XADM: Exchange Server May Appear to Hang With Non-Responsive Domain Controller

The Microsoft Exchange Information Store service may appear to stop responding (hang). New clients may be unable to log on. If this is a virtual server for a cluster, a cluster failover may occur.

The information store relies on DSAccess to query directory services. DSAccess uses Wldap32.dll to query directories, and relies on Wldap32.dll to return an error if a time-out is exceeded during normal operation.

If the Lightweight Directory Access Protocol (LDAP) server (domain controller) cannot receive more data from the client (store) because the server-side data buffers are full, Wldap32.dll may loop forever trying to submit more data. The typical time-out logic does not apply to this condition.

To resolve this problem, obtain the latest service pack for Microsoft Exchange 2000 Server. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: A new Wldap32.dll option (LDAP_OPT_SEND_TIMEOUT) has been created that allows Wldap32.dll to end a loop when the receiving end cannot receive more data. This fix includes an updated Dsaccess.dll file that takes advantage of this new Wldap32.dll option. The English version of this fix should have the following file attributes or later:

Component: Information Store


NOTE: Because of file dependencies, this update requires Microsoft Exchange 2000 Server Service Pack 2.

Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server. This problem was first corrected in Microsoft Exchange 2000 Server Service Pack 3.