Application errors fixed with an IIS reset/Memory hanging
Posted on 2005-04-27
Our project recently upgraded our .NET Web Application to a new server. The old server was Windows 2000 using IIS 5.0, dual processor, using an Oracle 8i database on a separate server and .NET 1.1. The new server is Windows 2003 using IIS 6.0, quad processor, using an Oracle 9i database on a separate server and .NET 1.1. Both connect to Oracle using the ODP.NET v 184.108.40.2062 driver. All software is updated regularly to include the latest service packs and/or patches. This web server is also running several other small web applications. Since we have migrated to the new environment we have experienced multiple issues and performance problems and we are trying to pull apart each piece of technology being used to identify the culprit(s).
When we moved to IIS 6.0, we kept all of the default settings, including memory. Our software consists of over 550 pages, many which make extensive use of the database using extremely complex queries and logic. Our pages consist of about 1/3 selection pages, 1/3 reports and 1/3 update screens. The reports can return large datasets, sometimes up to 4000 records.
We are periodically experiencing TNS errors on some of our application pages. First, we logged a help call with Oracle and after several dump files and conversations they determined the problem was not from within the database but was occuring in the calling application. Next, we logged a help call with Microsoft. It seems the way we were connecting to the database was not using Best Practices, although wasn't incorrect. Either way, we are currently in the process of recoding all of our pages to use Microsoft's best practices.
What we are experiencing now is that a particular page will throw a TNS error. Once the page throws the error, the page becomes unuseable until we either a) recode the page or b) reset IIS. What we see though is that we only see this TNS error on one particular page over and over again. Once we recode that page, a new page which had been operating fine before now gets a TNS error.
Additionally, there are several other web applications being run on this web server that are unaffected by the transition.
Why would the software behave differently in our new environment and why would the error seem to randomly appear on a particular page? Also, is there a less invasive method to clearing memory other than resetting IIS?