Hi Dumitru, are you talking about any specific _mising_ patch?
Regards, Vladislav Odintsov > On 16 Sep 2021, at 19:09, Dumitru Ceara <dce...@redhat.com> wrote: > > On 9/16/21 4:18 PM, Vladislav Odintsov wrote: >> Sorry, by OOT I meant non-inbox kmod. >> I’ve tried to use inbox kernel module (from kernel package) and problem >> resolved. >> >> Regards, >> Vladislav Odintsov >> >>> On 16 Sep 2021, at 17:17, Vladislav Odintsov <odiv...@gmail.com> wrote: >>> >>> Hi Dumitru, >>> >>> I’ve tried to exclude OOT OVS kernel module. >>> With OVN 20.06.3 + OVS 2.13.4 the problem solved. >>> >>> Could you please try with OOT kmod? For me it looks like a bug in OOT OVS >>> kernel module code. > > You're right, this seems to be a missing patch in the OOT openvswitch > module. I could replicate the problem you reported with the OOT module. > > Regards, > Dumitru > >>> >>> Thanks. >>> >>> Regards, >>> Vladislav Odintsov >>> >>>> On 16 Sep 2021, at 11:02, Dumitru Ceara <dce...@redhat.com >>>> <mailto:dce...@redhat.com> <mailto:dce...@redhat.com >>>> <mailto:dce...@redhat.com>>> wrote: >>>> >>>> On 9/16/21 2:50 AM, Vladislav Odintsov wrote: >>>>> Hi Dumitru, >>>>> >>>>> thanks for your reply. >>>>> >>>>> Regards, >>>>> Vladislav Odintsov >>>>> >>>>>> On 15 Sep 2021, at 11:24, Dumitru Ceara <dce...@redhat.com> wrote: >>>>>> >>>>>> Hi Vladislav, >>>>>> >>>>>> On 9/13/21 6:14 PM, Vladislav Odintsov wrote: >>>>>>> Hi Numan, >>>>>>> >>>>>>> I’ve checked with OVS 2.16.0 and OVN master. The problem persists. >>>>>>> Symptoms are the same. >>>>>>> >>>>>>> # grep ct_zero_snat /var/log/openvswitch/ovs-vswitchd.log >>>>>>> 2021-09-13T16:10:01.792Z|00019|ofproto_dpif|INFO|system@ovs-system: >>>>>>> Datapath supports ct_zero_snat >>>>>> >>>>>> This shouldn't be related to the problem we fixed with ct_zero_snat. >>>>>> >>>>>>> >>>>>>> Regards, >>>>>>> Vladislav Odintsov >>>>>>> >>>>>>>> On 13 Sep 2021, at 17:54, Numan Siddique <num...@ovn.org> wrote: >>>>>>>> >>>>>>>> On Mon, Sep 13, 2021 at 8:10 AM Vladislav Odintsov <odiv...@gmail.com >>>>>>>> <mailto:odiv...@gmail.com>> wrote: >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> we’ve encountered a next problem with stateful ACLs. >>>>>>>>> >>>>>>>>> Suppose, we have one logical switch (ls1) and attached to it a VIF >>>>>>>>> type logical ports (lsp1, lsp2). >>>>>>>>> Each logical port has a linux VM besides it. >>>>>>>>> >>>>>>>>> Logical ports reside in port group (pg1) and two ACLs are created >>>>>>>>> within this PG: >>>>>>>>> to-lport outport == @pg1 && ip4 && ip4.dst == 0.0.0.0/0 allow-related >>>>>>>>> from-lport outport == @pg1 && ip4 && ip4.src == 0.0.0.0/0 >>>>>>>>> allow-related >>>>>>>>> >>>>>>>>> When we have a high-connection rate service between VMs, the tcp >>>>>>>>> source/dest ports may be reused before the connection is deleted from >>>>>>>>> LSP’s-related conntrack zones on the host. >>>>>>>>> Let’s use curl with passing --local-port argument to have each time >>>>>>>>> same source port. >>>>>>>>> >>>>>>>>> Run it from VM to another VM (172.31.0.18 -> 172.31.0.17): >>>>>>>>> curl --local-port 44444 http://172.31.0.17/ >>>>>>>>> >>>>>>>>> Check connections in client’s and server’s vif zones (client - >>>>>>>>> zone=20, server - zone=1): >>>>>>>>> run while true script to check connections state per-second, while >>>>>>>>> running new connection with same source/dest 5-tuple: >>>>>>>>> >>>>>>>>> while true; do date; grep -e 'zone=1 ' -e zone=20 >>>>>>>>> /proc/net/nf_conntrack; sleep 0.2; done >>>>>>>>> >>>>>>>>> Right after we’ve succesfully run curl, the connection is getting >>>>>>>>> time-closed and next time-wait states: >>>>>>>>> >>>>>>>>> Mon Sep 13 14:34:39 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 59 CLOSE_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=1 use=2 >>>>>>>>> ipv4 2 tcp 6 59 CLOSE_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=20 use=2 >>>>>>>>> Mon Sep 13 14:34:39 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 119 TIME_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=1 use=2 >>>>>>>>> ipv4 2 tcp 6 119 TIME_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=20 use=2 >>>>>>>>> >>>>>>>>> And it remains in time-wait state for nf_conntrack_time_wait_timeout >>>>>>>>> (120 seconds for centos 7). >>>>>>>>> >>>>>>>>> Everything is okay for now. >>>>>>>>> While we have installed connections in TW state in zone 1 and 20, >>>>>>>>> lets run this curl (source port 44444) again: >>>>>>>>> 1st SYN packet is lost. It didn’t get to destination VM. In conntrack >>>>>>>>> we have: >>>>>>>>> >>>>>>>>> Mon Sep 13 14:34:41 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 118 TIME_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=1 use=2 >>>>>>>>> >>>>>>>>> We see that TW connection was dropped in source vif’s zone (20). >>>>>>>>> >>>>>>>>> Next, after one second TCP sends retry and connection in destination >>>>>>>>> (server’s) zone is dropped and a new connection is created in source >>>>>>>>> zone (client’s): >>>>>>>>> >>>>>>>>> Mon Sep 13 14:34:41 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 120 SYN_SENT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 [UNREPLIED] src=172.31.0.17 dst=172.31.0.18 >>>>>>>>> sport=80 dport=44444 mark=0 zone=20 use=2 >>>>>>>>> >>>>>>>>> Server VM still didn’t get this SYN packet. It got dropped. >>>>>>>>> >>>>>>>>> Then, after 2 seconds TCP sends retry again and connection is working >>>>>>>>> well: >>>>>>>>> >>>>>>>>> Mon Sep 13 14:34:44 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 59 CLOSE_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=1 use=2 >>>>>>>>> ipv4 2 tcp 6 59 CLOSE_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=20 use=2 >>>>>>>>> Mon Sep 13 14:34:44 MSK 2021 >>>>>>>>> ipv4 2 tcp 6 119 TIME_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=1 use=2 >>>>>>>>> ipv4 2 tcp 6 119 TIME_WAIT src=172.31.0.18 dst=172.31.0.17 >>>>>>>>> sport=44444 dport=80 src=172.31.0.17 dst=172.31.0.18 sport=80 >>>>>>>>> dport=44444 [ASSURED] mark=0 zone=20 use=2 >>>>>>>>> >>>>>>>>> I guess, that it could happen: >>>>>>>>> 1. Run curl with an empty conntrack zones. Everything is good, we’ve >>>>>>>>> got http response, closed the connection. There’s one TW entry in >>>>>>>>> client’s and one in server’s zonntrack zones. >>>>>>>>> 2. Run curl with same source port within >>>>>>>>> nf_conntrack_time_wait_timeout seconds. >>>>>>>>> 2.1. OVS gets packet from VM, sends it to client’s conntrack zone=20. >>>>>>>>> It matches pre-existed conntrack entry in tw state from previous curl >>>>>>>>> run. TW connection in conntrack is deleted. A copy of a packet is >>>>>>>>> returned to OVS and recirculated packet has ct.inv (?) and !ct.trk >>>>>>>>> states and got dropped (I’m NOT sure, it’s just an assumption!) >>>>>>>>> 3. After one second client VM resends TCP SYN. >>>>>>>>> 3.1. OVS gets packet, sends through client’s conntrack zone=20, a new >>>>>>>>> connection is added, packet has ct.trk and ct.new states set. Packet >>>>>>>>> goes to recirculation. >>>>>>>>> 3.2. OVS sends packet to server’s conntrack zone=1. It matches >>>>>>>>> pre-existed conntrack entry in tw state from previous run. Conntrack >>>>>>>>> removes this entry. Packet is returned to OVS with ct.inv (?) and >>>>>>>>> !ct.trk. Packet got dropped. >>>>>>>>> 4. Client’s VM again sends TCP SYN after 2 more seconds left. >>>>>>>>> 4.1 OVS gets packet from client’s VIF, sends to client’s conntrack >>>>>>>>> zone=20, it matches pre-existed SYN_SENT conntrack entry state, >>>>>>>>> packets is returned to OVS with ct.new, ct.trk flags set. >>>>>>>> >>>>>>>> >>>>>>>>> 4.2 OVS sends packet to server’s conntrack zone=1. Conntrack table >>>>>>>>> for zone=1 is empty, it adds new entry, returns packet to OVS with >>>>>>>>> ct.trk and ct.new flags set. >>>>>>>>> 4.3 OVS sends packet to server’s VIF, next traffic operates normally. >>>>>>>>> >>>>>>>>> So, with such behaviour connection establishment sometimes takes up >>>>>>>>> to three seconds (2 TCP SYN retries) and makes troubles in overlay >>>>>>>>> services. (Application timeouts and service outages). >>>>>>>>> >>>>>>>>> I’ve checked how conntrack works inside VMs with such traffic and it >>>>>>>>> looks like if conntrack gets a packet within a TW connection it >>>>>>>>> recreates a new conntrack entry. No tuning inside VMs was performed. >>>>>>>>> As a server I used apache with default config from CentOS >>>>>>>>> distribution. >>>>>> >>>>>> I don't have a centos 7 at hand but I do have a rhel 7 >>>>>> (3.10.0-1160.36.2.el7.x86_64) and I didn't manage to hit the issue you >>>>>> reported here (using OVS and OVN upstream master). The SYN matching the >>>>>> conntrack entry in state TIME_WAIT moves the entry to NEW and seems to >>>>>> be forwarded just fine, the session afterwards go to ESTABLISHED. >>>>>> >>>>>> Wed Sep 15 04:18:35 AM EDT 2021 >>>>>> conntrack v1.4.5 (conntrack-tools): 7 flow entries have been shown. >>>>>> tcp 6 431930 ESTABLISHED src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=6 use=1 >>>>>> tcp 6 431930 ESTABLISHED src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=3 use=1 >>>>>> -- >>>>>> Wed Sep 15 04:18:36 AM EDT 2021 >>>>>> conntrack v1.4.5 (conntrack-tools): 7 flow entries have been shown. >>>>>> tcp 6 119 TIME_WAIT src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=6 use=1 >>>>>> tcp 6 119 TIME_WAIT src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=3 use=1 >>>>>> -- >>>>>> Wed Sep 15 04:18:38 AM EDT 2021 >>>>>> conntrack v1.4.5 (conntrack-tools): 7 flow entries have been shown. >>>>>> tcp 6 431999 ESTABLISHED src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=6 use=1 >>>>>> tcp 6 431999 ESTABLISHED src=42.42.42.2 dst=42.42.42.3 sport=4141 >>>>>> dport=4242 src=42.42.42.3 dst=42.42.42.2 sport=4242 dport=4141 [ASSURED] >>>>>> mark=0 secctx=system_u:object_r:unlabeled_t:s0 zone=3 use=1 >>>>>> -- >>>>>> >>>>>> DP flows just after the second session is initiated also seem to confirm >>>>>> that everything is fine: >>>>>> >>>>>> # ovs-appctl dpctl/dump-flows | grep -oE "ct_state(.*),ct_label" >>>>>> ct_state(+new-est-rel-rpl-inv+trk),ct_label >>>>>> ct_state(-new+est-rel-rpl-inv+trk),ct_label >>>>>> ct_state(-new+est-rel+rpl-inv+trk),ct_label >>>>>> ct_state(+new-est-rel-rpl-inv+trk),ct_label >>>>>> ct_state(-new+est-rel+rpl-inv+trk),ct_label >>>>>> ct_state(-new+est-rel-rpl-inv+trk),ct_label >>>>>> >>>>>> I also tried it out on a Fedora 34 with 5.13.14-200.fc34.x86_64, still >>>>>> works fine. >>>>>> >>>>>> What kernel and openvswitch module versions do you use? >>>>>> >>>>> On my box there is CentOS 7.5 with kernel 3.10.0-862.14.4.el7 and OOT >>>>> kernel module. >>>>> I’ve tested two versions, in both the problem was hit: >>>>> openvswitch-kmod-2.13.4-1.el7_5.x86_64 >>>>> openvswitch-kmod-2.16.0-1.el7_5.x86_64 >>>>> >>>>> Do you think the problem could be related to kernel (conntrack) and >>>>> kernel must be upgraded here? >>>>> Or, maybe I should try master OVS, as you did? >>>> >>>> I just tried with OVS v2.13.4, OVN master and it all worked fine (both >>>> on Fedora 34 and rhel 7). I don't think the problem is in user space. >>>> >>>> Regards, >>>> Dumitru >>>> >>>> _______________________________________________ >>>> dev mailing list >>>> d...@openvswitch.org <mailto:d...@openvswitch.org> >>>> <mailto:d...@openvswitch.org <mailto:d...@openvswitch.org>> >>>> <mailto:d...@openvswitch.org <mailto:d...@openvswitch.org> >>>> <mailto:d...@openvswitch.org <mailto:d...@openvswitch.org>>> >>>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev> >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev>> >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev><https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev>>> >>> _______________________________________________ >>> dev mailing list >>> d...@openvswitch.org <mailto:d...@openvswitch.org> >>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev >>> <https://mail.openvswitch.org/mailman/listinfo/ovs-dev> >> > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
