SQL Server Performance Forum – Threads Archive

Server has been disconnected. . .

Sometimes, when I am working with my remote server using EM, a window called "Microsoft SQL-DMO (ODBC SQLState: 01000)" opens and I get this error message: Error 0: This Server has been disconnected. You must reconnect to perform this operation. This mostly happens when I am trying to browse the server in EM for a Backup destination.
Intresting is that when I check my connection, I am still connected. And if I enter a path and a filename, it works. But if I want to browse the remote drive, I sometimes get the message. The network is sometimes slow with the VPN connection. Do you think, I get some sort of time-out? I have set Query time-out to 600 or even to 0 but still the message sometimes appears. Thanks,
CanadaDBA

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I think the problem is because EM is a GUI tools.
How about Analizer, same problem?
Luis Martin
Moderator
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As it relates to General Network problem, you must try to resolve that issue rather finding solution from SQL Server. As referred by Luis try few statement using Query Analyzer in order to ensure they’re updated. Also confirm what is the status of ‘Boost SQL Server Priority on Windows’ Under the Processes tab of the SQL Server Properties.
Satya SKJ
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As I said the connection is available and I can run queries in QA or even in EM if I enter a path and file name in the Backup Destination window, it works. But if I want to browse for a path or file name in that window, then I get that message [And as I wrote before, this happens sometimes].

CanadaDBA

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Satya, I couldn’t get what you mean about "updated". Regarding ‘Boost SQL Server Priority on Windows’, there is no check mark in the box. My server is a SQL-Server dedicated, should I check the box? What are the advantages and disadvantages in a production environment? Thanks, CanadaDBA

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I mean to say whether you can perform same set of queries.
Areyou getting error 17824 in sql server error log? Satya SKJ
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I’ve just forced the server to generate the error but there is no error in SQL-Server log nor in Application log in server’s Windows event viewer.

CanadaDBA

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Can you check the same statements are working when tried from Query Analyzer. Satya SKJ
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The error occurs when I want to browse the server to find a path as backup destination. How can I do a browse from within the QA? As I mentioned in my first message, if I enter a path in the "Select Backup Destination" window I won’t get the error message and it works. Even if I browse and get the error message, and then close the error window and enter a path and click ok, it works and generates a backup in the specified path.

CanadaDBA

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So are you sure there are no intermittent network issues to reach the server from a client.
EM is flaky sometimes and use the BACKUP statement from Query Analyzer to backup the database and see the results. Satya SKJ
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Yes, I believe the issue is network related because I am able to backup from within EM or QA but I am not able to browse the server’s hard from the ‘Select Backup Destination’ window. Thanks!

CanadaDBA

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Mostly I use QA in order to perform any backups and rarely used EM, because of its flaky behaviour and when you’ve issues of network better to use the script or schedule as a job. HTH Satya SKJ
Moderator
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This posting is provided “AS IS” with no rights for the sake of knowledge sharing.

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I found a strange thing today. I was running a query in QA. It ran completely. Then I tried to run the following: DECLARE @I INT exec @I=master.dbo.xp_cmdshell ‘dtsrun /S 111.222.333.444 /U ServerId /P ServerPassword /N MyDTS’ Then I got the following error: [Microsoft][ODBC SQL Server Driver][DBNETLIB]ConnectionCheckForData (CheckforData()).
Server: Msg 11, Level 16, State 1, Line 0
General network error. Check your network documentation. Connection Broken
This happens while I am able to run the query on the server without any problem. I tried to run the previous query again and it worked perfect. After a few tests, I found that I can not run those queries that have IP address in them. For example, I had a query that creates a stored procedure like this:
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS OFF
GO CREATE PROCEDURE MySP
@RetVal int OUTPUT
AS exec @RetVal=master.dbo.xp_cmdshell ‘dtsrun /S 111.222.333.444 /E /N MyDTS’ GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO GRANT EXECUTE ON [dbo].[MySP] TO [UserId]
GO SET QUOTED_IDENTIFIER ON
GO
SET ANSI_NULLS OFF
GO
and I got same error message. Even if I want to compile it (Pars Query), I get the error. As I’ve told you, I am beyond VPN. I know that the network team had run some patches on the server recently. Do you think this is the cause? I am wonder and confused. CanadaDBA

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Slow connection to an IP could be due to a bug in MDAC 2.6 (even when sql server connects to itself externally via dtsrun). See:
FIX: Connection to SQL Server Database Using IP Address Is Unusually Slow
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q300420&gssnb=1 This sounds very likely if you are on a VPN and name resolution between the servers are not setup. Name resultion between two networks connected through VPN has to be setup manually. Either by adding the entries in DNS on both networks or in the "hosts" files of all involved computers. For example this could be the hosts file of your workstation:
111.222.333.444 SQLSERVER1
111.222.333.555 SQLSERVER2 And on SQLSERVER1 it could be:
111.222.111.222 WORKSTATION
111.222.333.555 SQLSERVER2 Then you use the name to connect and not IP.

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Thanks Argyle,
I’ll check the link and try to fix network connections. But why the QA has problem to compile a query with IP address in it while I don’t have problem to compile a query without any IP address in it? May be my undrestanding of parsing a query is different than what QA does? CanadaDBA

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A number of users have reported: ‘When we attempt to kick off jobs in enterprise manager. We get the message that "The server has been disconnected. You must reconnect to perform this operation". This only happens to both of us when we are VPN’d in.’

anyone seen a fix for this?

The problem also occurs in Query Analyser when any string contains "cmdshell", even in a comment!
This will parse fine:

— cmd shell
print ”

but if I try to parse:

— cmdshell
print ”

it parses fine while at work, but over VPN I get:
[Microsoft][ODBC SQL Server Driver][DBNETLIB]ConnectionCheckForData (CheckforData()).
Server: Msg 11, Level 16, State 1, Line 0
General network error. Check your network documentation.
ODBC: Msg 0, Level 16, State 1
Communication link failure
Connection Broken Bob Sturnfield
[email protected]

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Bob, I would be shocked if this isn’t a network problem. If you have the ability to run Performance Monitor, then start it on the server saving to a trace file. Look for lost and error packets, along with network errors. Your network guys really should be all over this trying to find out what’s wrong, especially if you only have this issue when connected through VPN. The problem could be a lot of things though with VPN in the mix. It could be the server network connection. It could also be a problem with the VPN concentrator. MeanOldDBA
[email protected] When life gives you a lemon, fire the DBA.

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I would look for additional error messages in the Microsoft Event Logs and in the SQL Agent error log. Also check this:
http://groups.google.se/groups?lr=&[email protected] and have you tested adding the servernams to the host files and checked for the MDAC bug mentioned previous in the post?

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