diff --git a/dmdot b/dmdot
new file mode 100755
index 0000000..2d95e9d
--- /dev/null
+++ b/dmdot
@@ -0,0 +1,49 @@
+#!/usr/bin/python
+
+import os
+import pdb
+import sys
+import json
+
+sys.path.append('.')
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "planetstack.settings")
+
+from django.db.models.fields.related import ForeignKey
+from core.models import *
+
+try:
+	output = sys.args[1]
+except:
+	output = '-json'
+
+g = globals()
+model_classes = []
+class_names = []
+for c in g.values():
+	if type(c)==type(PlCoreBase):
+		model_classes.append(c)
+		class_names.append(c.__name__)
+
+
+if (output=='-dot'):
+	print "digraph plstack {";
+	for c in model_classes:
+		fields = c._meta.fields
+		for f in fields:
+			if type(f)==ForeignKey and f.name.title() in class_names:
+				print '\t"%s"->"%s";'%(c.__name__,f.name.title())
+	print "}\n";
+elif (output=='-json'):
+	d = {}
+	for c in model_classes:
+		fields = c._meta.fields
+		for f in fields:
+			if type(f)==ForeignKey and f.name.title() in class_names:
+				try:
+					d[c.__name__].append(f.name.title())
+				except KeyError:
+					d[c.__name__]=[f.name.title()]
+	print json.dumps(d,indent=4)
+	
+	
diff --git a/planetstack.deps b/planetstack.deps
new file mode 100644
index 0000000..6eae1fc
--- /dev/null
+++ b/planetstack.deps
@@ -0,0 +1,47 @@
+{
+    "Node": [
+        "Site", 
+        "Deployment"
+    ], 
+    "Slice": [
+        "Site"
+    ], 
+    "ReservedResource": [
+        "Sliver"
+    ], 
+    "SliceMembership": [
+        "User", 
+        "Slice", 
+        "Role"
+    ], 
+    "NetworkSlice": [
+        "Network", 
+        "Slice"
+    ], 
+    "Tag": [
+        "Project"
+    ], 
+    "User": [
+        "Site"
+    ], 
+    "SliceTag": [
+        "Slice"
+    ], 
+    "Reservation": [
+        "Slice"
+    ], 
+    "NetworkSliver": [
+        "Network", 
+        "Sliver"
+    ], 
+    "SitePrivilege": [
+        "User", 
+        "Site", 
+        "Role"
+    ], 
+    "Sliver": [
+        "Image", 
+        "Slice", 
+        "Node"
+    ]
+}
diff --git a/planetstack/observer/event_loop.py b/planetstack/observer/event_loop.py
index 4b11504..b565a15 100644
--- a/planetstack/observer/event_loop.py
+++ b/planetstack/observer/event_loop.py
@@ -12,9 +12,13 @@
 from util.logger import Logger, logging, logger
 #from timeout import timeout
 
+debug_mode = False
 
 logger = Logger(logfile='observer.log', level=logging.INFO)
 
+class StepNotReady(Exception):
+	pass
+
 def toposort(g, steps):
 	reverse = {}
 
@@ -54,23 +58,23 @@
 class PlanetStackObserver:
 	sync_steps = ['SyncNetworks','SyncNetworkSlivers','SyncSites','SyncSitePrivileges','SyncSlices','SyncSliceMemberships','SyncSlivers','SyncSliverIps']
 
-    def __init__(self):
-        self.manager = OpenStackManager()
-        # The Condition object that gets signalled by Feefie events
+	def __init__(self):
+		self.manager = OpenStackManager()
+		# The Condition object that gets signalled by Feefie events
 		self.load_sync_steps()
-        self.event_cond = threading.Condition()
+		self.event_cond = threading.Condition()
 		self.load_enacted()
 
-    def wait_for_event(self, timeout):
-        self.event_cond.acquire()
-        self.event_cond.wait(timeout)
-        self.event_cond.release()
-        
-    def wake_up(self):
-        logger.info('Wake up routine called. Event cond %r'%self.event_cond)
-        self.event_cond.acquire()
-        self.event_cond.notify()
-        self.event_cond.release()
+	def wait_for_event(self, timeout):
+		self.event_cond.acquire()
+		self.event_cond.wait(timeout)
+		self.event_cond.release()
+		
+	def wake_up(self):
+		logger.info('Wake up routine called. Event cond %r'%self.event_cond)
+		self.event_cond.acquire()
+		self.event_cond.notify()
+		self.event_cond.release()
 
 	def load_sync_steps(self):
 		dep_path = Config().pl_dependency_path
@@ -100,6 +104,7 @@
 					try:
 						dest = provides_dict[m]
 					except KeyError:
+						pass
 						# no deps, pass
 					step_graph[source]=dest
 					
@@ -121,6 +126,7 @@
 							dest = backend_dict[m]
 						except KeyError:
 							# no deps, pass
+							pass
 						step_graph[source]=dest
 						
 				except KeyError:
@@ -130,32 +136,85 @@
 		dependency_graph = step_graph
 
 		self.ordered_steps = toposort(dependency_graph, steps)
-		
+		self.last_run_times={}
+		for e in self.ordered_steps:
+			self.last_run_times[e.name]=0
 
-    def run(self):
-        if not self.manager.enabled or not self.manager.has_openstack:
-            return
+	def check_duration(self):
+		try:
+			if (duration > S.deadline):
+				logger.info('Sync step %s missed deadline, took %.2f seconds'%(S.name,duration))
+		except AttributeError:
+			# S doesn't have a deadline
+			pass
 
-		
-        while True:
-            try:
-                start_time=time.time()
-                
-                logger.info('Waiting for event')
-                tBeforeWait = time.time()
-                self.wait_for_event(timeout=300)
+	def update_run_time(self, step):
+		self.last_run_times[step.name]=time.time()
+
+	def check_schedule(self, step):
+		time_since_last_run = time.time() - self.last_run_times[step.name]
+		try:
+			if (time_since_last_run < step.requested_interval):
+				raise StepNotReady
+		except AttributeError:
+			logger.info('Step %s does not have requested_interval set'%step.name)
+			raise StepNotReady
+	
+	def check_class_dependency(self, step, failed_steps):
+		for failed_step in failed_steps:
+			if (failed_step in self.dependency_graph[step.name]):
+				raise StepNotReady
+
+	def run(self):
+		if not self.manager.enabled or not self.manager.has_openstack:
+			return
+
+		while True:
+			try:
+				logger.info('Waiting for event')
+				tBeforeWait = time.time()
+				self.wait_for_event(timeout=300)
+				logger.info('Observer woke up')
+
+				# Set of whole steps that failed
+				failed_steps = []
+
+				# Set of individual objects within steps that failed
+				failed_step_objects = []
 
 				for S in self.ordered_steps:
+					start_time=time.time()
+					
 					sync_step = S()
-					sync_step()
+					sync_step.dependencies = self.dependencies[sync_step.name]
+					sync_step.debug_mode = debug_mode
 
-                # Enforce 5 minutes between wakeups
-                tSleep = 300 - (time.time() - tBeforeWait)
-                if tSleep > 0:
-                    logger.info('Sleeping for %d seconds' % tSleep)
-                    time.sleep(tSleep)
+					should_run = False
+					try:
+						# Various checks that decide whether
+						# this step runs or not
+						self.check_class_dependency(sync_step, failed_steps) # dont run Slices if Sites failed
+						self.check_schedule(sync_step) # dont run sync_network_routes if time since last run < 1 hour
+						should_run = True
+					except StepNotReady:
+						logging.info('Step not ready: %s'%sync_step.name)
+						failed_steps.add(sync_step)
+					except:
+						failed_steps.add(sync_step)
 
-                logger.info('Observer woke up')
-            except:
-                logger.log_exc("Exception in observer run loop")
-                traceback.print_exc()
+					if (should_run):
+						try:
+							duration=time.time() - start_time
+
+							# ********* This is the actual sync step
+							failed_objects = sync_step(failed=failed_step_objects)
+
+
+							check_deadline(sync_step, duration)
+							failed_step_objects.extend(failed_objects)
+							self.update_run_time(sync_step)
+						except:
+							failed_steps.add(S)
+			except:
+				logger.log_exc("Exception in observer run loop")
+				traceback.print_exc()
diff --git a/planetstack/observer/openstacksyncstep.py b/planetstack/observer/openstacksyncstep.py
index 7bfe9f4..3ce3c68 100644
--- a/planetstack/observer/openstacksyncstep.py
+++ b/planetstack/observer/openstacksyncstep.py
@@ -10,17 +10,7 @@
 		super(SyncStep,self).__init__(**args)
 		return
 
-	def call(self):
-		pending = self.fetch_pending()
-		failed = []
-		for o in pending:
-			if (not self.depends_on(o, failed)):
-				try:
-					self.sync_record(o)
-					o.enacted = datetime.now() # Is this the same timezone? XXX
-					o.save(update_fields=['enacted'])
-				except:
-					failed.append(o)
+	
 
 
 	def __call__(self):
diff --git a/planetstack/observer/syncstep.py b/planetstack/observer/syncstep.py
index b206106..f3eb4ba 100644
--- a/planetstack/observer/syncstep.py
+++ b/planetstack/observer/syncstep.py
@@ -2,6 +2,9 @@
 import base64
 from planetstack.config import Config
 
+class FailedDependency(Exception):
+	pass
+
 class SyncStep:
 	""" A PlanetStack Sync step. 
 
@@ -24,6 +27,7 @@
 		   		name -- Name of the step
 				provides -- PlanetStack models sync'd by this step
 		"""
+		dependencies = []
 		try:
 			self.soft_deadline = int(self.get_prop('soft_deadline_seconds'))
 		except:
@@ -33,9 +37,26 @@
 
 	def fetch_pending(self):
 		return Sliver.objects.filter(ip=None)
+	
+	def check_dependencies(self, obj):
+		for dep in dependencies:
+			peer_object = getattr(obj, dep.name.lowercase())
+			if (peer_object.pk==dep.pk):
+				raise DependencyFailed
 
-	def call(self):
-		return True
+	def call(self, failed=failed_objects):
+		pending = self.fetch_pending()
+		failed = []
+		for o in pending:
+			if (not self.depends_on(o, failed)):
+				try:
+					check_dependencies(o) # Raises exception if failed					
+					self.sync_record(o)
+					o.enacted = datetime.now() # Is this the same timezone? XXX
+					o.save(update_fields=['enacted'])
+				except:
+					failed.append(o)
+		return failed
 
 	def __call__(self):
 		return self.call()