Source Code for Module ZenRRD.RRDUtil

 1  ########################################################################### 
 2  # 
 3  # This program is part of Zenoss Core, an open source monitoring platform. 
 4  # Copyright (C) 2007, Zenoss Inc. 
 5  # 
 6  # This program is free software; you can redistribute it and/or modify it 
 7  # under the terms of the GNU General Public License version 2 as published by 
 8  # the Free Software Foundation. 
 9  # 
10  # For complete information please visit: http://www.zenoss.com/oss/ 
11  # 
12  ########################################################################### 
13   
14  import logging 
15  log = logging.getLogger("zen.RRDUtil") 
16   
17  from Products.ZenModel.PerformanceConf import performancePath 
18   
19 -def _checkUndefined(x): 
20      if x is None or x == '' or x == -1 or x == '-1': 
21          return 'U' 
22      return x 
23   
24 -class RRDUtil: 
25 -    def __init__(self, defaultRrdCreateCommand, defaultCycleTime): 
26          self.defaultRrdCreateCommand = defaultRrdCreateCommand 
27          self.defaultCycleTime = defaultCycleTime 
28   
29 -    def save(self, path, value, rrdType, rrdCommand=None, cycleTime=None, 
30               min='U', max='U'): 
31          import rrdtool, os 
32   
33          if value is None: return None 
34   
35          if cycleTime is None: 
36              cycleTime = self.defaultCycleTime 
37   
38          filename = performancePath(path) + '.rrd' 
39          if not rrdCommand: 
40              rrdCommand = self.defaultRrdCreateCommand 
41          if not os.path.exists(filename): 
42              log.debug("create new rrd %s", filename) 
43              dirname = os.path.dirname(filename) 
44              if not os.path.exists(dirname): 
45                  os.makedirs(dirname, 0750) 
46   
47              min, max = map(_checkUndefined, (min, max)) 
48              dataSource = 'DS:%s:%s:%d:%s:%s' % ('ds0', rrdType, 
49                                                  3*cycleTime, min, max) 
50              rrdtool.create(filename, 
51                             "--step",  str(cycleTime), 
52                             str(dataSource), *rrdCommand.split()) 
53           
54          if rrdType in ('COUNTER', 'DERIVE'): 
55              try: 
56                  value = long(value) 
57              except (TypeError, ValueError): 
58                  return None 
59          try: 
60              rrdtool.update(filename, 'N:%s' % value) 
61              log.debug('%s: %r', filename, value) 
62          except rrdtool.error, err: 
63              # may get update errors when updating too quickly 
64              log.error('rrd error %s %s', err, path) 
65   
66          if rrdType in ('COUNTER', 'DERIVE'): 
67              startStop, names, values = \ 
68                         rrdtool.fetch(filename, 'AVERAGE', 
69                                       '-s', 'now-%d' % (cycleTime*2), 
70                                       '-e', 'now') 
71              value = values[0][0] 
72          return value 
73