server 2003 SP2 and enabled by default, the warnings stopped and all was well again. Contrary to what I thought, the server did NOT have to be restarted after disabling it via the registry. In case anyone needs it, the location of the key is;
Change the value in the EnableTCPChimney key from 1 to 0.