The error "Jrun closed connection" may be encountered within a ColdFusion application. This is caused by an issue occurring in the JVM, which in turn causes the JVM to close the socket that is open to JRun from the external web server connector, such as IIS, Apache, or iPlanet.
The problem can occur due to several issues, such as:
- outOfMemory or the JVM approaches the max heap
- Native code in a CFX or COM objects causes an error in the JVM
- Socket closed during a restart of the ColdFusion services
JVM memory issues can occur due to several different issues, most commonly:
- Debugging is turned on in production. Make sure debugging is turned completely off on production servers to prevent this from happening.
- Large resultsets are returned from the database, taking up a significant amount of memory. If you cannot allocate additional memory, Macromedia recommends customers reduce the size of their database result sets.
Use the following steps to debug the issue:

