APEL was failing on ngsce-test with the following error.
java.io.FileNotFoundException: /var/spool/pbs/server_priv/accounting/20090522 (Too many open files)
The solution was to type:
ulimit -n 10240
I've added this to the /opt/glite/bin/apel-pbs-log-parser script.
A fix is in test, so a new version of APEL will fix it.
see GGUS ticket