[pox-dev] Changing the POX component without restarting POX controller
Hi, I am soory if this is a stupid question, but I am new to POX and even though i searched in internet i could not find an answer.. I am using two component files : l2_multi.py component which will send traffic using shortest path.. and l2_multi_edited.py which will send traffic using longest path.. I create a topoligy in mininet and start the POX with l2_multi.py component which will send traffic using shortest path.. after sometime I want to change the componet to l2_multi_edited.py without restarting POX, so that traffic will be send with longest path.. how can I do this ? Please be kind enough to help me Best Regards, Windhya Rankothge
Re: [pox-dev] Changing the POX component without restarting POX controller
Sorry trouble you again Murphy.. Is there any way that I can trace the packet, so that I can check the correctness of my algorithms ? I tried traceroute, but looks like its not working as expected in Mininet On Wed, May 29, 2013 at 2:13 PM, Windhya Rankothge windys...@gmail.comwrote: Thanks Murphy.. It worked correctly.. On Wed, May 29, 2013 at 12:52 PM, Murphy McCauley murphy.mccau...@gmail.com wrote: I'd say the right way to do it is to remove the event listeners set by one component, and then set them up using the other. l2_multi wasn't really written with this in mind so it'd take a bit of tweaking to make it happen. If you were really inclined to do so, I think the easiest way would be to add a boolean enable/disable flag to the l2_multi class and to your version of it. Then have an if statement in l2_multi._handle_ConnectionUp (and your own class's version) that uses the flag to decide whether it should actually call sw.connect(). When you want to switch between components, toggle the enabled flags, then iterate through all active connections, calling disconnect() on the switches of the old component and connect() on the switches of the new component. I think there may be a far, far easier way to go about this, though. It seems like the only thing you should need to change is _get_path() or _get_raw_path() or _calc_paths(). I'd just swap the function at runtime. For example, if you put a modified _get_path() in ext/longestpath.py, you could do something like... ./pox.py forwarding.l2_multi openflow.discovery py This will load up l2_multi and then give a Python interpreter. You can swap the functions from the interpreter... POX import pox.forwarding.l2_multi as l2m POX shortest = l2m._get_path POX import ext.longestpath POX l2m._get_path = ext.longestpath._get_path You can switch back to shortest again by doing: POX l2m._get_path = shortest When you switch, you'll have to wait for existing flows to time out, or send a flow_mod to each connection to delete them (iterate over core.openflow.connections). You might want to wrap that and the other commands above into a quick little toggle function, which you could then add to the interactive prompt. The component would looks something like: import pox.forwarding.l2_multi as l2m _orig_get_path = l2m._get_path def _my_get_path (...): ... Your longest path code here ... def toggle (): if l2m._get_path is _orig_get_path: l2m._get_path = _my_get_path else: l2m._get_path = _orig_get_path def launch (): core.Interactive.variables['toggle'] = toggle Then you can just do toggle() from the POX prompt to switch. Hope that helps. (Excuse bugs in the above code; none of it is tested.) -- Murphy On May 29, 2013, at 3:13 AM, Windhya Rankothge wrote: Hi, I am soory if this is a stupid question, but I am new to POX and even though i searched in internet i could not find an answer.. I am using two component files : l2_multi.py component which will send traffic using shortest path.. and l2_multi_edited.py which will send traffic using longest path.. I create a topoligy in mininet and start the POX with l2_multi.py component which will send traffic using shortest path.. after sometime I want to change the componet to l2_multi_edited.py without restarting POX, so that traffic will be send with longest path.. how can I do this ? Please be kind enough to help me Best Regards, Windhya Rankothge -- Best Regards, Windhya Rankothge. (WINDY) -- Best Regards, Windhya Rankothge. (WINDY)
Re: [pox-dev] Changing the POX component without restarting POX controller
traceroute works via expiring TTLs, which won't happen in OpenFlow switches without some extra work. I don't know of a better way than just running a bunch of tcpdump/wireshark instances on all the intermediate switches. -- Murphy On May 29, 2013, at 7:25 AM, Windhya Rankothge wrote: Sorry trouble you again Murphy.. Is there any way that I can trace the packet, so that I can check the correctness of my algorithms ? I tried traceroute, but looks like its not working as expected in Mininet On Wed, May 29, 2013 at 2:13 PM, Windhya Rankothge windys...@gmail.com wrote: Thanks Murphy.. It worked correctly.. On Wed, May 29, 2013 at 12:52 PM, Murphy McCauley murphy.mccau...@gmail.com wrote: I'd say the right way to do it is to remove the event listeners set by one component, and then set them up using the other. l2_multi wasn't really written with this in mind so it'd take a bit of tweaking to make it happen. If you were really inclined to do so, I think the easiest way would be to add a boolean enable/disable flag to the l2_multi class and to your version of it. Then have an if statement in l2_multi._handle_ConnectionUp (and your own class's version) that uses the flag to decide whether it should actually call sw.connect(). When you want to switch between components, toggle the enabled flags, then iterate through all active connections, calling disconnect() on the switches of the old component and connect() on the switches of the new component. I think there may be a far, far easier way to go about this, though. It seems like the only thing you should need to change is _get_path() or _get_raw_path() or _calc_paths(). I'd just swap the function at runtime. For example, if you put a modified _get_path() in ext/longestpath.py, you could do something like... ./pox.py forwarding.l2_multi openflow.discovery py This will load up l2_multi and then give a Python interpreter. You can swap the functions from the interpreter... POX import pox.forwarding.l2_multi as l2m POX shortest = l2m._get_path POX import ext.longestpath POX l2m._get_path = ext.longestpath._get_path You can switch back to shortest again by doing: POX l2m._get_path = shortest When you switch, you'll have to wait for existing flows to time out, or send a flow_mod to each connection to delete them (iterate over core.openflow.connections). You might want to wrap that and the other commands above into a quick little toggle function, which you could then add to the interactive prompt. The component would looks something like: import pox.forwarding.l2_multi as l2m _orig_get_path = l2m._get_path def _my_get_path (...): ... Your longest path code here ... def toggle (): if l2m._get_path is _orig_get_path: l2m._get_path = _my_get_path else: l2m._get_path = _orig_get_path def launch (): core.Interactive.variables['toggle'] = toggle Then you can just do toggle() from the POX prompt to switch. Hope that helps. (Excuse bugs in the above code; none of it is tested.) -- Murphy On May 29, 2013, at 3:13 AM, Windhya Rankothge wrote: Hi, I am soory if this is a stupid question, but I am new to POX and even though i searched in internet i could not find an answer.. I am using two component files : l2_multi.py component which will send traffic using shortest path.. and l2_multi_edited.py which will send traffic using longest path.. I create a topoligy in mininet and start the POX with l2_multi.py component which will send traffic using shortest path.. after sometime I want to change the componet to l2_multi_edited.py without restarting POX, so that traffic will be send with longest path.. how can I do this ? Please be kind enough to help me Best Regards, Windhya Rankothge -- Best Regards, Windhya Rankothge. (WINDY) -- Best Regards, Windhya Rankothge. (WINDY)
