I'm making a WPF application that is data driven and uses dynamic data. Now through the development process on my local computer, everything went fine, the application and my local sql server were functioning perfect.
Now what I did was transfer my database from my local machine to my server, By copying and pasting the database into the SqlServer DATA Folder on my remote server.
Now I'm able to connect to the server just fine, and i made sure to test the connection strings in Visual Studio to make sure it connects, and when i click "Test Connection" it says that the connection was successful.
But now when I try run the application, using the database that is located remotely, I get error:
Sql Exception, Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
And I find it strange because it was working fine 10 minutes ago on my local machine, so I think it must be a setting I have on my remote server or something?
Also I'm using LINQ to SQL, and I've even tried editing the LINQ to SQL Classes (dbml file) and increasing the timeout and such but still get the exact same error. I dont get what I'm doing wrong. Because the whole thing was working not too long ago on my local machine...
Any ideas what the problem is or how I could fix it?
Thanks
This error is generally due to Connection problem between server and the client. There may be a problem in network. Make Sure that database server is accessible from Application machine and no Firewalls are blocking the Connection.
Related
I have an application that runs 24/7 and is connected to an sql database (sql server).
However, the application crashes most night with the following error message
*An existing connection was forcibly closed by the remote host.
*
the db resides on a different server than the application, so I first suspected a network connectivity issue that happened at night.
I ran a script overnight, to ping the db server every 5 minutes and tell me if there were such network connectivity loss, but over the course of 1 week, I only had 1 failed ping.
My next guess is that there could be a database connectivity issue, but i am not sure how I can automate a similar test on the database connection itself (I do not have access to the database server).
I created a UDL file, to test my connection manually (and that works fine), but I would like to such a test to run every 5 minutes overnight, and let me know in a log file, if and when the connection may have failed.
Thanks for your help!
ran script to test network connectivity overnight between appl and db server.
Network connection seems good 24/7 between the application and the db server.
I would now like to run a similar test at 1 or 5 minutes internals on the db connection itself, but I am unaware of how to do that.
I can test manually with a udl file, but I need to help to automate the test and output results in a log file.
Thanks
I have a dotnet exe app in a server which runs in sql server. during the factory production time my application were unable to connect to db for 1 to 2 minutes and then it gains connectivity at this unresponsive time when i accessed sql server management studio, i got the below error:
Taken from the answer over here.
This usually happens when there are too many open transactions that are blocking read access to your database server. You can try restart your server which will usually solve the issue.
I am having an issue at work that is driving me mad. I am new to SQL, and am finding my legs as a system administrator (trial by fire). We have a production server that runs a SQL database and I am trying to mimic the production server in a stand-alone (test) environment. My stand-alone server is of the exact hardware and I have ghosted the production server drives on to the test server (stand-alone) as well. Everything is identical. The only difference is my test server is not in a domain. Its only in a workgroup. My setup consists of one client machine (Windows 7) and the test server running Server 2008r2(SP2)+ SQL Server 2008r2.
We have applications that connect to the database and when I run the applications (connect to the database?), I get 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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 5)
I have been researching this error for about 3 months now. I am at my wits end. I have tried all the solutions I could find. Most of the solutions I found here at this site. Enable remote connections-DONE, Firewall execptions-not necessary as I can disable the firewall since I'm on a standalone network, but I have been down that road before and it did not help. I don't think this is a network issue as I am using just a switch with the server and one client connected. I can ping back and forth between the systems.
I've tried so many other solutions that I cant even remember them all. Changed so many settings I've lost count. Thank goodness I can re-image the server back to normal if I feel I've gone to far and changed too many settings to where I can't remember what I've done.
As you can tell, I probably only make things worse the more I try to fix the error, but I have no choice. Everyone is looking at me to fix this and get the test server working, but I need some help. A huge thank you in advance to anyone that can help me solve this. It would be greatly appreciated!
I use a Microsoft Access 2010 front end with linked tables on an SQL Server 2012 installation. Local network.
When Access Starts, a VBA script runs which connects to the SQL server and performs some checks.
I recently upgraded from SQL Server 2008 to 2012, that's when the connection between client and Server started to fail intermittently.
When the connection between my client and the server fails, I see a generic message "SQL Server does not exist or access denied". This is covered in a Microsoft support article http://support.microsoft.com/kb/328306. The potential causes detailed in that article do not match the trouble I am encountering.
This connection issue is intermittent. The trouble arises about 3 times a week and lasts for about 30 minutes at a time. Between these 30 minute failures, the the system works perfectly.
My Current VBA Connection String: (have tried several, trouble persists with all of them):
Dim conn As ADODB.Connection
Set conn = New ADODB.Connection
conn.Open "Provider=SQLOLEDB;Server=Server3.companydomain.local;Database=My_Database;Trusted_Connection=Yes"
I hope that I can find something in the SQL Server Logs (which I do have access to) but I do not know which Log file to investigate.
I do not have a direct answer to your question, but I believe you could start by exploring the IP and ports on which the SQL server is listening to...Is is possible that the machine using DHCP to assign IP for the DB server as well? In this case I guess it could happen when the IPs are refreshed.
We had a similar issue where multiple IPs were getting assigned on the same machine (having multiple NIC connected) which created such intermittent disruptions.
Well it's been 7 months. Here is the solution for this problem (in my case):
My secondary DNS Server was an external Server. It could not look up my database (192.168.x.x) because this is an internal address.
When My application called the Primary DNS Server to look up the SQL Server address, it worked fine. When my primary DNS was busy, and the application failed over to secondary DNS- the request would time out. There are many reasons someone may see this error. That is the reason I was seeing it.
It's a little strange, but I've found I get this error when I don't have proper "CLOSE DB CONNECTION" type code on my site. And then when too many users hit the site, I start getting this error.
Solution: Do a hard Close of DB connections, after every db call. Yes, most DB Connectors have cleanup routines, but it's not enough under heavy load.
Also, implement a high DB connection limit in the web.config
I have a Delphi application running on SQL Server 2000, but it's taking awfully long to connect to the database!
But when I run this application on my development server it connects pretty fast!
I am running on Windows 2003 server, SQL Server 2k personal edition, when I look on my MDAC version in the registry, I see version 2.8 already installed!
Any ideas why this happens on the production machine but not on the development machine?
There's a reasonable chance that this is down to a network level issue connecting to the database. Depending on whether you're running the application and database on the same box of course.
Try connecting to the database from the same machine using a different tool. You could set up a data source and test it from the control panel as an alternative. If the connection is slow from another tool test the connectivity between the servers for other types of connection (e.g. run a ping). It may be that it's resolving the server via broadcast rather than the domain, for instance. Or any number of other issues - firewall, switch, wins etc.
If you are connecting using integrated authentication also ensure that the database can resolve the application server as well as vice versa. This is part of the authentication process and I've seen it cause slow downs in creating database connections before.
In short, I'd be confident that this isn't a problem specific to delphi / sql, but something in the communications between your production servers.
Good luck!
Keep your connection open once you have established it. This is called connection pooling and will improve performance. I have no clue how to do it with a delphi application.
Your problem most likely is network or transport layer related
Are you connecting through TCP, Named Pipes or another mechanism?
Have you tried tracing opening a connection with Microsoft SQL Profiler?
regards,
Lieven
I had a problem a long time ago like this, and it came down to the workstation section of the connection string. its possible if you've copied the connection string from your dev machine that the workstation parameter is still in the connection string and pointing to your dev machine which probably does not exist on your deployment network.
In this case your connection to the database has to wait until the network tries to connect ot a non-existant machine (which obviously takes time). Remove the workstation cluse and it will speed up no end.