Added state information per slice. Slices are now killed after consuming more
authorFaiyaz Ahmed <faiyaza@cs.princeton.edu>
Mon, 17 Jul 2006 19:31:27 +0000 (19:31 +0000)
committerFaiyaz Ahmed <faiyaza@cs.princeton.edu>
Mon, 17 Jul 2006 19:31:27 +0000 (19:31 +0000)
memory than the threshold more than twice.  Also fixed the slice restart issue where
slices would be restarted and repeated restart emails would be sent.

swapmon.py

index 3f6304e..a29a59e 100755 (executable)
@@ -7,9 +7,10 @@
 #
 # Mark Huang <mlhuang@cs.princeton.edu>
 # Andy Bavier <acb@cs.princeton.edu>
+# Faiyaz Ahmed <faiyaza@cs.princeton.edu>
 # Copyright (C) 2004-2006 The Trustees of Princeton University
 #
-# $Id: swapmon.py,v 1.4 2006/05/02 17:23:14 mlhuang Exp $
+# $Id: swapmon.py,v 1.5 2006/05/09 03:23:57 mlhuang Exp $
 #
 
 import syslog
@@ -44,11 +45,20 @@ period = 30
 change_thresh = 5
 
 # Swap utilization at which the largest consumer of physical memory is reset
-reset_thresh = 85
+reset_thresh = 75
 
 # Swap utilization at which the machine is rebooted
 reboot_thresh = 95
 
+# Time to wait before checking slice again after reset
+reset_timeout = 10
+
+# Number of strikes before killing (strike, strike, kill)
+kill_thresh = 2
+
+# Time to wait before removing slice from kill queue 
+kill_timeout = 30 
+
 # Minimum physical memory utilization to be considered the largest consumer
 min_thresh = 10
 
@@ -108,6 +118,117 @@ behavior.
 %(date)s %(hostname)s alarm %(slice)s
 """.lstrip()
 
+# Message sent after a slice has been killed
+kill_subject = "pl_mom killed slice %(slice)s on %(hostname)s"
+kill_body = \
+"""
+Sometime before %(date)s, swap space was
+nearly exhausted on %(hostname)s.
+
+Slice %(slice)s was killed since it was the largest consumer of
+physical memory at %(rss)s (%(percent)4.1f%%) after repeated restarts.
+
+Please reply to this message explaining the nature of your experiment,
+and what you are doing to address the problem.
+
+%(slice)s processes prior to reset:
+
+%(table)s
+
+%(date)s %(hostname)s reset %(slice)s
+""".lstrip()
+
+
+
+class Reset:
+       """
+       Keeps track of state information for resets and kills
+
+       resettimeleft - timeout before checking for next reset
+       resetcount - number of strikes 
+       killtimeleft - time out before removing from kill queue 
+       """
+
+       def __init__(self,name):
+               self.name = name
+               self.resettimeleft = reset_timeout
+               self.resetcount = 0 
+               self.killtimeleft = kill_timeout
+
+       def __repr__(self):
+               return self.name
+       
+       def update(self):
+               # Count down for next check of reset slice.
+                       if self.resettimeleft > 0:
+                        self.resettimeleft -= 1
+                        if debug and verbose:
+                                       print "%s has %s seconds to die and has been reset %s times" \
+                                       %(self.name, self.resettimeleft, self.resetcount)
+                                       print "%s has %s seconds in probation" \
+                                       %(self.name, self.killtimeleft)
+               if self.killtimeleft > 0:
+                       # Count down kill probation timer (killtimeleft)
+                       self.killtimeleft -= 1
+               else:
+                       # Once out of probation period (killtimeleft), remove strike
+                       self.resetcount = 0
+
+
+       # Check to see if a slice needs to be killed.  If it has rules more than kill_thresh in 
+       # the probation period (kill_timeout) send an email, kill the slice.
+       def checkkill(self,params):
+               if self.killtimeleft > 0 and self.resetcount >= kill_thresh:
+                       if debug:
+                                print kill_subject % params
+                                print kill_body % params
+                       try:
+                               pid = os.fork()
+                               if pid == 0:
+                                       print "Slice %s is being killed." % self.name   
+                                       vserver = VServer(self.name)
+                                       vserver.stop()
+                               else:
+                                       os.waitpid(pid,0)
+                       except Exception, err:
+                                print "Warning: Exception received while killing slice %s: %s" % self.name, err
+                       slicemail(self.name, kill_subject % params, kill_body % params)
+                       return True
+               return False 
+
+       # Reset slice after checking to see if slice is out of timeout.
+       # Increment resetcount, check to see if larger than kill_thresh.
+       def reset(self, params):
+               # If its the first reset or if its been reset before
+               # and we are out of the reset timeout.
+               if self.resetcount == 0 or self.resettimeleft == 0:
+                       # Do we need to kill this slice?  Check history first.
+                       if self.checkkill(params):
+                               return
+                       # Update counters
+                       self.resetcount += 1
+                       self.killtimeleft = kill_timeout
+                       self.resettimeleft = reset_timeout
+                       if debug:
+                               print reset_subject % params
+                               print reset_body % params
+                       try:
+                               pid = os.fork()
+                               if pid == 0:
+                                       print "Resetting slice " + self.name 
+                                       vserver = VServer(self.name)
+                                       vserver.stop()
+                                       vserver.start(wait = False)
+                                       os._exit(0)
+                               else:
+                                       os.waitpid(pid, 0)
+                       except Exception, err:
+                               print "Warning: Exception received while resetting slice %s:" \
+                                       % self.name, err
+                       slicemail(self.name, reset_subject % params, reset_body % params)
+
+
+
 def usage():
     print """
 Usage: %s [OPTIONS]...
@@ -349,7 +470,7 @@ def main():
         (version, slices) = pickle.load(f)
         f.close()
         # Check version of data file
-        if version != "$Id: swapmon.py,v 1.4 2006/05/02 17:23:14 mlhuang Exp $":
+        if version != "$Id: swapmon.py,v 1.5 2006/05/09 03:23:57 mlhuang Exp $":
             print "Not using old version '%s' data file %s" % (version, datafile)
             raise Exception
 
@@ -366,7 +487,7 @@ def main():
         # Delete data file
         os.unlink(datafile)
     except Exception:
-        version = "$Id: swapmon.py,v 1.4 2006/05/02 17:23:14 mlhuang Exp $"
+        version = "$Id: swapmon.py,v 1.5 2006/05/09 03:23:57 mlhuang Exp $"
         slices = {}
 
     # Query process table every 30 seconds, or when a large change in
@@ -378,11 +499,18 @@ def main():
     # System slices that we have warned but could not reset
     warned = []
 
+    # Slices that were reset
+    resetlist = {}
+
     while True:
         used = swap_used()
+
+       for resetslice in resetlist.keys():
+               resetlist[resetslice].update()
+       
         if last_used is None:
             last_used = used
-        if verbose:
+       if verbose:
             print "%d%% swap consumed" % used
 
         if used >= reboot_thresh:
@@ -404,9 +532,10 @@ def main():
             slicelist.sort(lambda a, b: b['rss'] - a['rss'])
             for slice in slicelist:
                 percent = 100. * slice['rss'] / total_rss
+
                 if percent < min_thresh:
                     continue
-
+               
                 print "%d%% swap consumed, slice %s is using %s (%d%%) of memory" % \
                       (used,
                        slice['name'],
@@ -444,25 +573,10 @@ def main():
                             print "Warning slice " + slice['name']
                             slicemail(slice['name'], alarm_subject % params, alarm_body % params)
                 else:
-                    # Otherwise, reset
-                    if debug:
-                        print reset_subject % params
-                        print reset_body % params
-                    else:
-                        try:
-                            pid = os.fork()
-                            if pid == 0:
-                                print "Resetting slice " + slice['name']
-                                vserver = VServer(slice['name'])
-                                vserver.stop()
-                                vserver.start(wait = False)
-                                os._exit(0)
-                            else:
-                                os.waitpid(pid, 0)
-                        except Exception, err:
-                            print "Warning: Exception received while resetting slice %s:" % slice['name'], err
-                        slicemail(slice['name'], reset_subject % params, reset_body % params)
-                    break
+                       # Reset slice
+                       if not resetlist.has_key(slice['name']):
+                               resetlist[slice['name']] = Reset(slice['name'])
+                        resetlist[slice['name']].reset(params)
 
         elif timer <= 0 or used >= (last_used + change_thresh):
             if used >= (last_used + change_thresh):