Reconciliation getting failed with fatal error

[Ricky2212]

Reconciliation getting failed with fatal error , validated the SQL accessibility from SSMS from the application server 

Getting error as
ManageSoft.Compliance.Importer.Logic.ComplianceReaderFatalException: 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)
There is a possible connection type mismatch: check that the database is of the correct connection type ---> System.Data.SqlClient.SqlException: 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) ---> System.ComponentModel.Win32Exception: The network path was not found
   --- End of inner exception stack trace ---
   at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling, SqlAuthenticationProviderManager sqlAuthProviderManager)
   at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at ManageSoft.Compliance.Importer.Logic.DatabaseConnection.Open()
   at ManageSoft.Compliance.Importer.Logic.DatabaseSourceConnection.GetVersionReader(String versionQuery)
   at ManageSoft.Compliance.Importer.Logic.DatabaseSourceConnection.ReadVersion(String versionQuery)
   at ManageSoft.Compliance.Importer.Logic.DatabaseSourceConnection.CalculateVersion(ReaderConfig sourceDataType)

 Regards

SJ

[durgeshsingh]

Check DB server services status if everything running fine at DB end then check connectivity from APP Server.

[darren_haehnel]

In our case we have found the cause to be a momentary interruption of network connectivity between the batch and database servers.  Most often these were caused by a firewall failing over to another leg, breaking existing connections.  On another occasion the backup technology we were using caused the network communications on the database server to be "stunned" for long enough to break/time-out existing connections.  Yet another cause was as simple as the DB server being rebooted during a weekend patch cycle in the middle of the job.  

[dhoagland1]

One other possibility I've seen with updates, make sure Named Pipes were not disabled on the DB Server (It's in the Network Configuration tool).