While connecting your ASP.NET application to the MSSQL database if you face the below error message.
System.InvalidOperationException: 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.
Which means the database connection has been deleted from the connection pool.
You can try below mentioned solution in order to fix this issue:
Please double check with your application that the database connections are shut down when it is not essential, ASP.NET equipped with garbage collector which can recover the unutilized assets.
Another way is to increase the connection pool size to the connection string, for instance you can set Max Pool Size to 100 in your connection string.
