HI All,

I am In trouble..... Need your help...

In my Org, we are using Exchange server 2013 (recently migrated)

Since few Months we are having big problem with the DBs.

Every week Monday Early morning around 3AM to 4AM most of all the DBs are getting failover 

When look into the event logs, it says only....

Event ID 3008

[Eas] Failed to refresh Mailbox server for database *******-07b9-43**-874d-174*****d9 in resource forest (Domain name). Exception: Microsoft.Exchange.Data.Directory.ADTransientException: Could not find any available Domain Controller.
   at Microsoft.Exchange.Data.Directory.ConnectionPoolManager.GetConnection(ConnectionType connectionType, String partitionFqdn, ADObjectId domain, String serverName, Int32 port, NetworkCredential credential)
   at Microsoft.Exchange.Data.Directory.ConnectionPoolManager.GetConnection(ConnectionType connectionType, String partitionFqdn)
   at Microsoft.Exchange.Data.Directory.ADDataSession.GetConnection(String preferredServer, Boolean isWriteOperation, String optionalBaseDN, ADObjectId& rootId, ADScope scope)
   at Microsoft.Exchange.Data.Directory.ADDataSession.GetReadConnection(String preferredServer, String optionalBaseDN, ADObjectId& rootId, ADRawEntry scopeDeteriminingObject)
   at Microsoft.Exchange.Data.Directory.ADDataSession.InternalFind[TResult](ADObjectId rootId, String optionalBaseDN, ADObjectId readId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults, IEnumerable`1 properties, Boolean includeDeletedObjects)
   at Microsoft.Exchange.Data.Directory.ADDataSession.Find[TResult](ADObjectId rootId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults, IEnumerable`1 properties, Boolean includeDeletedObjects)
   at Microsoft.Exchange.Data.Directory.ADDataSession.Find[TResult](ADObjectId rootId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults)
   at Microsoft.Exchange.Data.Directory.SystemConfiguration.ADTopologyConfigurationSession.<>c__DisplayClass1f`1.<FindDatabaseByGuid>b__1e()
   at Microsoft.Exchange.Data.Directory.Diagnostics.ADScenarioLog.InvokeWithAPILog[T](DateTime whenUTC, String name, Guid activityId, String implementation, String caller, Func`1 action, Func`1 getDcFunc)
   at Microsoft.Exchange.Data.Directory.SystemConfiguration.ADTopologyConfigurationSession.InvokeWithAPILogging[T](Func`1 action, String memberName)
   at Microsoft.Exchange.Data.ApplicationLogic.Cafe.MailboxServerLocator.<ResolveMasterServerOrDag>b__11()
   at Microsoft.Exchange.Data.ApplicationLogic.Cafe.MailboxServerLocator.InvokeResourceForest[T](Func`1 adCall)
   at Microsoft.Exchange.Data.ApplicationLogic.Cafe.MailboxServerLocator.ResolveMasterServerOrDag()
   at Microsoft.Exchange.Data.ApplicationLogic.Cafe.MailboxServerLocator.BeginGetServer(AsyncCallback callback, Object asyncState)
   at Microsoft.Exchange.HttpProxy.MailboxServerCache.RefreshDatabase(DatabaseWithForest database)

We are unable to find the cause for this issue..

AD issue may not be possible because we have a redundancy  and all other applications (other than exchange) are working fine..

I also want to know, whether this logs will generate after the DB fail over or due to some issue DB will fail over and this logs will generate??(To narrow down the investigation)

Could any one help in this to resolve the weekly happening DB fail over issue?

Also let me know any information is required.

Thank you, 

Pradeep

• Moved by Jason Johnston [MSFT]Microsoft employee Thursday, July 30, 2015 4:14 PM Not a development question.

A little bit more information might help us to provide you some better resolution.

How much free space on the server? any events prior to the services restarting? what occurs in the area around the server or adjacent walls at that time of day?

Any scheduled tasks running at that time? Is your UPS running a self check at that time? antivirus scan ?

Are you using GFI Products like Mail Essentials or Mail Security?

check for any recent patches and research them to see if there is a problem.

make sure all systems have synched times.

By the way, I would suggest you to look into Lepide health monitoring tool that provides real time reports and helps to get notified for every critical events even at granular level.
Thus, health monitoring alert on server availability, CPU usage and stopping of any Exchange Service will instantly inform an Administrator who in turn can fix the issue before its too late and get rid from such weird circumstances.

Hi Predeep,

Please make sure your DCs are healthy and keep replication properly.

I suggest we can upgrade your Exchange 2013 to the latest version to have a try:

https://support.microsoft.com/en-us/kb/3049849

Regards,