Source Code for Module Products.ZenModel.ValueChangeThreshold

 1  ############################################################################## 
 2  #  
 3  # Copyright (C) Zenoss, Inc. 2012, all rights reserved. 
 4  #  
 5  # This content is made available according to terms specified in 
 6  # License.zenoss under the directory where your Zenoss product is installed. 
 7  #  
 8  ############################################################################## 
 9   
10   
11  from Products.ZenModel.ThresholdInstance import RRDThresholdInstance 
12   
13  __doc__= """Threshold to track when a value changes. 
14  """ 
15   
16  from Globals import InitializeClass 
17  from ThresholdClass import ThresholdClass 
18  from ThresholdInstance import ThresholdContext 
19  from zenoss.protocols.protobufs.zep_pb2 import SEVERITY_INFO 
20  from Products.ZenEvents.ZenEventClasses import Status_Perf 
21   
22  import logging 
23  log = logging.getLogger('zen.MinMaxCheck') 
24   
25   
26  NaN = float('nan') 
27   
28 -class ValueChangeThreshold(ThresholdClass): 
29      """ 
30      Threshold that can watch changes in a value 
31      """ 
32       
33      eventClass = Status_Perf 
34      severity = SEVERITY_INFO 
35   
36 -    def createThresholdInstance(self, context): 
37          """Return the config used by the collector to process change thresholds 
38          """ 
39          mmt = ValueChangeThresholdInstance(self.id, 
40                                        ThresholdContext(context), 
41                                        self.dsnames, 
42                                        eventClass=self.eventClass, 
43                                        severity=self.severity) 
44          return mmt 
45   
46  InitializeClass(ValueChangeThreshold) 
47  ValueChangeThresholdClass = ValueChangeThreshold 
48   
49 -class ValueChangeThresholdInstance(RRDThresholdInstance): 
50      """ 
51      Threshold that emits an event when a value changes from its previous value. Does not send clear events. 
52      """ 
53   
54 -    def __init__(self, id, context, dpNames, eventClass, severity): 
55          RRDThresholdInstance.__init__(self, id, context, dpNames, eventClass, severity) 
56          self._lastValues = {} 
57   
58 -    def _checkImpl(self, dataPoint, value): 
59          dpKey = self._getDpKey(dataPoint) 
60          lastValue = self._lastValues.get(dpKey, None) 
61          if lastValue != value: 
62              self._lastValues[dpKey] = value 
63              event = dict( 
64                  device=self.context().deviceName, 
65                  summary="Value changed from %s to %s" % (lastValue, value), 
66                  eventKey=self.id, 
67                  eventClass=self.eventClass, 
68                  component=self.context().componentName, 
69                  current=value, 
70                  previous=lastValue, 
71                  severity=self.severity) 
72              return (event,) 
73          return tuple() 
74   
75 -    def _getDpKey(self, dp): 
76          return ':'.join(self.context().key()) + ':' + dp 
77   
78   
79  from twisted.spread import pb 
80  pb.setUnjellyableForClass(ValueChangeThresholdInstance, ValueChangeThresholdInstance) 
81