500 Internal Server Error

Client was getting following error while accessing the form application.

500 Internal Server Error
java.io.IOException: Too many open files at java.io.FileInputStream.open(Native Method) at java.io.FileInputStream.(FileInputStream.java:106) at java.io.FileInputStream.(FileInputStream.java:66) at java.io.FileReader.(FileReader.java:41) at oracle.forms.servlet.ConfigFileParser.(Unknown Source) at oracle.forms.servlet.FormsServlet.doRequest(Unknown Source) at
oracle.forms.servlet.FormsServlet.doGet(Unknown Source) at javax.servlet.http.HttpServlet.service(HttpServlet.java:740) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:835) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:341) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:816) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:231) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:136) at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192) at java.lang.Thread.run(Thread.java:534)

 Cause
On Windows systems , there is a limit to the number of files that can be simultaneously opened : about 2000.
This limit applies to all the servlets running in the OC4J_BI_Forms : The forms Servlets and the Reports Servlets.
Solution
To increase the parameter numprocs for the OC4J_BI_Forms :

1. Edit the file ORACLE_HOME\opmn\conf\opmn.xml

2. Locate the following lines :
....
process-type id="OC4J_BI_Forms" module-id="OC4J">
....
process-set id="default_island" numprocs="1"/>
/process-type>
.....


3. Replace :
numprocs="1"
by
numprocs="2"

4. Execute the command :
$ORACLE_HOME/bin/opmnctl reload
in order to reload the file opmn.xml

The modification will be taken into account the next time the OC4J_BI_Forms will be restarted.

When numprocs > 1 , several processes will be started for the OC4J OC4J_BI_Forms. It means that the requests will be "load-balanced" between the 2 processes.
So, the number of files opened will be divided by 2 (if numprocs=2) and the limit will no more be reached.

Ref: 268107.1