X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=src%2Fnepi%2Fcore%2Fexecute.py;h=5e0c5ea6b29214fdac16e9d52012389e179718fe;hb=1cf85539204432589217de408cd2eb37e3d68e6a;hp=bc8df21125f645e9836848acc96586eda42aca8b;hpb=3febf4984ace49f2552ff4b167126fc80d9c46b5;p=nepi.git

diff --git a/src/nepi/core/execute.py b/src/nepi/core/execute.py
index bc8df211..5e0c5ea6 100644
--- a/src/nepi/core/execute.py
+++ b/src/nepi/core/execute.py
@@ -1,182 +1,44 @@
-#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from nepi.core.attributes import Attribute, AttributesMap
-from nepi.util import proxy, validation
-from nepi.util.constants import STATUS_FINISHED, TIME_NOW
+from nepi.util import validation
+from nepi.util.constants import ApplicationStatus as AS, TestbedStatus as TS, TIME_NOW, DeploymentConfiguration as DC
 from nepi.util.parser._xml import XmlExperimentParser
 import sys
 import re
 import threading
 import ConfigParser
 import os
+import collections
+import functools
+import time
+import logging
+logging.basicConfig()
 
-ATTRIBUTE_PATTERN_BASE = re.compile(r"\{#\[(?P<label>[-a-zA-Z0-9._]*)\](?P<expr>(?P<component>\.addr\[[0-9]+\]|\.route\[[0-9]+\]|\.trace\[[0-9]+\]|).\[(?P<attribute>[-a-zA-Z0-9._]*)\])#}")
+ATTRIBUTE_PATTERN_BASE = re.compile(r"\{#\[(?P<label>[-a-zA-Z0-9._]*)\](?P<expr>(?P<component>\.addr\[[0-9]+\]|\.route\[[0-9]+\]|\.trace\[[-a-zA-Z0-9._]+\])?.\[(?P<attribute>[-a-zA-Z0-9._]*)\])#}")
 ATTRIBUTE_PATTERN_GUID_SUB = r"{#[%(guid)s]%(expr)s#}"
 COMPONENT_PATTERN = re.compile(r"(?P<kind>[a-z]*)\[(?P<index>.*)\]")
 
-class ConnectorType(object):
-    def __init__(self, testbed_id, factory_id, name, max = -1, min = 0):
-        super(ConnectorType, self).__init__()
-        if max == -1:
-            max = sys.maxint
-        elif max <= 0:
-                raise RuntimeError(
-             "The maximum number of connections allowed need to be more than 0")
-        if min < 0:
-            raise RuntimeError(
-             "The minimum number of connections allowed needs to be at least 0")
-        # connector_type_id -- univoquely identifies a connector type 
-        # across testbeds
-        self._connector_type_id = (testbed_id.lower(), factory_id.lower(), 
-                name.lower())
-        # name -- display name for the connector type
-        self._name = name
-        # max -- maximum amount of connections that this type support, 
-        # -1 for no limit
-        self._max = max
-        # min -- minimum amount of connections required by this type of connector
-        self._min = min
-        # from_connections -- connections where the other connector is the "From"
-        # to_connections -- connections where the other connector is the "To"
-        # keys in the dictionary correspond to the 
-        # connector_type_id for possible connections. The value is a tuple:
-        # (can_cross, connect)
-        # can_cross: indicates if the connection is allowed accros different
-        #    testbed instances
-        # code: is the connection function to be invoked when the elements
-        #    are connected
-        self._from_connections = dict()
-        self._to_connections = dict()
+def _undefer(deferred):
+    if hasattr(deferred, '_get'):
+        return deferred._get()
+    else:
+        return deferred
 
-    @property
-    def connector_type_id(self):
-        return self._connector_type_id
-
-    @property
-    def name(self):
-        return self._name
-
-    @property
-    def max(self):
-        return self._max
-
-    @property
-    def min(self):
-        return self._min
-
-    def add_from_connection(self, testbed_id, factory_id, name, can_cross, code):
-        self._from_connections[(testbed_id.lower(), factory_id.lower(),
-            name.lower())] = (can_cross, code)
-
-    def add_to_connection(self, testbed_id, factory_id, name, can_cross, code):
-        self._to_connections[(testbed_id.lower(), factory_id.lower(), 
-            name.lower())] = (can_cross, code)
-
-    def can_connect(self, testbed_id, factory_id, name, count, 
-            must_cross = False):
-        connector_type_id = (testbed_id.lower(), factory_id.lower(),
-            name.lower())
-        if connector_type_id in self._from_connections:
-            (can_cross, code) = self._from_connections[connector_type_id]
-        elif connector_type_id in self._to_connections:
-            (can_cross, code) = self._to_connections[connector_type_id]
-        else:
-            return False
-        return not must_cross or can_cross
-
-    def code_to_connect(self, testbed_id, factory_id, name):
-        connector_type_id = (testbed_id.lower(), factory_id.lower(), 
-            name.lower())        
-        if not connector_type_id in self._to_connections.keys():
-            return False
-        (can_cross, code) = self._to_connections[connector_type_id]
-        return code
-
-# TODO: create_function, start_function, stop_function, status_function 
-# need a definition!
-class Factory(AttributesMap):
-    def __init__(self, factory_id, create_function, start_function, 
-            stop_function, status_function, 
-            configure_function, preconfigure_function,
-            allow_addresses = False, allow_routes = False):
-        super(Factory, self).__init__()
-        self._factory_id = factory_id
-        self._allow_addresses = (allow_addresses == True)
-        self._allow_routes = (allow_routes == True)
-        self._create_function = create_function
-        self._start_function = start_function
-        self._stop_function = stop_function
-        self._status_function = status_function
-        self._configure_function = configure_function
-        self._preconfigure_function = preconfigure_function
-        self._connector_types = dict()
-        self._traces = list()
-        self._box_attributes = AttributesMap()
-
-    @property
-    def factory_id(self):
-        return self._factory_id
-
-    @property
-    def allow_addresses(self):
-        return self._allow_addresses
-
-    @property
-    def allow_routes(self):
-        return self._allow_routes
-
-    @property
-    def box_attributes(self):
-        return self._box_attributes
-
-    @property
-    def create_function(self):
-        return self._create_function
-
-    @property
-    def start_function(self):
-        return self._start_function
-
-    @property
-    def stop_function(self):
-        return self._stop_function
-
-    @property
-    def status_function(self):
-        return self._status_function
-
-    @property
-    def configure_function(self):
-        return self._configure_function
-
-    @property
-    def preconfigure_function(self):
-        return self._preconfigure_function
-
-    @property
-    def traces(self):
-        return self._traces
-
-    def connector_type(self, name):
-        return self._connector_types[name]
-
-    def add_connector_type(self, connector_type):
-        self._connector_types[connector_type.name] = connector_type
-
-    def add_trace(self, trace_id):
-        self._traces.append(trace_id)
-
-    def add_box_attribute(self, name, help, type, value = None, range = None,
-        allowed = None, flags = Attribute.NoFlags, validation_function = None):
-        self._box_attributes.add_attribute(name, help, type, value, range, 
-                allowed, flags, validation_function)
 
 class TestbedController(object):
     def __init__(self, testbed_id, testbed_version):
         self._testbed_id = testbed_id
         self._testbed_version = testbed_version
 
+    @property
+    def testbed_id(self):
+        return self._testbed_id
+
+    @property
+    def testbed_version(self):
+        return self._testbed_version
+
     @property
     def guids(self):
         raise NotImplementedError
@@ -202,8 +64,11 @@ class TestbedController(object):
         """Instructs creation of a connection between the given connectors"""
         raise NotImplementedError
 
-    def defer_cross_connect(self, guid, connector_type_name, cross_guid, 
-            cross_testbed_id, cross_factory_id, cross_connector_type_name):
+    def defer_cross_connect(self, 
+            guid, connector_type_name,
+            cross_guid, cross_testbed_guid,
+            cross_testbed_id, cross_factory_id,
+            cross_connector_type_name):
         """
         Instructs creation of a connection between the given connectors 
         of different testbed instances
@@ -218,7 +83,8 @@ class TestbedController(object):
         """Instructs the addition of an address"""
         raise NotImplementedError
 
-    def defer_add_route(self, guid, destination, netprefix, nexthop):
+    def defer_add_route(self, guid, destination, netprefix, nexthop, 
+            metric = 0, device = None):
         """Instructs the addition of a route"""
         raise NotImplementedError
 
@@ -233,10 +99,25 @@ class TestbedController(object):
         """
         raise NotImplementedError
 
-    def do_connect(self):
+    def do_connect_init(self):
+        """
+        After do_connect_init all internal connections between testbed elements
+        are initiated
+        """
+        raise NotImplementedError
+
+    def do_connect_compl(self):
         """
         After do_connect all internal connections between testbed elements
-        are done
+        are completed
+        """
+        raise NotImplementedError
+
+    def do_preconfigure(self):
+        """
+        Done just before resolving netrefs, after connection, before cross connections,
+        useful for early stages of configuration, for setting up stuff that might be
+        required for netref resolution.
         """
         raise NotImplementedError
 
@@ -244,10 +125,21 @@ class TestbedController(object):
         """After do_configure elements are configured"""
         raise NotImplementedError
 
-    def do_cross_connect(self):
+    def do_prestart(self):
+        """Before do_start elements are prestart-configured"""
+        raise NotImplementedError
+
+    def do_cross_connect_init(self, cross_data):
+        """
+        After do_cross_connect_init initiation of all external connections 
+        between different testbed elements is performed
+        """
+        raise NotImplementedError
+
+    def do_cross_connect_compl(self, cross_data):
         """
-        After do_cross_connect all external connections between different testbed 
-        elements are done
+        After do_cross_connect_compl completion of all external connections 
+        between different testbed elements is performed
         """
         raise NotImplementedError
 
@@ -257,10 +149,27 @@ class TestbedController(object):
     def stop(self):
         raise NotImplementedError
 
-    def set(self, time, guid, name, value):
+    def recover(self):
+        """
+        On testbed recovery (if recovery is a supported policy), the controller
+        instance will be re-created and the following sequence invoked:
+        
+            do_setup
+            defer_X - programming the testbed with persisted execution values
+                (not design values). Execution values (ExecImmutable attributes)
+                should be enough to recreate the testbed's state.
+            *recover*
+            <cross-connection methods>
+            
+        Start will not be called, and after cross connection invocations,
+        the testbed is supposed to be fully functional again.
+        """
         raise NotImplementedError
 
-    def get(self, time, guid, name):
+    def set(self, guid, name, value, time = TIME_NOW):
+        raise NotImplementedError
+
+    def get(self, guid, name, time = TIME_NOW):
         raise NotImplementedError
     
     def get_route(self, guid, index, attribute):
@@ -283,160 +192,557 @@ class TestbedController(object):
         """
         raise NotImplementedError
 
+    def get_attribute_list(self, guid, filter_flags = None, exclude = False):
+        raise NotImplementedError
+
+    def get_factory_id(self, guid):
+        raise NotImplementedError
+
     def action(self, time, guid, action):
         raise NotImplementedError
 
     def status(self, guid):
         raise NotImplementedError
+    
+    def testbed_status(self):
+        raise NotImplementedError
 
     def trace(self, guid, trace_id, attribute='value'):
         raise NotImplementedError
 
+    def traces_info(self):
+        """ dictionary of dictionaries:
+            traces_info = dict({
+                guid = dict({
+                    trace_id = dict({
+                            host = host,
+                            filepath = filepath,
+                            filesize = size in bytes,
+                        })
+                })
+            })"""
+        raise NotImplementedError
+
     def shutdown(self):
         raise NotImplementedError
 
 class ExperimentController(object):
     def __init__(self, experiment_xml, root_dir):
-        self._experiment_xml = experiment_xml
+        self._experiment_design_xml = experiment_xml
+        self._experiment_execute_xml = None
         self._testbeds = dict()
-        self._access_config = dict()
-        self._netrefs = dict()
+        self._deployment_config = dict()
+        self._netrefs = collections.defaultdict(set)
+        self._testbed_netrefs = collections.defaultdict(set)
+        self._cross_data = dict()
         self._root_dir = root_dir
+        self._netreffed_testbeds = set()
+        self._guids_in_testbed_cache = dict()
+        self._failed_testbeds = set()
+        self._started_time = None
+        self._stopped_time = None
+        self._testbed_order = []
+      
+        self._logger = logging.getLogger('nepi.core.execute')
+        level = logging.ERROR
+        if os.environ.get("NEPI_CONTROLLER_LOGLEVEL", 
+                DC.ERROR_LEVEL) == DC.DEBUG_LEVEL:
+            level = logging.DEBUG
+        self._logger.setLevel(level)
+ 
+        if experiment_xml is None and root_dir is not None:
+            # Recover
+            self.load_experiment_xml()
+            self.load_execute_xml()
+        else:
+            self.persist_experiment_xml()
 
-        self.persist_experiment_xml()
+    @property
+    def experiment_design_xml(self):
+        return self._experiment_design_xml
 
     @property
-    def experiment_xml(self):
-        return self._experiment_xml
+    def experiment_execute_xml(self):
+        return self._experiment_execute_xml
+
+    @property
+    def started_time(self):
+        return self._started_time
+
+    @property
+    def stopped_time(self):
+        return self._stopped_time
+
+    @property
+    def guids(self):
+        guids = list()
+        for testbed_guid in self._testbeds.keys():
+            _guids = self._guids_in_testbed(testbed_guid)
+            if _guids:
+                guids.extend(_guids)
+        return guids
 
     def persist_experiment_xml(self):
-        xml_path = os.path.join(self._root_dir, "experiment.xml")
+        xml_path = os.path.join(self._root_dir, "experiment-design.xml")
+        f = open(xml_path, "w")
+        f.write(self._experiment_design_xml)
+        f.close()
+
+    def persist_execute_xml(self):
+        xml_path = os.path.join(self._root_dir, "experiment-execute.xml")
         f = open(xml_path, "w")
-        f.write(self._experiment_xml)
+        f.write(self._experiment_execute_xml)
+        f.close()
+
+    def load_experiment_xml(self):
+        xml_path = os.path.join(self._root_dir, "experiment-design.xml")
+        f = open(xml_path, "r")
+        self._experiment_design_xml = f.read()
         f.close()
 
-    def set_access_configuration(self, testbed_guid, access_config):
-        self._access_config[testbed_guid] = access_config
+    def load_execute_xml(self):
+        xml_path = os.path.join(self._root_dir, "experiment-execute.xml")
+        f = open(xml_path, "r")
+        self._experiment_execute_xml = f.read()
+        f.close()
+
+    def trace(self, guid, trace_id, attribute='value'):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.trace(guid, trace_id, attribute)
+        raise RuntimeError("No element exists with guid %d" % guid)    
 
-    def trace(self, testbed_guid, guid, trace_id, attribute='value'):
-        return self._testbeds[testbed_guid].trace(guid, trace_id, attribute)
+    def traces_info(self):
+        traces_info = dict()
+        for guid, testbed in self._testbeds.iteritems():
+            tinfo = testbed.traces_info()
+            if tinfo:
+                traces_info[guid] = testbed.traces_info()
+        return traces_info
 
     @staticmethod
     def _parallel(callables):
-        threads = [ threading.Thread(target=callable) for callable in callables ]
+        excs = []
+        def wrap(callable):
+            def wrapped(*p, **kw):
+                try:
+                    callable(*p, **kw)
+                except:
+                    logging.exception("Exception occurred in asynchronous thread:")
+                    excs.append(sys.exc_info())
+            try:
+                wrapped = functools.wraps(callable)(wrapped)
+            except:
+                # functools.partial not wrappable
+                pass
+            return wrapped
+        threads = [ threading.Thread(target=wrap(callable)) for callable in callables ]
         for thread in threads:
             thread.start()
         for thread in threads:
             thread.join()
+        for exc in excs:
+            eTyp, eVal, eLoc = exc
+            raise eTyp, eVal, eLoc
 
     def start(self):
-        self._create_testbed_instances()
-        
-        # persist testbed connection data, for potential recovery
-        self._persist_testbed_proxies()
-        
-        # perform setup in parallel for all test beds,
-        # wait for all threads to finish
-        self._parallel([testbed.do_setup 
-                        for testbed in self._testbeds.itervalues()])
+        self._started_time = time.time() 
+        self._start()
+
+    def _start(self, recover = False):
+        parser = XmlExperimentParser()
         
-        # perform create-connect in parallel, wait
-        # (internal connections only)
-        self._parallel([lambda : (testbed.do_create(), 
-                                  testbed.do_connect(),
-                                  testbed.do_preconfigure())
-                        for testbed in self._testbeds.itervalues()])
+        if recover:
+            xml = self._experiment_execute_xml
+        else:
+            xml = self._experiment_design_xml
+        data = parser.from_xml_to_data(xml)
+
+        # instantiate testbed controllers
+        to_recover, to_restart = self._init_testbed_controllers(data, recover)
+        all_restart = set(to_restart)
         
-        # resolve netrefs
-        self.do_netrefs(fail_if_undefined=True)
+        if not recover:
+            # persist testbed connection data, for potential recovery
+            self._persist_testbed_proxies()
+        else:
+            # recover recoverable controllers
+            for guid in to_recover:
+                try:
+                    self._testbeds[guid].do_setup()
+                    self._testbeds[guid].recover()
+                except:
+                    self._logger.exception("During recovery of testbed %s", guid)
+                    
+                    # Mark failed
+                    self._failed_testbeds.add(guid)
+    
+        def steps_to_configure(self, allowed_guids):
+            # perform setup in parallel for all test beds,
+            # wait for all threads to finish
+
+            self._logger.debug("ExperimentController: Starting parallel do_setup")
+            self._parallel([testbed.do_setup 
+                            for guid,testbed in self._testbeds.iteritems()
+                            if guid in allowed_guids])
+       
+            # perform create-connect in parallel, wait
+            # (internal connections only)
+            self._logger.debug("ExperimentController: Starting parallel do_create")
+            self._parallel([testbed.do_create
+                            for guid,testbed in self._testbeds.iteritems()
+                            if guid in allowed_guids])
+
+            self._logger.debug("ExperimentController: Starting parallel do_connect_init")
+            self._parallel([testbed.do_connect_init
+                            for guid,testbed in self._testbeds.iteritems()
+                            if guid in allowed_guids])
+
+            self._logger.debug("ExperimentController: Starting parallel do_connect_fin")
+            self._parallel([testbed.do_connect_compl
+                            for guid,testbed in self._testbeds.iteritems()
+                            if guid in allowed_guids])
+
+            self._logger.debug("ExperimentController: Starting parallel do_preconfigure")
+            self._parallel([testbed.do_preconfigure
+                            for guid,testbed in self._testbeds.iteritems()
+                            if guid in allowed_guids])
+            self._clear_caches()
+            
+            # Store testbed order
+            self._testbed_order.append(allowed_guids)
+
+        steps_to_configure(self, to_restart)
+
+        if self._netreffed_testbeds:
+            self._logger.debug("ExperimentController: Resolving netreffed testbeds")
+            # initally resolve netrefs
+            self.do_netrefs(data, fail_if_undefined=False)
+            
+            # rinse and repeat, for netreffed testbeds
+            netreffed_testbeds = set(self._netreffed_testbeds)
+
+            to_recover, to_restart = self._init_testbed_controllers(data, recover)
+            all_restart.update(to_restart)
+            
+            if not recover:
+                # persist testbed connection data, for potential recovery
+                self._persist_testbed_proxies()
+            else:
+                # recover recoverable controllers
+                for guid in to_recover:
+                    try:
+                        self._testbeds[guid].do_setup()
+                        self._testbeds[guid].recover()
+                    except:
+                        self._logger.exception("During recovery of testbed %s", guid)
+
+                        # Mark failed
+                        self._failed_testbeds.add(guid)
+
+            # configure dependant testbeds
+            steps_to_configure(self, to_restart)
         
+        all_restart = [ self._testbeds[guid] for guid in all_restart ]
+            
+        # final netref step, fail if anything's left unresolved
+        self._logger.debug("ExperimentController: Resolving do_netrefs")
+        self.do_netrefs(data, fail_if_undefined=False)
+       
+        # Only now, that netref dependencies have been solve, it is safe to
+        # program cross_connections
+        self._logger.debug("ExperimentController: Programming testbed cross-connections")
+        self._program_testbed_cross_connections(data)
+ 
         # perform do_configure in parallel for al testbeds
         # (it's internal configuration for each)
+        self._logger.debug("ExperimentController: Starting parallel do_configure")
         self._parallel([testbed.do_configure
-                        for testbed in self._testbeds.itervalues()])
+                        for testbed in all_restart])
+
+        self._clear_caches()
 
+        #print >>sys.stderr, "DO IT"
+        #import time
+        #time.sleep(60)
+        
         # cross-connect (cannot be done in parallel)
-        for testbed in self._testbeds.values():
-            testbed.do_cross_connect()
+        self._logger.debug("ExperimentController: Starting cross-connect")
+        for guid, testbed in self._testbeds.iteritems():
+            cross_data = self._get_cross_data(guid)
+            testbed.do_cross_connect_init(cross_data)
+        for guid, testbed in self._testbeds.iteritems():
+            cross_data = self._get_cross_data(guid)
+            testbed.do_cross_connect_compl(cross_data)
+       
+        self._clear_caches()
+
+        # Last chance to configure (parallel on all testbeds)
+        self._logger.debug("ExperimentController: Starting parallel do_prestart")
+        self._parallel([testbed.do_prestart
+                        for testbed in all_restart])
+
+        # final netref step, fail if anything's left unresolved
+        self.do_netrefs(data, fail_if_undefined=True)
+ 
+        self._clear_caches()
         
+        if not recover:
+            # update execution xml with execution-specific values
+            # TODO: BUG! BUggy code! cant stand all serializing all attribute values (ej: tun_key which is non ascci)"
+            self._update_execute_xml()
+            self.persist_execute_xml()
+
         # start experiment (parallel start on all testbeds)
+        self._logger.debug("ExperimentController: Starting parallel do_start")
         self._parallel([testbed.start
-                        for testbed in self._testbeds.itervalues()])
+                        for testbed in all_restart])
+
+        self._clear_caches()
+
+    def _clear_caches(self):
+        # Cleaning cache for safety.
+        self._guids_in_testbed_cache = dict()
 
     def _persist_testbed_proxies(self):
-        TRANSIENT = ('Recover',)
+        TRANSIENT = (DC.RECOVER,)
         
         # persist access configuration for all testbeds, so that
         # recovery mode can reconnect to them if it becomes necessary
         conf = ConfigParser.RawConfigParser()
-        for testbed_guid, testbed_config in self._access_config.iteritems():
+        for testbed_guid, testbed_config in self._deployment_config.iteritems():
             testbed_guid = str(testbed_guid)
             conf.add_section(testbed_guid)
-            for attr in testbed_config.attributes_name:
+            for attr in testbed_config.get_attribute_list():
                 if attr not in TRANSIENT:
-                    conf.set(testbed_guid, attr, 
-                        testbed_config.get_attribute_value(attr))
+                    value = testbed_config.get_attribute_value(attr)
+                    if value is not None:
+                        conf.set(testbed_guid, attr, value)
         
-        f = open(os.path.join(self._root_dir, 'access_config.ini'), 'w')
+        f = open(os.path.join(self._root_dir, 'deployment_config.ini'), 'w')
         conf.write(f)
         f.close()
     
     def _load_testbed_proxies(self):
         TYPEMAP = {
-            STRING : 'get',
-            INTEGER : 'getint',
-            FLOAT : 'getfloat',
-            BOOLEAN : 'getboolean',
+            Attribute.STRING : 'get',
+            Attribute.BOOL : 'getboolean',
+            Attribute.ENUM : 'get',
+            Attribute.DOUBLE : 'getfloat',
+            Attribute.INTEGER : 'getint',
         }
         
+        TRANSIENT = (DC.RECOVER,)
+        
+        # deferred import because proxy needs
+        # our class definitions to define proxies
+        import nepi.util.proxy as proxy
+        
         conf = ConfigParser.RawConfigParser()
-        conf.read(os.path.join(self._root_dir, 'access_config.ini'))
+        conf.read(os.path.join(self._root_dir, 'deployment_config.ini'))
         for testbed_guid in conf.sections():
             testbed_config = proxy.AccessConfiguration()
-            for attr in conf.options(testbed_guid):
-                testbed_config.set_attribute_value(attr, 
-                    conf.get(testbed_guid, attr) )
-                
             testbed_guid = str(testbed_guid)
-            conf.add_section(testbed_guid)
-            for attr in testbed_config.attributes_name:
+            for attr in testbed_config.get_attribute_list():
                 if attr not in TRANSIENT:
                     getter = getattr(conf, TYPEMAP.get(
                         testbed_config.get_attribute_type(attr),
                         'get') )
-                    testbed_config.set_attribute_value(
-                        testbed_guid, attr, getter(attr))
+                    try:
+                        value = getter(testbed_guid, attr)
+                        testbed_config.set_attribute_value(attr, value)
+                    except ConfigParser.NoOptionError:
+                        # Leave default
+                        pass
     
     def _unpersist_testbed_proxies(self):
         try:
-            os.remove(os.path.join(self._root_dir, 'access_config.ini'))
+            os.remove(os.path.join(self._root_dir, 'deployment_config.ini'))
         except:
             # Just print exceptions, this is just cleanup
-            import traceback
-            traceback.print_exc(file=sys.stderr)
+            self._logger.exception("Loading testbed configuration")
+
+    def _update_execute_xml(self):
+        # For all testbeds,
+        #   For all elements in testbed,
+        #       - gather immutable execute-readable attribuets lists
+        #         asynchronously
+        # Generate new design description from design xml
+        # (Wait for attributes lists - implicit syncpoint)
+        # For all testbeds,
+        #   For all elements in testbed,
+        #       - gather all immutable execute-readable attribute
+        #         values, asynchronously
+        # (Wait for attribute values - implicit syncpoint)
+        # For all testbeds,
+        #   For all elements in testbed,
+        #       - inject non-None values into new design
+        # Generate execute xml from new design
+
+        attribute_lists = dict(
+            (testbed_guid, collections.defaultdict(dict))
+            for testbed_guid in self._testbeds
+        )
+        
+        for testbed_guid, testbed in self._testbeds.iteritems():
+            guids = self._guids_in_testbed(testbed_guid)
+            for guid in guids:
+                attribute_lists[testbed_guid][guid] = \
+                    testbed.get_attribute_list_deferred(guid, Attribute.ExecImmutable)
+        
+        parser = XmlExperimentParser()
+        execute_data = parser.from_xml_to_data(self._experiment_design_xml)
+
+        attribute_values = dict(
+            (testbed_guid, collections.defaultdict(dict))
+            for testbed_guid in self._testbeds
+        )
+        
+        for testbed_guid, testbed_attribute_lists in attribute_lists.iteritems():
+            testbed = self._testbeds[testbed_guid]
+            for guid, attribute_list in testbed_attribute_lists.iteritems():
+                attribute_list = _undefer(attribute_list)
+                attribute_values[testbed_guid][guid] = dict(
+                    (attribute, testbed.get_deferred(guid, attribute))
+                    for attribute in attribute_list
+                )
+        
+        for testbed_guid, testbed_attribute_values in attribute_values.iteritems():
+            for guid, attribute_values in testbed_attribute_values.iteritems():
+                for attribute, value in attribute_values.iteritems():
+                    value = _undefer(value)
+                    if value is not None:
+                        execute_data.add_attribute_data(guid, attribute, value)
+        
+        self._experiment_execute_xml = parser.to_xml(data=execute_data)
 
     def stop(self):
        for testbed in self._testbeds.values():
            testbed.stop()
        self._unpersist_testbed_proxies()
+       self._stopped_time = time.time() 
    
     def recover(self):
         # reload perviously persisted testbed access configurations
+        self._failed_testbeds.clear()
         self._load_testbed_proxies()
-        
-        # recreate testbed proxies by reconnecting only
-        self._create_testbed_instances(recover=True)
+
+        # re-program testbeds that need recovery
+        self._start(recover = True)
 
     def is_finished(self, guid):
-        for testbed in self._testbeds.values():
-            for guid_ in testbed.guids:
-                if guid_ == guid:
-                    return testbed.status(guid) == STATUS_FINISHED
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.status(guid) == AS.STATUS_FINISHED
+        raise RuntimeError("No element exists with guid %d" % guid)    
+    
+    def _testbed_recovery_policy(self, guid, data = None):
+        if data is None:
+            parser = XmlExperimentParser()
+            data = parser.from_xml_to_data(self._experiment_design_xml)
+        
+        return data.get_attribute_data(guid, DC.RECOVERY_POLICY)
+
+    def status(self, guid):
+        if guid in self._testbeds:
+            # guid is a testbed
+            # report testbed status
+            if guid in self._failed_testbeds:
+                return TS.STATUS_FAILED
+            else:
+                try:
+                    return self._testbeds[guid].status()
+                except:
+                    return TS.STATUS_UNRESPONSIVE
+        else:
+            # guid is an element
+            testbed = self._testbed_for_guid(guid)
+            if testbed is not None:
+                return testbed.status(guid)
+            else:
+                return AS.STATUS_UNDETERMINED
+
+    def set(self, guid, name, value, time = TIME_NOW):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            testbed.set(guid, name, value, time)
+        else:
+            raise RuntimeError("No element exists with guid %d" % guid)    
+
+    def get(self, guid, name, time = TIME_NOW):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.get(guid, name, time)
+        raise RuntimeError("No element exists with guid %d" % guid)    
+
+    def get_deferred(self, guid, name, time = TIME_NOW):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.get_deferred(guid, name, time)
+        raise RuntimeError("No element exists with guid %d" % guid)    
+
+    def get_factory_id(self, guid):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.get_factory_id(guid)
+        raise RuntimeError("No element exists with guid %d" % guid)    
+
+    def get_testbed_id(self, guid):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.testbed_id
+        raise RuntimeError("No element exists with guid %d" % guid)    
+
+    def get_testbed_version(self, guid):
+        testbed = self._testbed_for_guid(guid)
+        if testbed != None:
+            return testbed.testbed_version
         raise RuntimeError("No element exists with guid %d" % guid)    
 
     def shutdown(self):
-       for testbed in self._testbeds.values():
-           testbed.shutdown()
+        exceptions = list()
+        ordered_testbeds = set()
+
+        def shutdown_testbed(guid):
+            try:
+                testbed = self._testbeds[guid]
+                ordered_testbeds.add(guid)
+                testbed.shutdown()
+            except:
+                exceptions.append(sys.exc_info())
+                
+        self._logger.debug("ExperimentController: Starting parallel shutdown")
+        
+        for testbed_guids in reversed(self._testbed_order):
+            testbed_guids = set(testbed_guids) - ordered_testbeds
+            self._logger.debug("ExperimentController: Shutting down %r", testbed_guids)
+            self._parallel([functools.partial(shutdown_testbed, guid)
+                            for guid in testbed_guids])
+        remaining_guids = set(self._testbeds) - ordered_testbeds
+        if remaining_guids:
+            self._logger.debug("ExperimentController: Shutted down %r", ordered_testbeds)
+            self._logger.debug("ExperimentController: Shutting down %r", remaining_guids)
+            self._parallel([functools.partial(shutdown_testbed, guid)
+                            for guid in remaining_guids])
+            
+        for exc_info in exceptions:
+            raise exc_info[0], exc_info[1], exc_info[2]
+
+    def _testbed_for_guid(self, guid):
+        for testbed_guid in self._testbeds.keys():
+            if guid in self._guids_in_testbed(testbed_guid):
+                if testbed_guid in self._failed_testbeds:
+                    return None
+                return self._testbeds[testbed_guid]
+        return None
+
+    def _guids_in_testbed(self, testbed_guid):
+        if testbed_guid not in self._testbeds:
+            return set()
+        if testbed_guid not in self._guids_in_testbed_cache:
+            self._guids_in_testbed_cache[testbed_guid] = \
+                set(self._testbeds[testbed_guid].guids)
+        return self._guids_in_testbed_cache[testbed_guid]
 
     @staticmethod
     def _netref_component_split(component):
@@ -446,144 +752,429 @@ class ExperimentController(object):
         else:
             return component, None
 
-    def do_netrefs(self, fail_if_undefined = False):
-        COMPONENT_GETTERS = {
-            'addr' :
-                lambda testbed, guid, index, name : 
-                    testbed.get_address(guid, index, name),
-            'route' :
-                lambda testbed, guid, index, name : 
-                    testbed.get_route(guid, index, name),
-            'trace' :
-                lambda testbed, guid, index, name : 
-                    testbed.trace(guid, index, name),
-            '' : 
-                lambda testbed, guid, index, name : 
-                    testbed.get(TIME_NOW, guid, name),
-        }
+    _NETREF_COMPONENT_GETTERS = {
+        'addr':
+            lambda testbed, guid, index, name: 
+                testbed.get_address(guid, int(index), name),
+        'route' :
+            lambda testbed, guid, index, name: 
+                testbed.get_route(guid, int(index), name),
+        'trace' :
+            lambda testbed, guid, index, name: 
+                testbed.trace(guid, index, attribute = name),
+        '' : 
+            lambda testbed, guid, index, name: 
+                testbed.get(guid, name),
+    }
+    
+    def resolve_netref_value(self, value, failval = None):
+        rv = failval
+        while True:
+            for match in ATTRIBUTE_PATTERN_BASE.finditer(value):
+                label = match.group("label")
+                if label.startswith('GUID-'):
+                    ref_guid = int(label[5:])
+                    if ref_guid:
+                        expr = match.group("expr")
+                        component = (match.group("component") or "")[1:] # skip the dot
+                        attribute = match.group("attribute")
+                        
+                        # split compound components into component kind and index
+                        # eg: 'addr[0]' -> ('addr', '0')
+                        component, component_index = self._netref_component_split(component)
+
+                        # find object and resolve expression
+                        for ref_testbed_guid, ref_testbed in self._testbeds.iteritems():
+                            if component not in self._NETREF_COMPONENT_GETTERS:
+                                raise ValueError, "Malformed netref: %r - unknown component" % (expr,)
+                            elif ref_guid not in self._guids_in_testbed(ref_testbed_guid):
+                                pass
+                            else:
+                                ref_value = self._NETREF_COMPONENT_GETTERS[component](
+                                    ref_testbed, ref_guid, component_index, attribute)
+                                if ref_value:
+                                    value = rv = value.replace(match.group(), ref_value)
+                                    break
+                        else:
+                            # unresolvable netref
+                            return failval
+                        break
+            else:
+                break
+        return rv
+    
+    def do_netrefs(self, data, fail_if_undefined = False):
+        # element netrefs
+        for (testbed_guid, guid), attrs in self._netrefs.items():
+            testbed = self._testbeds.get(testbed_guid)
+            if testbed is not None:
+                for name in set(attrs):
+                    value = testbed.get(guid, name)
+                    if isinstance(value, basestring):
+                        ref_value = self.resolve_netref_value(value)
+                        if ref_value is not None:
+                            testbed.set(guid, name, ref_value)
+                            attrs.remove(name)
+                        elif fail_if_undefined:
+                            raise ValueError, "Unresolvable netref in: %r=%r" % (name,value,)
+                if not attrs:
+                    del self._netrefs[(testbed_guid, guid)]
         
-        for (testbed_guid, guid), attrs in self._netrefs.iteritems():
-            testbed = self._testbeds[testbed_guid]
-            for name in attrs:
-                value = testbed.get(TIME_NOW, guid, name)
-                if isinstance(value, basestring):
-                    match = ATTRIBUTE_PATTERN_BASE.search(value)
-                    if match:
-                        label = match.group("label")
-                        if label.startswith('GUID-'):
-                            ref_guid = int(label[5:])
-                            if ref_guid:
-                                expr = match.group("expr")
-                                component = match.group("component")[1:] # skip the dot
-                                attribute = match.group("attribute")
-                                
-                                # split compound components into component kind and index
-                                # eg: 'addr[0]' -> ('addr', '0')
-                                component, component_index = self._netref_component_split(component)
-                                
-                                # find object and resolve expression
-                                for ref_testbed in self._testbeds.itervalues():
-                                    if component not in COMPONENT_GETTERS:
-                                        raise ValueError, "Malformed netref: %r - unknown component" % (expr,)
-                                    else:
-                                        ref_value = COMPONENT_GETTERS[component](
-                                            ref_testbed, ref_guid, component_index, attribute)
-                                        if ref_value:
-                                            testbed.set(TIME_NOW, guid, name, 
-                                                value.replace(match.group(), ref_value))
-                                            break
-                                else:
-                                    # couldn't find value
-                                    if fail_if_undefined:
-                                        raise ValueError, "Unresolvable GUID: %r, in netref: %r" % (ref_guid, expr)
-
-    def _create_testbed_instances(self, recover = False):
-        parser = XmlExperimentParser()
-        data = parser.from_xml_to_data(self._experiment_xml)
+        # testbed netrefs
+        for testbed_guid, attrs in self._testbed_netrefs.items():
+            tb_data = dict(data.get_attribute_data(testbed_guid))
+            if data:
+                for name in set(attrs):
+                    value = tb_data.get(name)
+                    if isinstance(value, basestring):
+                        ref_value = self.resolve_netref_value(value)
+                        if ref_value is not None:
+                            data.set_attribute_data(testbed_guid, name, ref_value)
+                            attrs.remove(name)
+                        elif fail_if_undefined:
+                            raise ValueError, "Unresolvable netref in: %r" % (value,)
+                if not attrs:
+                    del self._testbed_netrefs[testbed_guid]
+        
+
+    def _init_testbed_controllers(self, data, recover = False):
+        blacklist_testbeds = set(self._testbeds)
         element_guids = list()
         label_guids = dict()
         data_guids = data.guids
-        netrefs = self._netrefs
+        to_recover = set()
+        to_restart = set()
+
+        # gather label associations
         for guid in data_guids:
-            if data.is_testbed_data(guid):
-                (testbed_id, testbed_version) = data.get_testbed_data(guid)
-                access_config = None if guid not in self._access_config else\
-                        self._access_config[guid]
-                
-                if recover and access_config is None:
-                    # need to create one
-                    access_config = self._access_config[guid] = proxy.AccessConfiguration()
-                if access_config is not None:
-                    # force recovery mode 
-                    access_config.set_attribute_value("recover",recover)
-                
-                testbed = proxy.create_testbed_instance(testbed_id, 
-                        testbed_version, access_config)
-                for (name, value) in data.get_attribute_data(guid):
-                    testbed.defer_configure(name, value)
-                self._testbeds[guid] = testbed
-            else:
-                element_guids.append(guid)
+            if not data.is_testbed_data(guid):
+                (testbed_guid, factory_id) = data.get_box_data(guid)
                 label = data.get_attribute_data(guid, "label")
                 if label is not None:
                     if label in label_guids:
                         raise RuntimeError, "Label %r is not unique" % (label,)
                     label_guids[label] = guid
+
+        # create testbed controllers
+        for guid in data_guids:
+            if data.is_testbed_data(guid):
+                if guid not in self._testbeds:
+                    try:
+                        self._create_testbed_controller(
+                            guid, data, element_guids, recover)
+                        if recover:
+                            # Already programmed
+                            blacklist_testbeds.add(guid)
+                        else:
+                            to_restart.add(guid)
+                    except:
+                        if recover:
+                            policy = self._testbed_recovery_policy(guid, data=data)
+                            if policy == DC.POLICY_RECOVER:
+                                self._create_testbed_controller(
+                                    guid, data, element_guids, False)
+                                to_recover.add(guid)
+                            elif policy == DC.POLICY_RESTART:
+                                self._create_testbed_controller(
+                                    guid, data, element_guids, False)
+                                to_restart.add(guid)
+                            else:
+                                # Mark failed
+                                self._failed_testbeds.add(guid)
+                        else:
+                            raise
+        
+        # queue programmable elements
+        #  - that have not been programmed already (blacklist_testbeds)
+        #  - including recovered or restarted testbeds
+        #  - but those that have no unresolved netrefs
         for guid in data_guids:
             if not data.is_testbed_data(guid):
-                for name, value in data.get_attribute_data(guid):
-                    if isinstance(value, basestring):
-                        match = ATTRIBUTE_PATTERN_BASE.search(value)
-                        if match:
+                (testbed_guid, factory_id) = data.get_box_data(guid)
+                if testbed_guid not in blacklist_testbeds:
+                    element_guids.append(guid)
+
+        # replace references to elements labels for its guid
+        self._resolve_labels(data, data_guids, label_guids)
+    
+        # program testbed controllers
+        if element_guids:
+            self._program_testbed_controllers(element_guids, data)
+        
+        return to_recover, to_restart
+
+    def _resolve_labels(self, data, data_guids, label_guids):
+        netrefs = self._netrefs
+        testbed_netrefs = self._testbed_netrefs
+        for guid in data_guids:
+            for name, value in data.get_attribute_data(guid):
+                if isinstance(value, basestring):
+                    while True:
+                        for match in ATTRIBUTE_PATTERN_BASE.finditer(value):
                             label = match.group("label")
                             if not label.startswith('GUID-'):
                                 ref_guid = label_guids.get(label)
                                 if ref_guid is not None:
-                                    value = ATTRIBUTE_PATTERN_BASE.sub(
+                                    value = value.replace(
+                                        match.group(),
                                         ATTRIBUTE_PATTERN_GUID_SUB % dict(
-                                            guid='GUID-%d' % (ref_guid,),
-                                            expr=match.group("expr"),
-                                            label=label), 
-                                        value)
+                                            guid = 'GUID-%d' % (ref_guid,),
+                                            expr = match.group("expr"),
+                                            label = label)
+                                    )
                                     data.set_attribute_data(guid, name, value)
                                     
                                     # memorize which guid-attribute pairs require
                                     # postprocessing, to avoid excessive controller-testbed
                                     # communication at configuration time
                                     # (which could require high-latency network I/O)
-                                    (testbed_guid, factory_id) = data.get_box_data(guid)
-                                    netrefs.setdefault((testbed_guid,guid),set()).add(name)
-        if not recover:
-            self._program_testbed_instances(element_guids, data)
+                                    if not data.is_testbed_data(guid):
+                                        (testbed_guid, factory_id) = data.get_box_data(guid)
+                                        netrefs[(testbed_guid, guid)].add(name)
+                                    else:
+                                        testbed_netrefs[guid].add(name)
+                                    
+                                    break
+                        else:
+                            break
+
+    def _create_testbed_controller(self, guid, data, element_guids, recover):
+        (testbed_id, testbed_version) = data.get_testbed_data(guid)
+        deployment_config = self._deployment_config.get(guid)
+        
+        # deferred import because proxy needs
+        # our class definitions to define proxies
+        import nepi.util.proxy as proxy
+        
+        if deployment_config is None:
+            # need to create one
+            deployment_config = proxy.AccessConfiguration()
+            
+            for (name, value) in data.get_attribute_data(guid):
+                if value is not None and deployment_config.has_attribute(name):
+                    # if any deployment config attribute has a netref, we can't
+                    # create this controller yet
+                    if isinstance(value, basestring) and ATTRIBUTE_PATTERN_BASE.search(value):
+                        # remember to re-issue this one
+                        self._netreffed_testbeds.add(guid)
+                        return
+                    
+                    # copy deployment config attribute
+                    deployment_config.set_attribute_value(name, value)
+            
+            # commit config
+            self._deployment_config[guid] = deployment_config
+        
+        if deployment_config is not None:
+            # force recovery mode 
+            deployment_config.set_attribute_value("recover",recover)
+        
+        testbed = proxy.create_testbed_controller(testbed_id, testbed_version,
+                deployment_config)
+        for (name, value) in data.get_attribute_data(guid):
+            testbed.defer_configure(name, value)
+        self._testbeds[guid] = testbed
+        if guid in self._netreffed_testbeds:
+            self._netreffed_testbeds.remove(guid)
+
+    def _program_testbed_controllers(self, element_guids, data):
+        def resolve_create_netref(data, guid, name, value): 
+            # Try to resolve create-time netrefs, if possible
+            if isinstance(value, basestring) and ATTRIBUTE_PATTERN_BASE.search(value):
+                try:
+                    nuvalue = self.resolve_netref_value(value)
+                except:
+                    # Any trouble means we're not in shape to resolve the netref yet
+                    nuvalue = None
+                if nuvalue is not None:
+                    # Only if we succeed we remove the netref deferral entry
+                    value = nuvalue
+                    data.set_attribute_data(guid, name, value)
+                    if (testbed_guid, guid) in self._netrefs:
+                        self._netrefs[(testbed_guid, guid)].discard(name)
+            return value
 
-    def _program_testbed_instances(self, element_guids, data):
         for guid in element_guids:
             (testbed_guid, factory_id) = data.get_box_data(guid)
-            testbed = self._testbeds[testbed_guid]
-            testbed.defer_create(guid, factory_id)
-            for (name, value) in data.get_attribute_data(guid):
-                testbed.defer_create_set(guid, name, value)
+            testbed = self._testbeds.get(testbed_guid)
+            if testbed is not None:
+                # create
+                testbed.defer_create(guid, factory_id)
+                # set attributes
+                for (name, value) in data.get_attribute_data(guid):
+                    value = resolve_create_netref(data, guid, name, value)
+                    testbed.defer_create_set(guid, name, value)
 
-        for guid in element_guids: 
+        for guid in element_guids:
             (testbed_guid, factory_id) = data.get_box_data(guid)
-            testbed = self._testbeds[testbed_guid]
-            for (connector_type_name, other_guid, other_connector_type_name) \
-                    in data.get_connection_data(guid):
+            testbed = self._testbeds.get(testbed_guid)
+            if testbed is not None:
+                # traces
+                for trace_id in data.get_trace_data(guid):
+                    testbed.defer_add_trace(guid, trace_id)
+                # addresses
+                for (address, netprefix, broadcast) in data.get_address_data(guid):
+                    if address != None:
+                        testbed.defer_add_address(guid, address, netprefix, 
+                                broadcast)
+                # routes
+                for (destination, netprefix, nexthop, metric, device) in \
+                        data.get_route_data(guid):
+                    testbed.defer_add_route(guid, destination, netprefix, nexthop, 
+                            metric, device)
+                # store connections data
+                for (connector_type_name, other_guid, other_connector_type_name) \
+                        in data.get_connection_data(guid):
+                    (other_testbed_guid, other_factory_id) = data.get_box_data(
+                            other_guid)
+                    if testbed_guid == other_testbed_guid:
+                        # each testbed should take care of enforcing internal
+                        # connection simmetry, so each connection is only
+                        # added in one direction
+                        testbed.defer_connect(guid, connector_type_name, 
+                                other_guid, other_connector_type_name)
+
+    def _program_testbed_cross_connections(self, data):
+        data_guids = data.guids
+        for guid in data_guids: 
+            if not data.is_testbed_data(guid):
                 (testbed_guid, factory_id) = data.get_box_data(guid)
-                (other_testbed_guid, other_factory_id) = data.get_box_data(
-                        other_guid)
-                if testbed_guid == other_testbed_guid:
-                    testbed.defer_connect(guid, connector_type_name, other_guid, 
-                        other_connector_type_name)
-                else:
-                    testbed.defer_cross_connect(guid, connector_type_name, other_guid, 
-                        other_testbed_id, other_factory_id, other_connector_type_name)
-            for trace_id in data.get_trace_data(guid):
-                testbed.defer_add_trace(guid, trace_id)
-            for (autoconf, address, netprefix, broadcast) in \
-                    data.get_address_data(guid):
-                if address != None:
-                    testbed.defer_add_address(guid, address, netprefix, broadcast)
-            for (destination, netprefix, nexthop) in data.get_route_data(guid):
-                testbed.defer_add_route(guid, destination, netprefix, nexthop)
+                testbed = self._testbeds.get(testbed_guid)
+                if testbed is not None:
+                    for (connector_type_name, cross_guid, cross_connector_type_name) \
+                            in data.get_connection_data(guid):
+                        (testbed_guid, factory_id) = data.get_box_data(guid)
+                        (cross_testbed_guid, cross_factory_id) = data.get_box_data(
+                                cross_guid)
+                        if testbed_guid != cross_testbed_guid:
+                            cross_testbed = self._testbeds[cross_testbed_guid]
+                            cross_testbed_id = cross_testbed.testbed_id
+                            testbed.defer_cross_connect(guid, connector_type_name, cross_guid, 
+                                    cross_testbed_guid, cross_testbed_id, cross_factory_id, 
+                                    cross_connector_type_name)
+                            # save cross data for later
+                            self._logger.debug("ExperimentController: adding cross_connection data tbd=%d:guid=%d - tbd=%d:guid=%d" % \
+                                    (testbed_guid, guid, cross_testbed_guid, cross_guid))
+                            self._add_crossdata(testbed_guid, guid, cross_testbed_guid,
+                                    cross_guid)
+
+    def _add_crossdata(self, testbed_guid, guid, cross_testbed_guid, cross_guid):
+        if testbed_guid not in self._cross_data:
+            self._cross_data[testbed_guid] = dict()
+        if cross_testbed_guid not in self._cross_data[testbed_guid]:
+            self._cross_data[testbed_guid][cross_testbed_guid] = set()
+        self._cross_data[testbed_guid][cross_testbed_guid].add(cross_guid)
+
+    def _get_cross_data(self, testbed_guid):
+        cross_data = dict()
+        if not testbed_guid in self._cross_data:
+            return cross_data
+
+        # fetch attribute lists in one batch
+        attribute_lists = dict()
+        for cross_testbed_guid, guid_list in \
+                self._cross_data[testbed_guid].iteritems():
+            cross_testbed = self._testbeds[cross_testbed_guid]
+            for cross_guid in guid_list:
+                attribute_lists[(cross_testbed_guid, cross_guid)] = \
+                    cross_testbed.get_attribute_list_deferred(cross_guid)
+
+        # fetch attribute values in another batch
+        for cross_testbed_guid, guid_list in \
+                self._cross_data[testbed_guid].iteritems():
+            cross_data[cross_testbed_guid] = dict()
+            cross_testbed = self._testbeds[cross_testbed_guid]
+            for cross_guid in guid_list:
+                elem_cross_data = dict(
+                    _guid = cross_guid,
+                    _testbed_guid = cross_testbed_guid,
+                    _testbed_id = cross_testbed.testbed_id,
+                    _testbed_version = cross_testbed.testbed_version)
+                cross_data[cross_testbed_guid][cross_guid] = elem_cross_data
+                attribute_list = attribute_lists[(cross_testbed_guid,cross_guid)]
+                for attr_name in attribute_list:
+                    attr_value = cross_testbed.get_deferred(cross_guid, attr_name)
+                    elem_cross_data[attr_name] = attr_value
+        
+        # undefer all values - we'll have to serialize them probably later
+        for cross_testbed_guid, testbed_cross_data in cross_data.iteritems():
+            for cross_guid, elem_cross_data in testbed_cross_data.iteritems():
+                for attr_name, attr_value in elem_cross_data.iteritems():
+                    elem_cross_data[attr_name] = _undefer(attr_value)
+        
+        return cross_data
+
+class ExperimentSuite(object):
+    def __init__(self, experiment_xml, access_config, repetitions = None,
+            duration = None, wait_guids = None):
+        self._experiment_xml = experiment_xml
+        self._access_config = access_config
+        self._controllers = dict()
+        self._access_configs = dict()
+        self._repetitions = 1 if not repetitions else repetitions
+        self._duration = duration
+        self._wait_guids = wait_guids
+        self._current = None
+        self._status = TS.STATUS_ZERO
+        self._thread = None
+
+    def current(self):
+        return self._current
+
+    def status(self):
+        return self._status
+
+    def is_finished(self):
+        return self._status == TS.STATUS_STOPPED
+
+    def get_access_configurations(self):
+        return self._access_configs.values()
+
+    def start(self):
+        self._status  = TS.STATUS_STARTED
+        self._thread = threading.Thread(target = self._run_experiment_suite)
+        self._thread.start()
+
+    def shutdown(self):
+        if self._thread:
+            self._thread.join()
+            self._thread = None
+        for controller in self._controllers.values():
+            controller.shutdown()
+
+    def get_current_access_config(self):
+        return self._access_configs[self._current]
+
+    def _run_experiment_suite(self):
+        for i in xrange(1, self._repetitions):
+            self._current = i
+            self._run_one_experiment()
+        self._status = TS.STATUS_STOPPED
+
+    def _run_one_experiment(self):
+        from nepi.util import proxy
+        access_config = proxy.AccessConfiguration()
+        for attr in self._access_config.attributes:
+            if attr.value:
+                access_config.set_attribute_value(attr.name, attr.value)
+        access_config.set_attribute_value(DC.DEPLOYMENT_MODE, DC.MODE_DAEMON)
+        root_dir = "%s_%d" % (
+                access_config.get_attribute_value(DC.ROOT_DIRECTORY), 
+                self._current)
+        access_config.set_attribute_value(DC.ROOT_DIRECTORY, root_dir)
+        controller = proxy.create_experiment_controller(self._experiment_xml,
+                access_config)
+        self._access_configs[self._current] = access_config
+        self._controllers[self._current] = controller
+        controller.start()
+        started_at = time.time()
+        # wait until all specified guids have finished execution
+        if self._wait_guids:
+            while all(itertools.imap(controller.is_finished, self._wait_guids)):
+                time.sleep(0.5)
+        # wait until the minimum experiment duration time has elapsed 
+        if self._duration:
+            while (time.time() - started_at) < self._duration:
+                time.sleep(0.5)
+        controller.stop()