UPD: Sorry, I forget to add dump from user space that shows that part of packets are missed: sudo ovs-ofctl dump-aggregate br0 NXST_AGGREGATE reply (xid=0x4): packet_count=380 byte_count=20736 flow_count=500
On 18 November 2013 15:52, Anton Matsiuk <anton.mats...@gmail.com> wrote: > Hello all, > > I test the Open vSwitch in the following scheme: I use 2 hosts directly > connected to OSV and external OpenFlow Controller. Host1 generates UDP > datagrams with sequential ports towards Host2, Host 2 listens for these > UDP datagrams. In responce to every UDP datagram OVS generates Packet_In > and Controller sends Flow_Mod with granularity up to L4 (so for every pair > of UDP port numbers it installs separate rule). I send bunch of UDP > datagrams from Host1 and calculate how many of them arrived to Host2. > > Starting some number of packets ( > 300) packet drops are observed. For > instance, if I generate 500 UDP packets in 120 ms only around 380 of them > arrive to Host2. > ovs-dpctl show -s command shows , that I have 500 flows installed 500 > packets on ingress interface (port 1) of OVS and 380 on egress (port 2). > So, it seems like OVS drop packets starting with some load threshold: > > lookups: hit:0 missed:500 lost:0 > flows: 500 > port 1: eth2 > RX packets:500 errors:0 dropped:0 overruns:0 frame:0 > TX packets:12 errors:0 dropped:0 aborted:0 carrier:0 > collisions:0 > port 2: eth3 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:380 errors:0 dropped:0 aborted:0 carrier:0 > collisions:0 > > ovs-dpctl dump-flows br0 shows all the flows installed but no one with > matched packets: > > in_port(1),eth(src=00:00:00:00:00:01,dst=00:00:00:00:00:02),eth_type(0x8100),vlan(vid=10,pcp=3),encap(eth_type(0x0800),ipv4(src=10.0.0.1,dst=10.0.0.2,proto=17,tos=0,ttl=64,frag=no),udp(src=52363,dst=50335)), > packets:0, bytes:0, used:never, > actions:userspace(pid=4294962855,slow_path(controller)) > > I tried both with detached controller and running in the same machine as > OVS (I use out-of-band option for controller and disable-in-band=true) > > Also I tried to replace Flow_Mods with Packet_Out messages for every > ingress UDP datagram (identifying by buffer_id) but I experienced the same > drops. I tested it on different machines (in Mininet and with separated > real hosts) > > I suspect that such behavior is caused by > actions:userspace(pid=4294962855,slow_path(controller)) but how can I > verify where drops are occurred? is there possibility to debug internal > queues or buffers? > > And how could I fix such drops? Should I implement some advances QoS > policies in OVS in this case? > > -- > > Best regards, > Anton Matsiuk > -- Best regards, Anton Matsiuk
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