If you are working with .NET applications, at some time you might get the below (or similar) error 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.
Why you get the connection pool timeout error
The most probable reason you are getting the above error message, is that your application opens connection to the database without closing them. This situation is then repeated and after a number of times, the application throws an exception because it cannot open more than a given number (max pool) of connections to the database.
The best practice is to let .NET do the connection handling for you by running your SQL queries with the “using” statement. Here’s a C# example:
using (SqlConnection conn = new SqlConnection(connString))
{
SqlCommand cmd = new SqlCommand("SELECT @@VERSION", conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
//process the result
dr.Close();
}
}
There is a useful MSDN blog article (a little old but the principle is the same), which has more info about this type of connection handling in .NET.
Get the help you need for getting started with .NET Programming!
(Lifetime access, certificate of completion and more!)
Learn how to implement Windows Forms projects in .NET using Visual Studio and C#, how to implement multithreading, how to create deployment packages and installers for your .NET Windows Forms apps using ClickOnce in Visual Studio, and more!
Many live demonstrations and downloadable resources included!
Artemakis Artemiou is a Senior SQL Server Architect, Author, and a 9 Times Microsoft Data Platform MVP (2009-2018). He has over 15 years of experience in the IT industry in various roles. Artemakis is the founder of SQLNetHub and TechHowTos.com. Artemakis is the creator of the well-known software tools Snippets Generator and DBA Security Advisor. Also, he is the author of many eBooks on SQL Server. Artemakis currently serves as the President of the Cyprus .NET User Group (CDNUG) and the International .NET Association Country Leader for Cyprus (INETA).
This site uses cookies for personalized content and the best possible experience. By continuing to browse this site, you agree to this use. Find out more.