nm_mom.py

   1 #!/usr/bin/python
   2 #
   3 # Restarts NM if NM does not respond to periodic probes.
   4 #
   5 # Faiyaz Ahmed <faiyaza@cs.princeton.edu>
   6 # Copyright (C) 2006 The Trustees of Princeton University
   7 #
   8 # $Id: nm_mom.py,v 1.2 2006/08/17 20:12:09 faiyaza Exp $
   9 #
  10
  11 import syslog
  12 import os
  13 import sys
  14 import time
  15
  16 import socket
  17 import xmlrpclib
  18 import bwlimit
  19
  20 from sets import Set
  21
  22 # Utility functions
  23 from pl_mom import *
  24
  25
  26 def restartNM():
  27         try:
  28                 pid = os.fork()
  29                 if pid == 0:
  30                         bwlimit.run("/etc/init.d/pl_nm stop")
  31                         time.sleep(10)
  32                         try:
  33                                 nmpid = bwlimit.run("/bin/ps -e -o pid,cmd | grep nm.py")[0].split(" ")[0]
  34                                 os.kill(int(nmpid), 9)
  35                                 time.sleep(3)
  36                                 print "NM  %s forcefully killed." %nmpid
  37                         except:
  38                                 print "NM %s killed." %nmpid
  39                         bwlimit.run("/etc/init.d/pl_nm restart")
  40                         print "NM restarted."
  41                         os._exit(0)
  42                 else:
  43                         os.waitpid(pid,0)
  44         except Exception, err:
  45                 print "Warning: Exception received while restarting NM:  %s" % err
  46
  47
  48 def main():
  49         syslog.openlog("nm_mom")
  50         sys.stdout = sys.stderr = Logger()
  51
  52         nm = NM()
  53         last_maxrate = 0
  54         try:
  55                 # Query something.  If it doesnt come back...
  56                 vals = nm.query("pl_netflow", [('nm_net_max_rate', last_maxrate)])
  57
  58         except Exception, err:
  59                 print "Warning: Exception received while querying NM:", err
  60                 restartNM()
  61
  62 if __name__ == '__main__':
  63     main()