Problem: I have a 2 WFE & 1 App server in my SharePoint 2013 Enterprise Edition SharePoint farm. My WFE 2 and App servers connect all the time to the SQL Server using a SQL alias. My WFE1 server work 80% of the time. It is setup exactly like WFE2 except periodically 1 web app/site collection will stop working and throw the following error:
"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: SQL Network Interfaces, error: 26 - Error
Locating Server/Instance Specified)"
When I log into WFE1 I can connect to SQL using the alias using a udl file and telnet to verify the SQL alias is connected.
Hypothesis/guess: It appears like WFE1 periodically looses networking but only for 1 specific site collection.
Any ideas are most welcome?