"Too many open files" Exceptions may be thrown from various non-deterministic places in the code:

java.io.FileNotFoundException: /opt/bea/weblogic_10.3.1.0/user_projects/domains/base_domain/edit.lok (Too many open files)
at java.io.FileOutputStream.open(Native Method)
at java.io.FileOutputStream.<init>(FileOutputStream.java:179)
at java.io.FileOutputStream.<init>(FileOutputStream.java:131)
at weblogic.management.provider.internal.EditLockManager.persistLock(EditLockManager.java:493)
at weblogic.management.provider.internal.EditLockManager.getEditLock(EditLockManager.java:244)
at weblogic.management.provider.internal.EditAccessImpl.acquireLock(EditAccessImpl.java:257)
at weblogic.management.provider.internal.EditAccessImpl.startEdit(EditAccessImpl.java:288)

Once source of excessive file handles can be rapid checking of the last modified time of the JSPs, configured by:

    <context-param>
        <param-name>com.icesoft.faces.reloadInterval</param-name>
        <param-value>500</param-value>
    </context-param>

The default is to check for modification every two seconds. With a large number of connected users, this check can exhaust the file handle limit before the file handles are automatically released.