Cleaning up RM template

[nepi.git] / src / nepi / execution / resource.py

diff --git a/src/nepi/execution/resource.py b/src/nepi/execution/resource.py
index b4994e0..16b434f 100644 (file)
--- a/src/nepi/execution/resource.py
+++ b/src/nepi/execution/resource.py
@@ -28,10 +28,9 @@ import logging
 import os
 import pkgutil
 import sys
 import os
 import pkgutil
 import sys

+import threading

 import weakref
 
 import weakref
 

-reschedule_delay = "1s"
-

 class ResourceAction:
     """ Action that a user can order to a Resource Manager
    
 class ResourceAction:
     """ Action that a user can order to a Resource Manager
    


@@ -46,74 +45,104 @@ class ResourceState:
     """
     NEW = 0
     DISCOVERED = 1
     """
     NEW = 0
     DISCOVERED = 1

-    PROVISIONED = 2
-    READY = 3
-    STARTED = 4
-    STOPPED = 5
-    FINISHED = 6
+    RESERVED = 2
+    PROVISIONED = 3
+    READY = 4
+    STARTED = 5
+    STOPPED = 6

     FAILED = 7
     RELEASED = 8
 
 ResourceState2str = dict({
     ResourceState.NEW : "NEW",
     ResourceState.DISCOVERED : "DISCOVERED",
     FAILED = 7
     RELEASED = 8
 
 ResourceState2str = dict({
     ResourceState.NEW : "NEW",
     ResourceState.DISCOVERED : "DISCOVERED",

+    ResourceState.RESERVED : "RESERVED",

     ResourceState.PROVISIONED : "PROVISIONED",
     ResourceState.READY : "READY",
     ResourceState.STARTED : "STARTED",
     ResourceState.STOPPED : "STOPPED",
     ResourceState.PROVISIONED : "PROVISIONED",
     ResourceState.READY : "READY",
     ResourceState.STARTED : "STARTED",
     ResourceState.STOPPED : "STOPPED",

-    ResourceState.FINISHED : "FINISHED",

     ResourceState.FAILED : "FAILED",
     ResourceState.RELEASED : "RELEASED",
     })
 
 def clsinit(cls):
     """ Initializes template information (i.e. attributes and traces)
     ResourceState.FAILED : "FAILED",
     ResourceState.RELEASED : "RELEASED",
     })
 
 def clsinit(cls):
     """ Initializes template information (i.e. attributes and traces)

-    for the ResourceManager class
-    """
+    on classes derived from the ResourceManager class.
+
+    It is used as a decorator in the class declaration as follows:
+
+        @clsinit
+        class MyResourceManager(ResourceManager):
+        
+            ...
+
+     """
+

     cls._clsinit()
     return cls
 
 def clsinit_copy(cls):
     """ Initializes template information (i.e. attributes and traces)
     cls._clsinit()
     return cls
 
 def clsinit_copy(cls):
     """ Initializes template information (i.e. attributes and traces)

-    for the ResourceManager class, inheriting attributes and traces
-    from the parent class
+    on classes direved from the ResourceManager class.
+    It differs from the clsinit method in that it forces inheritance
+    of attributes and traces from the parent class.
+
+    It is used as a decorator in the class declaration as follows:
+
+        @clsinit
+        class MyResourceManager(ResourceManager):
+        
+            ...
+
+
+    clsinit_copy should be prefered to clsinit when creating new
+    ResourceManager child classes.
+

     """
     """

+    

     cls._clsinit_copy()
     return cls
 
 def failtrap(func):
     cls._clsinit_copy()
     return cls
 
 def failtrap(func):

+    """ Decorator function for instance methods that should set the 
+    RM state to FAILED when an error is raised. The methods that must be
+    decorated are: discover, reserved, provision, deploy, start, stop.
+
+    """

     def wrapped(self, *args, **kwargs):
         try:
             return func(self, *args, **kwargs)
         except:
     def wrapped(self, *args, **kwargs):
         try:
             return func(self, *args, **kwargs)
         except:

+            self.fail()
+            

             import traceback
             err = traceback.format_exc()
             import traceback
             err = traceback.format_exc()

-            self.error(err)
-            self.debug("SETTING guid %d to state FAILED" % self.guid)
-            self.fail()
+            logger = Logger(self._rtype)
+            logger.error(err)
+            logger.error("SETTING guid %d to state FAILED" % self.guid)

             raise
     
     return wrapped
 
             raise
     
     return wrapped
 

-# Decorator to invoke class initialization method

 @clsinit
 class ResourceManager(Logger):
     """ Base clase for all ResourceManagers. 
     
     A ResourceManger is specific to a resource type (e.g. Node, 
 @clsinit
 class ResourceManager(Logger):
     """ Base clase for all ResourceManagers. 
     
     A ResourceManger is specific to a resource type (e.g. Node, 

-    Switch, Application, etc) on a specific backend (e.g. PlanetLab, 
+    Switch, Application, etc) on a specific platform (e.g. PlanetLab, 

     OMF, etc).
 
     The ResourceManager instances are responsible for interacting with
     and controlling concrete (physical or virtual) resources in the 
     OMF, etc).
 
     The ResourceManager instances are responsible for interacting with
     and controlling concrete (physical or virtual) resources in the 

-    experimental backends.
+    experimental platforms.

     
     """
     _rtype = "Resource"
     _attributes = None
     _traces = None
     _help = None
     
     """
     _rtype = "Resource"
     _attributes = None
     _traces = None
     _help = None

-    _backend = None
+    _platform = None
+    _reschedule_delay = "0.5s"

 
     @classmethod
     def _register_attribute(cls, attr):
 
     @classmethod
     def _register_attribute(cls, attr):


@@ -121,6 +150,7 @@ class ResourceManager(Logger):
         resource attribute
 
         """
         resource attribute
 
         """

+        

         cls._attributes[attr.name] = attr
 
     @classmethod
         cls._attributes[attr.name] = attr
 
     @classmethod


@@ -129,6 +159,7 @@ class ResourceManager(Logger):
         resource attribute
 
         """
         resource attribute
 
         """

+        

         del cls._attributes[name]
 
     @classmethod
         del cls._attributes[name]
 
     @classmethod


@@ -137,6 +168,7 @@ class ResourceManager(Logger):
         resource trace
 
         """
         resource trace
 
         """

+        

         cls._traces[trace.name] = trace
 
     @classmethod
         cls._traces[trace.name] = trace
 
     @classmethod


@@ -145,40 +177,60 @@ class ResourceManager(Logger):
         resource trace
 
         """
         resource trace
 
         """

+        

         del cls._traces[name]
 
     @classmethod
     def _register_attributes(cls):
         """ Resource subclasses will invoke this method to register
         del cls._traces[name]
 
     @classmethod
     def _register_attributes(cls):
         """ Resource subclasses will invoke this method to register

-        resource attributes
+        resource attributes.
+
+        This method should be overriden in the RMs that define
+        attributes.

 
         """
 
         """

-        critical = Attribute("critical", "Defines whether the resource is critical. "
-                " A failure on a critical resource will interrupt the experiment. ",
+        critical = Attribute("critical", 
+                "Defines whether the resource is critical. "
+                "A failure on a critical resource will interrupt "
+                "the experiment. ",

                 type = Types.Bool,
                 default = True,
                 type = Types.Bool,
                 default = True,

-                flags = Flags.ExecReadOnly)
+                flags = Flags.Design)
+        hard_release = Attribute("hardRelease", 
+                "Forces removal of all result files and directories associated "
+                "to the RM upon resource release. After release the RM will "
+                "be removed from the EC and the results will not longer be "
+                "accessible",
+                type = Types.Bool,
+                default = False,
+                flags = Flags.Design)

 
         cls._register_attribute(critical)
 
         cls._register_attribute(critical)

+        cls._register_attribute(hard_release)

         
     @classmethod
     def _register_traces(cls):
         """ Resource subclasses will invoke this method to register
         resource traces
 
         
     @classmethod
     def _register_traces(cls):
         """ Resource subclasses will invoke this method to register
         resource traces
 

+        This method should be overriden in the RMs that define traces.
+        

         """
         """

+        

         pass
 
     @classmethod
     def _clsinit(cls):
         pass
 
     @classmethod
     def _clsinit(cls):

-        """ ResourceManager child classes have different attributes and traces.
-        Since the templates that hold the information of attributes and traces
-        are 'class attribute' dictionaries, initially they all point to the 
-        parent class ResourceManager instances of those dictionaries. 
-        In order to make these templates independent from the parent's one,
-        it is necessary re-initialize the corresponding dictionaries. 
-        This is the objective of the _clsinit method
+        """ ResourceManager classes have different attributes and traces.
+        Attribute and traces are stored in 'class attribute' dictionaries.
+        When a new ResourceManager class is created, the _clsinit method is 
+        called to create a new instance of those dictionaries and initialize 
+        them.
+        
+        The _clsinit method is called by the clsinit decorator method.
+        

         """
         """

+        

         # static template for resource attributes
         cls._attributes = dict()
         cls._register_attributes()
         # static template for resource attributes
         cls._attributes = dict()
         cls._register_attributes()


@@ -189,8 +241,12 @@ class ResourceManager(Logger):
 
     @classmethod
     def _clsinit_copy(cls):
 
     @classmethod
     def _clsinit_copy(cls):

-        """ Same as _clsinit, except that it also inherits all attributes and traces
-        from the parent class.
+        """ Same as _clsinit, except that after creating new instances of the
+        dictionaries it copies all the attributes and traces from the parent 
+        class.
+        
+        The _clsinit_copy method is called by the clsinit_copy decorator method.
+        

         """
         # static template for resource attributes
         cls._attributes = copy.deepcopy(cls._attributes)
         """
         # static template for resource attributes
         cls._attributes = copy.deepcopy(cls._attributes)


@@ -201,7 +257,7 @@ class ResourceManager(Logger):
         cls._register_traces()
 
     @classmethod
         cls._register_traces()
 
     @classmethod

-    def rtype(cls):
+    def get_rtype(cls):

         """ Returns the type of the Resource Manager
 
         """
         """ Returns the type of the Resource Manager
 
         """


@@ -214,6 +270,13 @@ class ResourceManager(Logger):
         """
         return copy.deepcopy(cls._attributes.values())
 
         """
         return copy.deepcopy(cls._attributes.values())
 

+    @classmethod
+    def get_attribute(cls, name):
+        """ Returns a copy of the attribute with name 'name'
+
+        """
+        return copy.deepcopy(cls._attributes[name])
+

     @classmethod
     def get_traces(cls):
         """ Returns a copy of the traces
     @classmethod
     def get_traces(cls):
         """ Returns a copy of the traces


@@ -229,15 +292,41 @@ class ResourceManager(Logger):
         return cls._help
 
     @classmethod
         return cls._help
 
     @classmethod

-    def get_backend(cls):
-        """ Returns the identified of the backend (i.e. testbed, environment)
+    def get_platform(cls):
+        """ Returns the identified of the platform (i.e. testbed type)

         for the Resource
 
         """
         for the Resource
 
         """

-        return cls._backend
+        return cls._platform
+
+    @classmethod
+    def get_global(cls, name):
+        """ Returns the value of a global attribute
+            Global attribute meaning an attribute for 
+            all the resources from a rtype
+
+        :param name: Name of the attribute
+        :type name: str
+        :rtype: str
+        """
+        global_attr = cls._attributes[name]
+        return global_attr.value
+
+    @classmethod
+    def set_global(cls, name, value):
+        """ Set value for a global attribute
+
+        :param name: Name of the attribute
+        :type name: str
+        :param name: Value of the attribute
+        :type name: str
+        """
+        global_attr = cls._attributes[name]
+        global_attr.value = value
+        return value

 
     def __init__(self, ec, guid):
 
     def __init__(self, ec, guid):

-        super(ResourceManager, self).__init__(self.rtype())
+        super(ResourceManager, self).__init__(self.get_rtype())

         
         self._guid = guid
         self._ec = weakref.ref(ec)
         
         self._guid = guid
         self._ec = weakref.ref(ec)


@@ -257,14 +346,19 @@ class ResourceManager(Logger):
         self._start_time = None
         self._stop_time = None
         self._discover_time = None
         self._start_time = None
         self._stop_time = None
         self._discover_time = None

+        self._reserved_time = None

         self._provision_time = None
         self._ready_time = None
         self._release_time = None
         self._provision_time = None
         self._ready_time = None
         self._release_time = None

-        self._finish_time = None

         self._failed_time = None
 
         self._state = ResourceState.NEW
 
         self._failed_time = None
 
         self._state = ResourceState.NEW
 

+        # instance lock to synchronize exclusive state change methods (such
+        # as deploy and release methods), in order to prevent them from being 
+        # executed at the same time and corrupt internal resource state
+        self._release_lock = threading.Lock()
+

     @property
     def guid(self):
         """ Returns the global unique identifier of the RM """
     @property
     def guid(self):
         """ Returns the global unique identifier of the RM """


@@ -272,60 +366,62 @@ class ResourceManager(Logger):
 
     @property
     def ec(self):
 
     @property
     def ec(self):

-        """ Returns the Experiment Controller """
+        """ Returns the Experiment Controller of the RM """

         return self._ec()
 
     @property
     def connections(self):
         return self._ec()
 
     @property
     def connections(self):

-        """ Returns the set of guids of connected RMs"""
+        """ Returns the set of guids of connected RMs """

         return self._connections
 
     @property
     def conditions(self):
         """ Returns the conditions to which the RM is subjected to.
         
         return self._connections
 
     @property
     def conditions(self):
         """ Returns the conditions to which the RM is subjected to.
         

-        The object returned by this method is a dictionary indexed by
-        ResourceAction."""
+        This method returns a dictionary of conditions lists indexed by
+        a ResourceAction.
+        
+        """

         return self._conditions
 
     @property
     def start_time(self):
         return self._conditions
 
     @property
     def start_time(self):

-        """ Returns the start time of the RM as a timestamp"""
+        """ Returns the start time of the RM as a timestamp """

         return self._start_time
 
     @property
     def stop_time(self):
         return self._start_time
 
     @property
     def stop_time(self):

-        """ Returns the stop time of the RM as a timestamp"""
+        """ Returns the stop time of the RM as a timestamp """

         return self._stop_time
 
     @property
     def discover_time(self):
         return self._stop_time
 
     @property
     def discover_time(self):

-        """ Returns the time discovering was finished for the RM as a timestamp"""
+        """ Returns the discover time of the RM as a timestamp """

         return self._discover_time
 
         return self._discover_time
 

+    @property
+    def reserved_time(self):
+        """ Returns the resreved time of the RM as a timestamp """
+        return self._reserved_time
+

     @property
     def provision_time(self):
     @property
     def provision_time(self):

-        """ Returns the time provisioning was finished for the RM as a timestamp"""
+        """ Returns the provision time of the RM as a timestamp """

         return self._provision_time
 
     @property
     def ready_time(self):
         return self._provision_time
 
     @property
     def ready_time(self):

-        """ Returns the time deployment was finished for the RM as a timestamp"""
+        """ Returns the deployment time of the RM as a timestamp """

         return self._ready_time
 
     @property
     def release_time(self):
         return self._ready_time
 
     @property
     def release_time(self):

-        """ Returns the release time of the RM as a timestamp"""
+        """ Returns the release time of the RM as a timestamp """

         return self._release_time
 
         return self._release_time
 

-    @property
-    def finish_time(self):
-        """ Returns the finalization time of the RM as a timestamp"""
-        return self._finish_time
-

     @property
     def failed_time(self):
     @property
     def failed_time(self):

-        """ Returns the time failure occured for the RM as a timestamp"""
+        """ Returns the time failure occured for the RM as a timestamp """

         return self._failed_time
 
     @property
         return self._failed_time
 
     @property


@@ -333,153 +429,185 @@ class ResourceManager(Logger):
         """ Get the current state of the RM """
         return self._state
 
         """ Get the current state of the RM """
         return self._state
 

+    @property
+    def reschedule_delay(self):
+        """ Returns default reschedule delay """
+        return self._reschedule_delay
+

     def log_message(self, msg):
         """ Returns the log message formatted with added information.
 
         :param msg: text message
         :type msg: str
         :rtype: str
     def log_message(self, msg):
         """ Returns the log message formatted with added information.
 
         :param msg: text message
         :type msg: str
         :rtype: str

+

         """
         """

-        return " %s guid: %d - %s " % (self._rtype, self.guid, msg)
+        return " %s guid %d - %s " % (self._rtype, self.guid, msg)

 
     def register_connection(self, guid):
         """ Registers a connection to the RM identified by guid
 
 
     def register_connection(self, guid):
         """ Registers a connection to the RM identified by guid
 

+        This method should not be overriden. Specific functionality
+        should be added in the do_connect method.
+

         :param guid: Global unique identified of the RM to connect to
         :type guid: int
         :param guid: Global unique identified of the RM to connect to
         :type guid: int

+

         """
         if self.valid_connection(guid):
         """
         if self.valid_connection(guid):

-            self.connect(guid)
+            self.do_connect(guid)

             self._connections.add(guid)
 
     def unregister_connection(self, guid):
         """ Removes a registered connection to the RM identified by guid
             self._connections.add(guid)
 
     def unregister_connection(self, guid):
         """ Removes a registered connection to the RM identified by guid

+        
+        This method should not be overriden. Specific functionality
+        should be added in the do_disconnect method.

 
         :param guid: Global unique identified of the RM to connect to
         :type guid: int
 
         :param guid: Global unique identified of the RM to connect to
         :type guid: int

+

         """
         if guid in self._connections:
         """
         if guid in self._connections:

-            self.disconnect(guid)
+            self.do_disconnect(guid)

             self._connections.remove(guid)
 
             self._connections.remove(guid)
 

+    @failtrap

     def discover(self):
         """ Performs resource discovery.
     def discover(self):
         """ Performs resource discovery.

-
+        

         This  method is responsible for selecting an individual resource
         matching user requirements.
         This  method is responsible for selecting an individual resource
         matching user requirements.

-        This method should be redefined when necessary in child classes.

 
 

-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_discover method.

 
         """
 
         """

-        self.set_discovered()
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_discover()
+
+    @failtrap
+    def reserve(self):
+        """ Performs resource reserve.
+        
+        This  method is responsible for reserving an individual resource
+        matching user requirements.
+
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_reserved method.

 
 

+        """
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_reserve()
+
+    @failtrap

     def provision(self):
         """ Performs resource provisioning.
 
         This  method is responsible for provisioning one resource.
         After this method has been successfully invoked, the resource
         should be accessible/controllable by the RM.
     def provision(self):
         """ Performs resource provisioning.
 
         This  method is responsible for provisioning one resource.
         After this method has been successfully invoked, the resource
         should be accessible/controllable by the RM.

-        This method should be redefined when necessary in child classes.

 
 

-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_provision method.

 
         """
 
         """

-        self.set_provisioned()
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_provision()

 
 

+    @failtrap

     def start(self):
     def start(self):

-        """ Starts the RM.
-        
-        There is no generic start behavior for all resources.
-        This method should be redefined when necessary in child classes.
+        """ Starts the RM (e.g. launch remote process).
+    
+        There is no standard start behavior. Some RMs will not need to perform
+        any actions upon start.

 
 

-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_start method.

 
         """
 
         """

+

         if not self.state in [ResourceState.READY, ResourceState.STOPPED]:
             self.error("Wrong state %s for start" % self.state)
             return
 
         if not self.state in [ResourceState.READY, ResourceState.STOPPED]:
             self.error("Wrong state %s for start" % self.state)
             return
 

-        self.set_started()
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_start()

 
 

+    @failtrap

     def stop(self):
         """ Interrupts the RM, stopping any tasks the RM was performing.
     def stop(self):
         """ Interrupts the RM, stopping any tasks the RM was performing.

-        
-        There is no generic stop behavior for all resources.
-        This method should be redefined when necessary in child classes.
-
-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.
-
+     
+        There is no standard stop behavior. Some RMs will not need to perform
+        any actions upon stop.
+    
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_stop method.
+      

         """
         if not self.state in [ResourceState.STARTED]:
             self.error("Wrong state %s for stop" % self.state)
             return
         
         """
         if not self.state in [ResourceState.STARTED]:
             self.error("Wrong state %s for stop" % self.state)
             return
         

-        self.set_stopped()
+        with self._release_lock:
+            self.do_stop()

 
 

+    @failtrap

     def deploy(self):
         """ Execute all steps required for the RM to reach the state READY.
 
     def deploy(self):
         """ Execute all steps required for the RM to reach the state READY.
 

-        This  method is responsible for deploying the resource (and invoking the
-        discover and provision methods).
-        This method should be redefined when necessary in child classes.
-
-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.
-
+        This method is responsible for deploying the resource (and invoking 
+        the discover and provision methods).
+ 
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_deploy method.
+       

         """
         if self.state > ResourceState.READY:
             self.error("Wrong state %s for deploy" % self.state)
             return
 
         """
         if self.state > ResourceState.READY:
             self.error("Wrong state %s for deploy" % self.state)
             return
 

-        self.debug("----- READY ---- ")
-        self.set_ready()
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_deploy()

 
     def release(self):
         """ Perform actions to free resources used by the RM.
 
     def release(self):
         """ Perform actions to free resources used by the RM.

-        
+  

         This  method is responsible for releasing resources that were
         used during the experiment by the RM.
         This  method is responsible for releasing resources that were
         used during the experiment by the RM.

-        This method should be redefined when necessary in child classes.
-
-        If overridden in child classes, this method should never
-        raise an error and it must ensure the RM is set to state RELEASED.
-
-        """
-        self.set_released()
-
-    def finish(self):
-        """ Sets the RM to state FINISHED. 
-        
-        The FINISHED state is different from STOPPED in that it should not be 
-        directly invoked by the user.
-        STOPPED indicates that the user interrupted the RM, FINISHED means
-        that the RM concluded normally the actions it was supposed to perform.
-        This method should be redefined when necessary in child classes.
-        
-        If overridden in child classes, make sure to use the failtrap 
-        decorator to ensure the RM state will be set to FAILED in the event 
-        of an exception.

 
 

+        This method should not be overriden directly. Specific functionality
+        should be added in the do_release method.
+      

         """
         """

+        with self._release_lock:
+            try:
+                self.do_release()
+            except:
+                self.set_released()
+
+                import traceback
+                err = traceback.format_exc()
+                msg = " %s guid %d ----- FAILED TO RELEASE ----- \n %s " % (
+                        self._rtype, self.guid, err)
+                logger = Logger(self._rtype)
+                logger.debug(msg)

 
 

-        self.set_finished()
- 

     def fail(self):
         """ Sets the RM to state FAILED.
 
     def fail(self):
         """ Sets the RM to state FAILED.
 

-        """
+        This method should not be overriden directly. Specific functionality
+        should be added in the do_fail method.

 
 

-        self.set_failed()
+        """
+        with self._release_lock:
+            if self._state != ResourceState.RELEASED:
+                self.do_fail()

 
     def set(self, name, value):
         """ Set the value of the attribute
 
     def set(self, name, value):
         """ Set the value of the attribute


@@ -491,6 +619,7 @@ class ResourceManager(Logger):
         """
         attr = self._attrs[name]
         attr.value = value
         """
         attr = self._attrs[name]
         attr.value = value

+        return value

 
     def get(self, name):
         """ Returns the value of the attribute
 
     def get(self, name):
         """ Returns the value of the attribute


@@ -500,8 +629,43 @@ class ResourceManager(Logger):
         :rtype: str
         """
         attr = self._attrs[name]
         :rtype: str
         """
         attr = self._attrs[name]

+
+        """
+        A.Q. Commenting due to performance impact
+        if attr.has_flag(Flags.Global):
+            self.warning( "Attribute %s is global. Use get_global instead." % name)
+        """
+            

         return attr.value
 
         return attr.value
 

+    def has_changed(self, name):
+        """ Returns the True is the value of the attribute
+            has been modified by the user.
+
+        :param name: Name of the attribute
+        :type name: str
+        :rtype: str
+        """
+        attr = self._attrs[name]
+        return attr.has_changed
+
+    def has_flag(self, name, flag):
+        """ Returns true if the attribute has the flag 'flag'
+
+        :param flag: Flag to be checked
+        :type flag: Flags
+        """
+        attr = self._attrs[name]
+        return attr.has_flag(flag)
+
+    def has_attribute(self, name):
+        """ Returns true if the RM has an attribute with name
+
+        :param name: name of the attribute
+        :type name: string
+        """
+        return name in self._attrs
+

     def enable_trace(self, name):
         """ Explicitly enable trace generation
 
     def enable_trace(self, name):
         """ Explicitly enable trace generation
 


@@ -617,6 +781,19 @@ class ResourceManager(Logger):
                 connected.append(rm)
         return connected
 
                 connected.append(rm)
         return connected
 

+    def is_rm_instance(self, rtype):
+        """ Returns True if the RM is instance of 'rtype'
+
+        :param rtype: Type of the RM we look for
+        :type rtype: str
+        :return: True|False
+        """
+        rclass = ResourceFactory.get_resource_type(rtype)
+        if isinstance(self, rclass):
+            return True
+        return False
+
+    @failtrap

     def _needs_reschedule(self, group, state, time):
         """ Internal method that verify if 'time' has elapsed since 
         all elements in 'group' have reached state 'state'.
     def _needs_reschedule(self, group, state, time):
         """ Internal method that verify if 'time' has elapsed since 
         all elements in 'group' have reached state 'state'.


@@ -634,11 +811,20 @@ class ResourceManager(Logger):
 
         """
         reschedule = False
 
         """
         reschedule = False

-        delay = reschedule_delay 
+        delay = self.reschedule_delay 

 
         # check state and time elapsed on all RMs
         for guid in group:
             rm = self.ec.get_resource(guid)
 
         # check state and time elapsed on all RMs
         for guid in group:
             rm = self.ec.get_resource(guid)

+            
+            # If one of the RMs this resource needs to wait for has FAILED
+            # and is critical we raise an exception
+            if rm.state == ResourceState.FAILED:
+                if not rm.get('critical'):
+                    continue
+                msg = "Resource can not wait for FAILED RM %d. Setting Resource to FAILED"
+                raise RuntimeError, msg
+

             # If the RM state is lower than the requested state we must
             # reschedule (e.g. if RM is READY but we required STARTED).
             if rm.state < state:
             # If the RM state is lower than the requested state we must
             # reschedule (e.g. if RM is READY but we required STARTED).
             if rm.state < state:


@@ -650,7 +836,9 @@ class ResourceManager(Logger):
             if time:
                 if state == ResourceState.DISCOVERED:
                     t = rm.discover_time
             if time:
                 if state == ResourceState.DISCOVERED:
                     t = rm.discover_time

-                if state == ResourceState.PROVISIONED:
+                elif state == ResourceState.RESERVED:
+                    t = rm.reserved_time
+                elif state == ResourceState.PROVISIONED:

                     t = rm.provision_time
                 elif state == ResourceState.READY:
                     t = rm.ready_time
                     t = rm.provision_time
                 elif state == ResourceState.READY:
                     t = rm.ready_time


@@ -658,6 +846,8 @@ class ResourceManager(Logger):
                     t = rm.start_time
                 elif state == ResourceState.STOPPED:
                     t = rm.stop_time
                     t = rm.start_time
                 elif state == ResourceState.STOPPED:
                     t = rm.stop_time

+                elif state == ResourceState.RELEASED:
+                    t = rm.release_time

                 else:
                     break
 
                 else:
                     break
 


@@ -692,7 +882,7 @@ class ResourceManager(Logger):
         """
 
         reschedule = False
         """
 
         reschedule = False

-        delay = reschedule_delay 
+        delay = self.reschedule_delay 

 
         ## evaluate if set conditions are met
 
 
         ## evaluate if set conditions are met
 


@@ -714,8 +904,11 @@ class ResourceManager(Logger):
         action 'START' are satisfied.
 
         """
         action 'START' are satisfied.
 
         """

+        #import pdb;pdb.set_trace()
+

         reschedule = False
         reschedule = False

-        delay = reschedule_delay 
+        delay = self.reschedule_delay 
+

 
         ## evaluate if conditions to start are met
         if self.ec.abort:
 
         ## evaluate if conditions to start are met
         if self.ec.abort:


@@ -756,7 +949,7 @@ class ResourceManager(Logger):
 
         """
         reschedule = False
 
         """
         reschedule = False

-        delay = reschedule_delay 
+        delay = self.reschedule_delay 

 
         ## evaluate if conditions to stop are met
         if self.ec.abort:
 
         ## evaluate if conditions to stop are met
         if self.ec.abort:


@@ -789,15 +982,16 @@ class ResourceManager(Logger):
 
         """
         reschedule = False
 
         """
         reschedule = False

-        delay = reschedule_delay 
+        delay = self.reschedule_delay 

 
         ## evaluate if conditions to deploy are met
         if self.ec.abort:
             return 
 
         # only can deploy when RM is either NEW, DISCOVERED or PROVISIONED 
 
         ## evaluate if conditions to deploy are met
         if self.ec.abort:
             return 
 
         # only can deploy when RM is either NEW, DISCOVERED or PROVISIONED 

-        if self.state not in [ResourceState.NEW, ResourceState.DISCOVERED, 
-                ResourceState.PROVISIONED]:
+        if self.state not in [ResourceState.NEW, ResourceState.DISCOVERED,
+                ResourceState.RESERVED, ResourceState.PROVISIONED]:
+            #### XXX: A.Q. IT SHOULD FAIL IF DEPLOY IS CALLED IN OTHER STATES!

             reschedule = True
             self.debug("---- RESCHEDULING DEPLOY ---- state %s " % self.state )
         else:
             reschedule = True
             self.debug("---- RESCHEDULING DEPLOY ---- state %s " % self.state )
         else:


@@ -812,7 +1006,7 @@ class ResourceManager(Logger):
                 #for guid in group:
                 #    rm = self.ec.get_resource(guid)
                 #    unmet.append((guid, rm._state))
                 #for guid in group:
                 #    rm = self.ec.get_resource(guid)
                 #    unmet.append((guid, rm._state))

-                #
+                

                 #self.debug("---- WAITED STATES ---- %s" % unmet )
 
                 reschedule, delay = self._needs_reschedule(group, state, time)
                 #self.debug("---- WAITED STATES ---- %s" % unmet )
 
                 reschedule, delay = self._needs_reschedule(group, state, time)


@@ -822,16 +1016,16 @@ class ResourceManager(Logger):
         if reschedule:
             self.ec.schedule(delay, self.deploy_with_conditions)
         else:
         if reschedule:
             self.ec.schedule(delay, self.deploy_with_conditions)
         else:

-            self.debug("----- STARTING ---- ")
+            self.debug("----- DEPLOYING ---- ")

             self.deploy()
 
             self.deploy()
 

-    def connect(self, guid):
+    def do_connect(self, guid):

         """ Performs actions that need to be taken upon associating RMs.
         This method should be redefined when necessary in child classes.
         """
         pass
 
         """ Performs actions that need to be taken upon associating RMs.
         This method should be redefined when necessary in child classes.
         """
         pass
 

-    def disconnect(self, guid):
+    def do_disconnect(self, guid):

         """ Performs actions that need to be taken upon disassociating RMs.
         This method should be redefined when necessary in child classes.
         """
         """ Performs actions that need to be taken upon disassociating RMs.
         This method should be redefined when necessary in child classes.
         """


@@ -849,45 +1043,91 @@ class ResourceManager(Logger):
         """
         # TODO: Validate!
         return True
         """
         # TODO: Validate!
         return True

-    
-    def set_started(self):
+
+    def do_discover(self):
+        self.set_discovered()
+
+    def do_reserve(self):
+        self.set_reserved()
+
+    def do_provision(self):
+        self.set_provisioned()
+
+    def do_start(self):
+        self.set_started()
+
+    def do_stop(self):
+        self.set_stopped()
+
+    def do_deploy(self):
+        self.set_ready()
+
+    def do_release(self):
+        self.set_released()
+
+    def do_fail(self):
+        self.set_failed()
+        self.ec.inform_failure(self.guid)
+
+    def set_started(self, time = None):

         """ Mark ResourceManager as STARTED """
         """ Mark ResourceManager as STARTED """

-        self.set_state(ResourceState.STARTED, "_start_time")
-        
-    def set_stopped(self):
+        self.set_state(ResourceState.STARTED, "_start_time", time)
+        self.debug("----- STARTED ---- ")
+
+    def set_stopped(self, time = None):

         """ Mark ResourceManager as STOPPED """
         """ Mark ResourceManager as STOPPED """

-        self.set_state(ResourceState.STOPPED, "_stop_time")
+        self.set_state(ResourceState.STOPPED, "_stop_time", time)
+        self.debug("----- STOPPED ---- ")

 
 

-    def set_ready(self):
+    def set_ready(self, time = None):

         """ Mark ResourceManager as READY """
         """ Mark ResourceManager as READY """

-        self.set_state(ResourceState.READY, "_ready_time")
+        self.set_state(ResourceState.READY, "_ready_time", time)
+        self.debug("----- READY ---- ")

 
 

-    def set_released(self):
+    def set_released(self, time = None):

         """ Mark ResourceManager as REALEASED """
         """ Mark ResourceManager as REALEASED """

-        self.set_state(ResourceState.RELEASED, "_release_time")
+        self.set_state(ResourceState.RELEASED, "_release_time", time)

 
 

-    def set_finished(self):
-        """ Mark ResourceManager as FINISHED """
-        self.set_state(ResourceState.FINISHED, "_finish_time")
+        msg = " %s guid %d ----- RELEASED ----- " % (self._rtype, self.guid)
+        logger = Logger(self._rtype)
+        logger.debug(msg)

 
 

-    def set_failed(self):
+    def set_failed(self, time = None):

         """ Mark ResourceManager as FAILED """
         """ Mark ResourceManager as FAILED """

-        self.set_state(ResourceState.FAILED, "_failed_time")
+        self.set_state(ResourceState.FAILED, "_failed_time", time)
+
+        msg = " %s guid %d ----- FAILED ----- " % (self._rtype, self.guid)
+        logger = Logger(self._rtype)
+        logger.debug(msg)

 
 

-    def set_discovered(self):
+    def set_discovered(self, time = None):

         """ Mark ResourceManager as DISCOVERED """
         """ Mark ResourceManager as DISCOVERED """

-        self.set_state(ResourceState.DISCOVERED, "_discover_time")
+        self.set_state(ResourceState.DISCOVERED, "_discover_time", time)
+        self.debug("----- DISCOVERED ---- ")

 
 

-    def set_provisioned(self):
+    def set_reserved(self, time = None):
+        """ Mark ResourceManager as RESERVED """
+        self.set_state(ResourceState.RESERVED, "_reserved_time", time)
+        self.debug("----- RESERVED ---- ")
+
+    def set_provisioned(self, time = None):

         """ Mark ResourceManager as PROVISIONED """
         """ Mark ResourceManager as PROVISIONED """

-        self.set_state(ResourceState.PROVISIONED, "_provision_time")
+        self.set_state(ResourceState.PROVISIONED, "_provision_time", time)
+        self.debug("----- PROVISIONED ---- ")
+
+    def set_state(self, state, state_time_attr, time = None):
+        """ Set the state of the RM while keeping a trace of the time """

 
 

-    def set_state(self, state, state_time_attr):

         # Ensure that RM state will not change after released
         if self._state == ResourceState.RELEASED:
             return 
         # Ensure that RM state will not change after released
         if self._state == ResourceState.RELEASED:
             return 

-   
-        setattr(self, state_time_attr, tnow())
+
+        time = time or tnow()
+        self.set_state_time(state, state_time_attr, time)
+  
+    def set_state_time(self, state, state_time_attr, time):
+        """ Set the time for the RM state change """
+        setattr(self, state_time_attr, time)

         self._state = state
 
 class ResourceFactory(object):
         self._state = state
 
 class ResourceFactory(object):


@@ -906,7 +1146,7 @@ class ResourceFactory(object):
     @classmethod
     def register_type(cls, rclass):
         """Register a new Ressource Manager"""
     @classmethod
     def register_type(cls, rclass):
         """Register a new Ressource Manager"""

-        cls._resource_types[rclass.rtype()] = rclass
+        cls._resource_types[rclass.get_rtype()] = rclass

 
     @classmethod
     def create(cls, rtype, ec, guid):
 
     @classmethod
     def create(cls, rtype, ec, guid):


@@ -915,7 +1155,7 @@ class ResourceFactory(object):
         return rclass(ec, guid)
 
 def populate_factory():
         return rclass(ec, guid)
 
 def populate_factory():

-    """Register all the possible RM that exists in the current version of Nepi.
+    """Find and rgister all available RMs

     """
     # Once the factory is populated, don't repopulate
     if not ResourceFactory.resource_types():
     """
     # Once the factory is populated, don't repopulate
     if not ResourceFactory.resource_types():


@@ -934,7 +1174,7 @@ def find_types():
     path = os.path.dirname(nepi.resources.__file__)
     search_path.add(path)
 
     path = os.path.dirname(nepi.resources.__file__)
     search_path.add(path)
 

-    types = []
+    types = set()

 
     for importer, modname, ispkg in pkgutil.walk_packages(search_path, 
             prefix = "nepi.resources."):
 
     for importer, modname, ispkg in pkgutil.walk_packages(search_path, 
             prefix = "nepi.resources."):


@@ -942,7 +1182,7 @@ def find_types():
         loader = importer.find_module(modname)
         
         try:
         loader = importer.find_module(modname)
         
         try:

-            # Notice: Repeated calls to load_module will act as a reload of teh module
+            # Notice: Repeated calls to load_module will act as a reload of the module

             if modname in sys.modules:
                 module = sys.modules.get(modname)
             else:
             if modname in sys.modules:
                 module = sys.modules.get(modname)
             else:


@@ -961,7 +1201,7 @@ def find_types():
                     continue
 
                 if issubclass(attr, ResourceManager):
                     continue
 
                 if issubclass(attr, ResourceManager):

-                    types.append(attr)
+                    types.add(attr)

 
                     if not modname in sys.modules:
                         sys.modules[modname] = module
 
                     if not modname in sys.modules:
                         sys.modules[modname] = module


@@ -975,4 +1215,3 @@ def find_types():
 
     return types
 
 
     return types
 

-