As applications are promoted from the development environment to the CI or the QA environment and then into the production environment, it is very common for the configuration settings to be changed as the code is promoted. For example, the settings for the database connection pools are typically lower in development environment than the QA/Load Testing environment. The primary reason for the existence of the configuration setting differences is to enhance application performance. However, occasionally there are instances where the application code is mistakenly promoted into production without changing these settings. In such cases, such promotion of code can cause performance havoc in the production environment. This blog describes one such scenario.