Tons of Cannot Find SQL Server errors in ULS log

Question

Background: I inherited the maintenance of this farm. The previous consultant migrated the client from WSS 3.0 to 2013 by way of 2007 MOSS and 2010 (unsure of version). I do not know if there was a "temporary" SQL server used during this process
that no longer exists. It seems likely given all of the errors regarding a missing SQL server.
The current 2013 Enterprise farm contains 1 WFE and 3 App servers, 2 of which comprise the search topology. There is one SQL server, not aliased. All machines are VMs. One of the search servers (App) is on a different ESXi host. The timer job that is creating
all of the ULS errors is running on the WFE. Beyond that, the farm has these symptoms:
It "works" albeit very slowly. Crawl rate of 2-7 dps for both external file shares and the SP content (both with and without Task Offloading / Chimney Offloading enabled). It seems to frequently recycle or take an otherwise long time to render
in the browser (any page). Finally, it  spews tens of thousands of errors 24x7 on the WFE saying a SQL server (unnamed) cannot be contacted via Named Pipes.
Specifically: "Unknown SQL Exception 53 occurred. Additional error information from SQL Server is included below.  A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)".
The next error in the sequence is: "An internal error occurred while running a timer job: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that
the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject,
UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)..."
This is followed by an error such as this: "There was an internal error invoking the timer job '{E4DDC92E-0056-4E7E-BD3F-1CF5670ACB7D}' for service '{6105D588-FB34-4F1C-82F6-479D7FE146EA}'."
Of course, each time the timer job mentioned is different. 
One more error appears consistently with these although not as frequently: "The Execute method of job definition Microsoft.SharePoint.Diagnostics.SPDiagnosticsMetricsProvider (ID 36e6942a-9a80-440f-94a4-e4a606362734) threw an exception. More information
is included below.  Connection Timeout Expired.  The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement.  This could be because the pre-login handshake failed or the server was unable to respond back in
time.  The duration spent while attempting to connect to this server was - [Pre-Login] initialization=21276; handshake=0;"
I have been troubleshooting this for days but am not making much progress. How can I determine just what SQL server it says it cannot find and where that server name is stored? It seems like it has to be part of the Timer job configuration since the two
things are related.

Answer 1

Hi,
Thanks for your sharing and have a good day.
Jason
Jason Guo
TechNet Community Support