Updates the graph API to remove any caches before executing the functionality of an API endpoint

scripts/clmc-service/install-clmc-service.sh

@@ -164,3 +164,4 @@ systemctl restart nginx  # nginx is already started on installation, to read the
 
 # move the graph pipeline script
 cp ${REPO_ROOT}/scripts/clmc-service/graph-pipeline.sh /usr/local/bin/
+chmod u+x /usr/local/bin/graph-pipeline.sh
\ No newline at end of file

src/service/clmcservice/graphapi/conftest.py

@@ -203,6 +203,9 @@ def graph_network_topology():
     global links, switches, clusters
 
     graph = Graph(host="localhost", password="admin")
+    graph.node_cache.clear()
+    graph.relationship_cache.clear()
+
     build_network_graph(graph, switches, links, clusters, ues)
 
     yield

src/service/clmcservice/graphapi/views.py

@@ -73,7 +73,7 @@ class GraphAPI(object):
         except AssertionError as e:
             raise HTTPBadRequest("Bad request content: {0}".format(e.args))
 
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])
+        graph = self.get_graph_reference()
         influx_client = InfluxDBClient(host=self.request.registry.settings['influx_host'], port=self.request.registry.settings['influx_port'], timeout=10)
 
         database_name = json_queries["service_function_chain"]
@@ -102,7 +102,7 @@ class GraphAPI(object):
         """
 
         graph_id = self.request.matchdict['graph_id']  # get the UUID of the subgraph from the URL
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])  # connect to the neo4j graph db
+        graph = self.get_graph_reference()
 
         if graph.nodes.match("Reference", uuid=graph_id).first() is None:
             raise HTTPNotFound("No subgraph found associated with the request ID {0}".format(graph_id))
@@ -121,7 +121,7 @@ class GraphAPI(object):
         """
 
         sfc_id = self.request.matchdict['sfc_id']  # get the SFC identifier from the URL
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])  # connect to the neo4j graph db
+        graph = self.get_graph_reference()
 
         # check if this SFC node exists
         sfc_node = graph.nodes.match("ServiceFunctionChain", name=sfc_id).first()
@@ -162,7 +162,7 @@ class GraphAPI(object):
         startpoint_node_label = params["startpoint"]
         endpoint_node_label = params["endpoint"]
 
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])  # connect to the neo4j graph db
+        graph = self.get_graph_reference()
 
         all_nodes = graph.nodes
 
@@ -260,7 +260,7 @@ class GraphAPI(object):
         :return: A JSON response with the number of switches, clusters and ues that were built.
         """
 
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])  # connect to the neo4j graph db
+        graph = self.get_graph_reference()
 
         sdn_controller_ip = self.request.registry.settings['sdn_controller_ip']
         sdn_controller_port = self.request.registry.settings['sdn_controller_port']
@@ -360,7 +360,7 @@ class GraphAPI(object):
         :return: A JSON response with the number of switches, clusters and ues that were deleted.
         """
 
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])  # connect to the neo4j graph db
+        graph = self.get_graph_reference()
 
         deleted_switches, deleted_clusters, deleted_ues = delete_network_graph(graph)
 
@@ -388,7 +388,8 @@ class GraphAPI(object):
             raise HTTPBadRequest("Database for service function chain {0} not found.".format(database_name))
 
         # get the list of UEs from the Neo4j graph - if no UEs are found, the network topology has not been built yet, so return bad request
-        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])
+        graph = self.get_graph_reference()
+
         ue_nodes = graph.nodes.match("UserEquipment")
         ues_list = [ue_node["name"] for ue_node in ue_nodes]
         # return bad request for empty list of UEs
@@ -440,3 +441,19 @@ class GraphAPI(object):
         MonitoringProcess.delete(request_id)
 
         return response
+
+    def get_graph_reference(self):
+        """
+        A utility function to get a Graph DB object reference and clear the cache of py2neo since it might lead to erroneous behaviour
+
+        :return: reference to the graph DB object
+        """
+
+        graph = Graph(host=self.request.registry.settings['neo4j_host'], password=self.request.registry.settings['neo4j_password'])
+
+        # TODO we probably need to remove the caching functionality of py2neo and maintain our own version
+        # NOTE: make sure Py2neo caching is disabled!
+        graph.node_cache.clear()
+        graph.relationship_cache.clear()
+
+        return graph