---------- Forwarded message ---------- From: Guanyao Huang <gyhu...@ucdavis.edu> Date: Wed, Dec 23, 2009 at 3:17 PM Subject: Re: [nox-dev] A general question regarding discovery module To: Martin Casado <cas...@nicira.com>
In verbose model: 00015|openflow|WARN:stream: send error: Broken pipe 00016|routingMR|ERR:Add flow entry to dp:f7cae400012c failed with 32:Broken pipe. 00017|openflow|WARN:stream: receive error: Bad file descriptor 00018|nox|WARN:stream: disconnected (Bad file descriptor) Datapath leave, f7:ca:e4:00:01:2c 00019|bindings_storage|ERR:NDB error on get_locnames_cb (ok if transient): Can't find specified row 00020|nox|ERR:no datapath with id f7cae400012c registered at nox not successfully opf command: routingMR::send_stats_request() 00021|nox|ERR:no datapath with id f7cae400012c registered at nox not successfully opf command: routingMR::send_stats_request() 00022|openflow|WARN:stream: send error: Broken pipe 00023|routingMR|ERR:Add flow entry to dp:f7cae40000c8 failed with 32:Broken pipe. 00024|openflow|WARN:stream: send error: Bad file descriptor Before these warnings, some other warnings show there are Unidirectional links: WARNING: Unidirectional link detected between f7:ca:e4:00:01:2c -- 21 <--> f7:ca:e4:00:00:64 -- 15 WARNING: Unidirectional link detected between f7:ca:e4:00:01:90 -- 26 <--> f7:ca:e4:00:01:2c -- 24 WARNING: Unidirectional link detected between f7:ca:e4:00:01:2c -- 21 <--> f7:ca:e4:00:00:64 -- 15 WARNING: Unidirectional link detected between f7:ca:e4:00:01:90 -- 26 <--> f7:ca:e4:00:01:2c -- 24 On Wed, Dec 23, 2009 at 3:08 PM, Guanyao Huang <gyhu...@ucdavis.edu> wrote: > I forgot to mention: > > Those warnings are the first warnings in my program. After them, it > shows failure to send flow command to the switch that left. If the > discovery module times out first, I guess some warnings will print > out. > > On Wed, Dec 23, 2009 at 2:55 PM, Martin Casado <cas...@nicira.com> wrote: >> What is likely happening is that discovery times out the link, therefore now >> flows are set up to use it forcing all packets to the controller. This >> causes major packet loss (including the uptime echo request) forcing a reset >> of the connection. >> >>> Right, it only times out links if no LLDP is received. I was asking >>> what was the reason for the warning messages above. Seems they are not >>> related with discovery module. >>> >>> On Wed, Dec 23, 2009 at 2:37 PM, kk yap <yap...@gmail.com> wrote: >>> >>>> >>>> Hi Guanyao, >>>> >>>> I am not sure what you are asking but discovery will not disconnected >>>> switches. That can be said with certainty. >>>> >>>> Regards >>>> KK >>>> >>>> 2009/12/23 Guanyao Huang <gyhu...@ucdavis.edu>: >>>> >>>>> >>>>> Some general questions: >>>>> >>>>> Will the datapath actively leave the network if it is burdened? Or >>>>> only link_timeouts at discovery module will make them leave. >>>>> >>>>> My program has following messages: >>>>> 00016|openflow|WARN:stream: send error: Broken pipe >>>>> 00017|routingMR|ERR:Add flow entry to dp:f7cae4000064 failed with >>>>> 32:Broken pipe. >>>>> 00018|openflow|WARN:stream: receive error: Bad file descriptor >>>>> 00019|nox|WARN:stream: disconnected (Bad file descriptor) >>>>> Datapath leave, f7:ca:e4:00:00:64 >>>>> >>>>> What does "Broken pipe" usually imply? I cant find where it is from. >>>>> >>>>> On Tue, Dec 22, 2009 at 10:41 AM, Guanyao Huang <gyhu...@ucdavis.edu> >>>>> wrote: >>>>> >>>>>> >>>>>> But I am now in UCdavis. I will start my intern next quarter.... >>>>>> >>>>>> On Tue, Dec 22, 2009 at 5:18 AM, Rob Sherwood >>>>>> <rob.sherw...@stanford.edu> wrote: >>>>>> >>>>>>> >>>>>>> Hi Guanyao, >>>>>>> >>>>>>> I'm going to be in the lab today ... let's try to find some time to >>>>>>> talk about this. >>>>>>> >>>>>>> - Rob >>>>>>> . >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Tue, Dec 22, 2009 at 5:17 AM, Rob Sherwood >>>>>>> <rob.sherw...@stanford.edu> wrote: >>>>>>> >>>>>>>> >>>>>>>> On Mon, Dec 21, 2009 at 12:47 PM, Martin Casado <cas...@nicira.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> >>>>>>>>> I agree that if the problem is timeout due to loss from overload, >>>>>>>>> then the >>>>>>>>> only solution is prioritization. >>>>>>>>> >>>>>>>> >>>>>>>> In general yes, but the current discovery algorithm is fairly >>>>>>>> brittle. >>>>>>>> With a large number of ports (48) on a hardware switch, even a small >>>>>>>> amount of packet loss it can falsely report down links. Part of the >>>>>>>> goal of the rewrite is to address this issue. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> Question for the slicing folks, does slicing extend to the control >>>>>>>>> channel >>>>>>>>> (packets set to the controller?) >>>>>>>>> >>>>>>>> >>>>>>>> In addition to what Yiannis said (short story == "not yet"), Jean >>>>>>>> from >>>>>>>> HP developed a "rate limiter" openflow action as a vendor extension >>>>>>>> that can affect control and data traffic, so that could be used here. >>>>>>>> I think this is a useful primitive and something I'm hoping will >>>>>>>> making it into a future release of openflow (1.1?). >>>>>>>> >>>>>>>> - Rob >>>>>>>> . >>>>>>>> >>>>>>>> >>>>> >>>>> _______________________________________________ >>>>> nox-dev mailing list >>>>> nox-dev@noxrepo.org >>>>> http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org >>>>> >>>>> >>> >>> _______________________________________________ >>> nox-dev mailing list >>> nox-dev@noxrepo.org >>> http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org >>> >> >> > _______________________________________________ nox-dev mailing list nox-dev@noxrepo.org http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org
