src/emuvim/dcemulator/resourcemodel/__init__.py

   1 """
   2 Base classes needed for resource models support.
   3 """
   4
   5 import logging
   6 LOG = logging.getLogger("resourcemodel")
   7 LOG.setLevel(logging.DEBUG)
   8
   9
  10 class ResourceModelRegistrar(object):
  11
  12     def __init__(self, dc_emulation_max_cpu):
  13         self.e_cpu = dc_emulation_max_cpu
  14         # pointer to all resource models assigned to DCs
  15         self._resource_models = dict()
  16         LOG.info("Resource model registrar created with dc_emulation_max_cpu=%r" % dc_emulation_max_cpu)
  17
  18     def register(self, dc, rm):
  19         if dc in self._resource_models:
  20             raise Exception("There is already an resource model assigned to this DC.")
  21         self._resource_models[dc] = rm
  22         rm.registrar = self
  23         LOG.info("Registrar: Added resource model: %r" % rm)
  24
  25     @property
  26     def num_models(self):
  27         return len(self._resource_models)
  28
  29     @property
  30     def resource_models(self):
  31         return list(self._resource_models.itervalues())
  32
  33
  34 class ResourceFlavor(object):
  35     """
  36     Simple class that represents resource flavors (c.f. OpenStack).
  37     Can contain arbitrary metrics.
  38     """
  39     def __init__(self, name, metrics):
  40         self.name = name
  41         self._metrics = metrics
  42         LOG.debug("Create flavor %r with metrics: %r" % (name, metrics))
  43
  44     def get(self, metric_key):
  45         return self._metrics.get(metric_key)
  46
  47
  48 class BaseResourceModel(object):
  49     """
  50     Base class for a resource limitation model.
  51     Has to be extended by a real resource model implementtion.
  52     """
  53
  54     def __init__(self):
  55         self._flavors=dict()
  56         self._initDefaultFlavors()
  57         self.registrar = None  # pointer to registrar
  58         LOG.info("Resource model %r initialized" % self)
  59
  60     def __repr__(self):
  61         return self.__class__.__name__
  62
  63     def _initDefaultFlavors(self):
  64         # initialize some default flavours (inspired by OpenStack)
  65         self.addFlavour(ResourceFlavor(
  66             "tiny",  {"compute": 1, "memory": 32, "disk": 1}))
  67         self.addFlavour(ResourceFlavor(
  68             "small",  {"compute": 4, "memory": 128, "disk": 20}))
  69         self.addFlavour(ResourceFlavor(
  70             "medium",  {"compute": 8, "memory": 256, "disk": 40}))
  71         self.addFlavour(ResourceFlavor(
  72             "large",  {"compute": 16, "memory": 512, "disk": 80}))
  73         self.addFlavour(ResourceFlavor(
  74             "xlarge",  {"compute": 32, "memory": 1024, "disk": 160}))
  75
  76     def addFlavour(self, fl):
  77         """
  78         Add a new flavor to the resource model.
  79         :param fl: flavor object
  80         :return: None
  81         """
  82         if fl.name in self._flavors:
  83             raise Exception("Flavor with name %r already exists!" % fl.name)
  84         self._flavors[fl.name] = fl
  85
  86     def allocate(self, name, flavor_name):
  87         """
  88         This method has to be overwritten by a real resource model.
  89         :param name: Name of the started compute instance.
  90         :param flavor_name:  Name of the flavor to be allocated.
  91         :return: 3-tuple: (CPU-fraction, Mem-limit, Disk-limit)
  92         """
  93         LOG.warning("Allocating in BaseResourceModel: %r with flavor: %r" % (name, flavor_name))
  94         return -1.0, -1.0, -1.0  # return invalid values to indicate that this RM is a dummy
  95
  96     def free(self, name):
  97         """
  98         This method has to be overwritten by a real resource model.
  99         :param name: Name of the compute instance that is stopped.
 100         :return: True/False
 101         """
 102         LOG.warning("Free in BaseResourceModel: %r" % name)
 103         return True