calling base class method fetches no results
Dave Angel
davea at davea.name
Sat May 9 07:36:43 EDT 2015
On 05/09/2015 03:59 AM, david jhon wrote:
> Hi, I am sorry for sending in five attachments, I cloned the code from here
> <https://bitbucket.org/msharif/hedera/src>: Let me explain it here:
>
Please don't top-post. Your earlier problem description, which I could
make no sense of, is now located after your later "clarification".
Thanks for eliminating the attachments. Many cannot see them. And for
extracting only part of the code into the message. It's still too much
for me, but others may manage it okay. To me, it seems likely that most
of that code will not have any part in the problem you're describing.
And in some places you have code that's missing its context.
Now, eliminate the pieces of code that are irrelevant to your question,
and state the problem in terms that make sense. Somebody is
instantiating an object. Exactly which class is being used for that?
Somebody else is calling a particular method (be specific, rather than
just saying "some method"), and it's giving the wrong results. And
apparently, those wrong results depend on which source file something
happens in.
> Routing Base class defined in DCRouting.py:
>
> import logging
> from copy import copy
>
> class Routing(object):
> '''Base class for data center network routing.
>
> Routing engines must implement the get_route() method.
> '''
>
> def __init__(self, topo):
> '''Create Routing object.
>
> @param topo Topo object from Net parent
> '''
> self.topo = topo
>
> def get_route(self, src, dst, hash_):
> '''Return flow path.
>
> @param src source host
> @param dst destination host
> @param hash_ hash value
>
> @return flow_path list of DPIDs to traverse (including hosts)
> '''
> raise NotImplementedError
>
> def routes(self, src, dst):
> ''' Return list of paths
>
> Only works for Fat-Tree topology
>
> @ param src source host
> @ param dst destination host
>
> @ return list of DPIDs (including inputs)
> '''
>
> complete_paths = [] # List of complete dpid routes
>
> src_paths = { src : [[src]] }
> dst_paths = { dst : [[dst]] }
>
> dst_layer = self.topo.layer(dst)
> src_layer = self.topo.layer(src)
>
> lower_layer = src_layer
> if dst_layer > src_layer:
> lower_layer = dst_layer
>
>
> for front_layer in range(lower_layer-1, -1, -1):
> if src_layer > front_layer:
> # expand src frontier
> new_src_paths = {}
> for node in sorted(src_paths):
> path_list = src_paths[node]
> for path in path_list:
> last_node = path[-1]
> for frontier_node in
> self.topo.upper_nodes(last_node):
> new_src_paths[frontier_node] = [path +
> [frontier_node]]
>
> if frontier_node in dst_paths:
> dst_path_list = dst_paths[frontier_node]
> for dst_path in dst_path_list:
> dst_path_copy = copy ( dst_path )
> dst_path_copy.reverse()
> complete_paths.append( path +
> dst_path_copy)
> src_paths = new_src_paths
>
> if dst_layer > front_layer:
> # expand dst frontier
> new_dst_paths = {}
> for node in sorted(dst_paths):
> path_list = dst_paths[node]
> for path in path_list:
> last_node = path[-1]
> for frontier_node in
> self.topo.upper_nodes(last_node):
> new_dst_paths[frontier_node] = [ path +
> [frontier_node]]
>
> if frontier_node in src_paths:
> src_path_list = src_paths[frontier_node]
> dst_path_copy = copy( path )
> dst_path_copy.reverse()
> for src_path in src_path_list:
> complete_paths.append( src_path +
> dst_path_copy)
>
> dst_paths = new_dst_paths
>
> if complete_paths:
> return complete_paths
> class HashedRouting(Routing):
> ''' Hashed routing '''
>
> def __init__(self, topo):
> self.topo = topo
>
> def get_route(self, src, dst, hash_):
> ''' Return flow path. '''
>
> if src == dst:
> return [src]
>
> paths = self.routes(src,dst)
> if paths:
> #print 'hash_:', hash_
> choice = hash_ % len(paths)
> #print 'choice:', choice
> path = sorted(paths)[choice]
> #print 'path:', path
> return path
>
> ============>
> Instantiated in util.py:
>
> from DCTopo import FatTreeTopo
> from mininet.util import makeNumeric
> from DCRouting import HashedRouting, Routing
>
> TOPOS = {'ft': FatTreeTopo}
> ROUTING = {'ECMP' : HashedRouting}
>
>
> def buildTopo(topo):
> topo_name, topo_param = topo.split( ',' )
> return TOPOS[topo_name](makeNumeric(topo_param))
>
>
> def getRouting(routing, topo):
> return ROUTING[routing](topo)
A comment on that last line that says it instantiates the child class
would have been very helpful.
But even though I can now search for calls to that function, I still
cannot make sense out of that context, either.
>
> ============================> utilized in HController. py:
> A Piece of code which works with self.r.routes() method:
> Following list of methods are defined in HController.py
>
> def _ecmp_hash(self, packet):
> ''' Return an ECMP-style 5-tuple hash for TCP/IP packets, otherwise
> 0.
> RFC2992 '''
> hash_input = [0] * 5
> if isinstance(packet.next, ipv4):
> ip = packet.next
> hash_input[0] = ip.srcip.toUnsigned()
> hash_input[1] = ip.dstip.toUnsigned()
> hash_input[2] = ip.protocol
> if isinstance(ip.next, tcp) or isinstance(ip.next, udp):
> l4 = ip.next
> hash_input[3] = l4.srcport
> hash_input[4] = l4.dstport
> return crc32(pack('LLHHH', *hash_input))
> return 0
>
> def _install_reactive_path(self, event, out_dpid, final_out_port,
> packet):
> ''' Install entries on route between two switches. '''
> in_name = self.t.node_gen(dpid = event.dpid).name_str()
> out_name = self.t.node_gen(dpid = out_dpid).name_str()
> hash_ = self._ecmp_hash(packet)
> paths = self.r.routes(src_name, dst_name)
> if paths == None:
> print "PATH is None :("
> return
> route = self.r.get_route(in_name, out_name, hash_)
> print "Route:",route
> print '-'*80
> if route == None:
> print None, "route between", in_name, "and", out_name
> return
>
> match = of.ofp_match.from_packet(packet)
>
> for i, node in enumerate(route):
> node_dpid = self.t.node_gen(name = node).dpid
> if i < len(route) - 1:
> next_node = route[i + 1]
> out_port, next_in_port = self.t.port(node, next_node)
> else:
> out_port = final_out_port
> self.switches[node_dpid].install(out_port, match, idle_timeout
> = 10)
>
> if isinstance(packet.next, of.ipv4) and
> isinstance(packet.next.next, of.tcp):
> self.matchDict[(packet.next.srcip, packet.next.dstip,
> packet.next.next.srcport, packet.next.next.dstport)] = (route, match)
>
> def _handle_PacketIn(self, event):
> if not self.all_switches_up:
> #log.info("Saw PacketIn before all switches were up -
> ignoring." )
> return
>
> packet = event.parsed
> dpid = event.dpid
> in_port = event.port
>
> # Learn MAC address of the sender on every packet-in.
> self.macTable[packet.src] = (dpid, in_port)
> sw_name = self.t.node_gen(dpid = dpid).name_str()
> #print "Sw:", sw_name, packet.src, packet.dst,"port", in_port,
> packet.dst.isMulticast(),"macTable", packet.dst in self.macTable
> #print '-'*80
>
> # Insert flow, deliver packet directly to destination.
>
> if packet.dst in self.macTable:
> out_dpid, out_port = self.macTable[packet.dst]
> self._install_reactive_path(event, out_dpid, out_port, packet)
>
> self.switches[out_dpid].send_packet_data(out_port, event.data)
>
> else:
> self._flood(event)
>
> ===================> code snippet which returns 'None' number of paths.
> def _GlobalFirstFit(self,flow):
> '''do the Hedera global first fit here'''
> src_name = self.t.node_gen(dpid = flow['src']).name_str()
> dst_name = self.t.node_gen(dpid = flow['dst']).name_str()
> print 'Global Fisrt Fit for the elephant flow from ',src_name,'to',
> dst_name
> paths = self.r.routes(src_name,dst_name)
> print 'all routes found for the big flow:\n',paths
> GFF_route = None
> if paths == None:
> return
> else:
> for path in paths:
> fitCheck = True
>
> for i in range(1,len(path)):
> fitCheck = False
> if self.bwReservation.has_key(path[i-1]) and
> self.bwReservation[path[i-1]].has_key(path[i]):
> if
> self.bwReservation[path[i-1]][path[i]]['reserveDemand'] + flow['demand'] >
> 1 :
> break
> else:
>
> #self.bwReservation[path[i-1]][path[i]]['reserveDemand'] += flow['demand']
> fitCheck = True
> else:
> self.bwReservation[path[i-1]]={}
>
> self.bwReservation[path[i-1]][path[i]]={'reserveDemand':0}
> fitCheck = True
> if fitCheck == True:
> for i in range(1,len(path)):
> self.bwReservation[path[i-1]][path[i]]['reserveDemand']
> += flow['demand']
> GFF_route = path
> print "GFF route found:", path
> break
> if GFF_route != None:
> """install new GFF_path between source and destintaion"""
> self. _install_GFF_path(GFF_route,flow['match'])
>
> def launch(topo = None, routing = None, bw = None ):
> #print topo
> if not topo:
> raise Exception ("Please specify the topology")
> else:
> t = buildTopo(topo)
>
> r = getRouting(routing, t)
> if bw == None:
> bw = 10.0 #Mb/s
> bw = float(bw/1000) #Gb/s
> else:
> bw = float(bw)/1000
> core.registerNew(HController, t, r, bw)
> log.info("** HController is running
>
> I am really sorry for any inconvenience caused. I, ve tried to make it a
> bit clear here. I am not even able to debug the code by setting a python
> debugging point pdb. I need help from you guys. Thanks a lot again for your
> time and help.
>
> Best Regards,
> David
>
>
> On Sat, May 9, 2015 at 12:07 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>
> wrote:
>
>> On 09/05/2015 07:41, david jhon wrote:
>>
>>> Hello everyone,
>>>
>>> I am new to python and trying to run an example code from mininet tests.
>>> Basically, I am trying to call a method in Hcontroller.py from base class
>>> Routing defined in DCRouting.py which runs and fetches all the required
>>> results in install_reactive_path() method, but it returns None when it is
>>> called from _GlobalFirstFit. I hope someone here could help me fix this
>>> bug..
>>>
>>> I am attaching all the three files(DCRouting.py, HController.py, util.py)
>>> to have a look into. Thanks in advance for your time, help or suggestion.
>>> Thanks a lot!
>>>
>>> kind regards,
>>> David
>>>
>>>
>> I'm sorry but I'm not wading through nearly 30kb of code in five
>> attachments. Please see http://sscce.org/ for how to put your question
>> so you're more likely to get answers.
>>
>> --
>> My fellow Pythonistas, ask not what our language can do for you, ask
>> what you can do for our language.
>>
>> Mark Lawrence
>>
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>
>
>
--
DaveA
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