SQL Instance is Unreachable - Cannot Connect

SQL Server performance monitoring and alerting

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SQL Instance is Unreachable - Cannot Connect

Postby PDI » Thu Apr 24, 2014 10:30 am

Hi,

I have a straightforward Next/Next installation of Monitor 4.
Base and Web installed on same Server 2008 R2.
All settings default.

The Monitor can connect to the SQL Host.
But it cannot connect to the Instance.

From the Base/Web server I connect using a different domain account.
The domain account is the same for the SQL Host and the SQL Instance though.
I provide credentials.
The SQL Host is OK - monitored.
The SQL Instance on that host is not monitored due to the Unreachable error.

The account I use for connecting to the SQL Instance has the following:
db_datareader on msdb
SQLAgrentRader on msdb
db_ddladmin on tempdb (this is optional but I have added this out of frustration and due to another thread on this forum saying it must be enabled even thoguh the DOC says different)
VIEW ANY DEFINITION on server
VIEW SERVER STATE on server
VIEW DATABASE STATE on specific databases (for testing in the start)

I have not enabled ALTER TRACE or sysadmin (as these are optional)

I have enabled db_reader, db_writer, db_ddladmin on tempdb (as another thread mentions).

From the computer hosting Base/Web server I can connect to the SQL instance using SSMS and see the expected databases etc.
So I can ping and I can use SSMS as expected.

Still SQL Monitor 4 cannot connect to the SQL Instance on the SQL Host it can connect to.

Please help :-)
PDI
 
Posts: 3
Joined: Thu Apr 24, 2014 10:20 am

Postby Brian Donahue » Fri Apr 25, 2014 1:40 pm

What does it say is the cause of the failure when you click the "show log" link next to the status in Configuation->Monitored servers?
Brian Donahue
 
Posts: 6670
Joined: Mon Aug 23, 2004 10:48 am

Postby PDI » Mon Apr 28, 2014 1:54 pm

Hi Brian Donahue,

it says:

"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)"

Since this is the error I have google it and it says:
http://blog.sqlauthority.com/2009/05/21 ... ver-error/

Please acknowledge that this is the actual cause since I would regret changes some settings I dont really know what does.

Thanks.
PDI
 
Posts: 3
Joined: Thu Apr 24, 2014 10:20 am

Postby Brian Donahue » Mon Apr 28, 2014 3:38 pm

There is still not enough information to confirm any root cause of this. Typical problems are:
  • SQL Server does not allow remote connections
  • Firewall blocking SQL port(s) and/or protocols
  • SQL Browser service not running on the SQL Server computer


Particularly if the SQL Server is using a custom port or is a named instance, you will need SQL Browser to be running, otherwise a client is unable to know how to connect to it by name. As above, you also have to allow UDP port 1434 through the firewall or the browser information will not be retrieved.
Brian Donahue
 
Posts: 6670
Joined: Mon Aug 23, 2004 10:48 am

Postby PDI » Fri May 02, 2014 8:55 am

Hi,

the error was that our SQL server was not using the default port for TCP/IP.
Since the SQL is in production I cannot change this.
I have then removed and added the SQL\\SQL host and instance again using a custom port and this works.
I am still having some problems but I am in touch with Red Gate support.

Thank you for your answers Brian Donahue.
PDI
 
Posts: 3
Joined: Thu Apr 24, 2014 10:20 am


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