Symptom:
ec.log is not updating.

ec_daemon.log shows:
Mon Feb 2 13:15:46 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 13:15:46 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 13:15:47 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 13:16:59 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 13:17:00 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 13:17:03 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 14:28:37 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 16:08:35 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Mon Feb 2 16:08:37 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
<snip>
Fri Feb 20 22:05:02 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Fri Feb 20 22:12:42 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Fri Feb 20 23:00:07 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Fri Feb 20 23:00:18 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 01:09:08 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 01:09:08 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 01:09:09 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 04:05:35 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 04:05:35 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log
Sat Feb 21 04:05:35 2015 GMT writeToLog open for writing failure Errno: 13 /opt/log/ec/ec.log

Conditions:
- CWMS 2.5(MR1)
- Multi-Data center deployment