contrail-database-nodemgr EXITED with traceback while calculating cpu/memory utilization of a analytics process

Build:R3.02 52 Kilo Ubuntu14.04

Logs saved at :http://10.204.216.50/Docs/bugs/<bug-id>

1.Had 3 database node - 'nodei27', 'nodei28' , 'nodei35'

In all the 3 nodes , contrail-database-nodemgr exited with the below traceback.
From the code in /usr/lib/python2.7/dist-packages/nodemgr/common/event_manager.py, looks like it tries to calculate the cpu/memory utilization of a list of analytics processes.

During this calculation , if one of them dies, contrail-database-nodemgr also dies.

In this setup,cassandra died due to
https://bugs.launchpad.net/juniperopenstack/+bug/1596803

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/gevent/greenlet.py", line 327, in run
    result = self._run(*self.args, **self.kwargs)
  File "/usr/lib/python2.7/dist-packages/nodemgr/database_nodemgr/database_event_manager.py", line 343, in runforever
    prev_current_time = self.event_tick_60(prev_current_time)
  File "/usr/lib/python2.7/dist-packages/nodemgr/common/event_manager.py", line 511, in event_tick_60
    process_mem_cpu_usage = self.get_all_processes_mem_cpu_usage()
  File "/usr/lib/python2.7/dist-packages/nodemgr/common/event_manager.py", line 396, in get_all_processes_mem_cpu_usage
    process_mem_cpu = mem_cpu_usage_data.get_process_mem_cpu_info()
  File "/usr/lib/python2.7/dist-packages/nodemgr/common/cpuinfo.py", line 86, in get_process_mem_cpu_info
    process_mem_cpu.cpu_share = self._process.get_cpu_percent(interval=0.1)/psutil.NUM_CPUS
  File "/usr/lib/python2.7/dist-packages/psutil/__init__.py", line 709, in get_cpu_percent
    pt2 = self._platform_impl.get_cpu_times()
  File "/usr/lib/python2.7/dist-packages/psutil/_pslinux.py", line 470, in wrapper
    raise NoSuchProcess(self.pid, self._process_name)
NoSuchProcess: process no longer exists (pid=3876)
<Greenlet at 0x7ffbc3e39870: <bound method DatabaseEventManager.runforever of <nodemgr.database_nodemgr.database_event_manager.DatabaseEventManager object at 0x7ffbc40f0e50>>> failed with NoSuchProcess