Re: Connection timeout

Ah, no. The Connection Pool is a mechanism on the CLIENT, not the server. Typically connection timeouts are caused by either:
1.. Not closing connections. For example, if your routine opens a connection, executes a query that throws an exception, the Close might not get called. You might also be handing a DataReader to another routine that does not (or cannot) close the Connection.
2.. Overloading the server. If the application is pressed so hard that it can't get the job done in the time available (before another operation begins), another Connection is created. This can easily snowball and fill the Connection Pool.
You can't really share a live connection across processes. You can share the ConnectionString, but not the Connection class. Each process gets its own pool.

See Chapter 9 and my article on handling the Connection Pool on my website. http://www.betav.com/sql_server_magazine.htm

hth

--
____________________________________
William (Bill) Vaughn
Author, Mentor, Consultant
Microsoft MVP
INETA Speaker
www.betav.com/blog/billva
www.betav.com
Please reply only to the newsgroup so that others can benefit.
This posting is provided "AS IS" with no warranties, and confers no rights.
__________________________________
Visit www.hitchhikerguides.net to get more information on my latest book:
Hitchhiker's Guide to Visual Studio and SQL Server (7th Edition)
and Hitchhiker's Guide to SQL Server 2005 Compact Edition (EBook)
-----------------------------------------------------------------------------------------------------------------------

"DCraig" <dcraig@xxxxxxxxxx> wrote in message news:OjccXO1MHHA.4708@xxxxxxxxxxxxxxxxxxxxxxx
I'm having a problem with one of my forms (using .Net 03 EE, SQL 2K
Standard, XP client and Windows Server03). After editing and deleting a few
records, the form starts timing out, giving me the message;

"Timeout expired. The timeout period elapsed prior to obtaining a
connection from the pool. This may have occurred because all pooled
connections were in use and max pool size was reached."

Once this happens, I cannot connect to the database until I restart the
application. At the same time, I can connect to the database fine from
another application (query analyzer) or even another copy of the same
application. I understood that the 'connection pool' was a resource on the
server, not part of ADO .Net, but either the message is complete nonsense or
each instance of the application has a limited pool of connections?

I've managed to improve the situation by sharing a connection across the
tiers and passing it by reference, but I still get the message after editing
10 or so records rather than 3. I've been going over the code to be sure
that connections are being closed and transactions are terminating and it
all looks like it should: the connection is being closed in 'finally' as
recommended, previous transactions are terminating successfully.

I've monitored the connections on the server, and typically there are 40 to
60 connections (this includes connections to the live database as well as
our development copy) and 10 to 20 pools. From what I've read this is more
than sufficient, the number does not change significantly when the exception
occurs.

Has anyone seen this? Can anyone help me understand if this has to do with
the connection pool or if the message is a wild goose chase?

Thanks;

David Craig.

Relevant Pages

  • Re: web serivce: client side timeout?
    ... client side but only from the server side. ... System.Net.Sockets.SocketException: A connection attempt failed ... asyncResult, Int32 timeout, Exception& exception) ... John Saunders | MVP - Windows Server System - Connected System ...
    (microsoft.public.dotnet.framework.webservices)
  • Re: Timeout expired. The timeout period elapsed prior to completion of the operation or the server i
    ... This does not look like a Connection Pool issue--the message returned by the ... errors are traditionally caused when SQL Server is loaded beyond capacity. ... Message: Timeout expired. ... it appears that this error is more of a TCP/IP type ...
    (microsoft.public.dotnet.framework.adonet)
  • Re: Outlook and Outlook Express die....after a while.
    ... >> Your server has unexpectedly terminated the connection. ... with as little as 4% packet loss. ... tolerant so it doesn't look to be a server-side timeout problem during ...
    (microsoft.public.windows.inetexplorer.ie6_outlookexpress)
  • Re: detecting the (brute) disconnection of a client
    ... crashed, and if an exception occurs, then the client is deconnected. ... You can either use the timeout itself as an indication of connection failure, or you can attempt to send data after the timeout. ... The server has no way to know if the connection has failed due to a client-side crash, or simply due to a temporary problem with the network. ... IMHO, it would be better to simply let the server continue to assume that the connection is valid unless there is some explicit, non-arbitrary verification that it's not. ...
    (microsoft.public.dotnet.languages.csharp)
  • Re: Sendmail + DoS???
    ... carefully examining the behaviour of the server for those mails, ... which enforces a timeout at this stage: ... Throtle and connection rate limit are solutions for that. ... I use milter-error to stop the kind of dictionary attacks that include ...
    (comp.mail.sendmail)