Hi guys,
We followed the debug steps and using perf we got the following
performance trace:
- 84.56% 0.01% ovn-controller [.] main
- 84.56% main
- 78.52% pinctrl_run
- 39.14% lport_lookup_by_name
- 36.66% ovsdb_idl_index_find
- skiplist_find
- 36.36% skiplist_forward_to (inlined)
- skiplist_forward_to_
- 31.99%
ovsdb_idl_index_generic_comparer.part.0
- 24.68% ovsdb_datum_compare_3way
- 13.18% ovsdb_atom_compare_3way
8.38% json_string
6.27% __strcmp_evex
6.28% ovsdb_idl_read
+ 1.07% sbrec_port_binding_index_set_logical_port
0.72% ovsdb_idl_index_destroy_row
0.60% ovsdb_idl_index_init_row
- 15.04% extract_ip_addresses
- parse_and_store_addresses
- 9.90% add_ipv6_netaddr
- 9.36% __GI_inet_ntop (inlined)
+ inet_ntop6 (inlined)
+ 2.78% ipv6_parse_cidr_len
+ 2.14% ip_parse_cidr_len
+ 8.35% smap_get
+ 4.93% smap_get_int
+ 3.00% shash_find_data
+ 2.00% ipv6_parse
+ 1.31% eth_addr_from_string
- 4.46% bfd_run
- 2.00% sset_add
1.43% hash_bytes
0.81% encaps_run
Just to recall, only when the ovn-controller receives the update for
ovn-interconnect logical flows (that's not happen with regular logical
flows) that load spike happens.
We are looking into the lport_lookup_by_name function to try to
understand what is the relation with the ovn-interconnect logical
flows.
Regards,
Tiago Pires
On Tue, Jan 7, 2025 at 5:54 AM Felix Huettner
<felix.huettner@stackit.cloud> wrote:
>
> On Sat, Jan 04, 2025 at 09:59:28PM -0500, Satish Patel wrote:
> > Hi Felix,
> >
> > Are there any documents on OVN troubleshooting the way you explain? LIke
> > what logs to look at, what tools to use to dump perf data and tech support
> > style data to drill down the issue before we report to developers. I
> > heard in the past related ovn-controller CPU usage 100% etc. But there is
> > no better way to find out what causes those spikes and errors.
>
> Hi Satish,
>
> i do not know of any documents regarding that. The questions below are
> based on my experience of looking at similar issues in the past.
>
> I also do not yet have a nice way to get perf information for spikes,
> but most of the time running inc-engine/recompute converts a spike to a
> continuous 100% cpu usage, which i find easier to analyse.
>
> To get the perf information you can do the following:
> * Ensure you have ovn-controller debug symbols available (that depends
> on your installation method how to do that)
> * Install "perf". E.g. for ubuntu it would be something like "apt install
> linux-tools-generic binutils libc-dbg"
> * Run "perf record -p $(pidof ovn-controller) -g --call-graph dwarf"
> while the recomputes are running
> * Press CTRL+C after a few recompute iterations
> * Wait for "perf record" to finish. Do not press CTRL+C again until it
> is done. Depending on how long it ran this can take some time.
> * Run "perf report -g". This will parse the profile and output a nice ui
> * You will see a list of functions and before them the percentage of CPU
> time that the process spend in there (once in the function only and
> once in the function and all subfunctions)
> * Expand the tree using the "+" key and follow mostly the top 2
> percentages after expansion
> * Probably somewhere in there there is something to optimize (or that
> has already been optimized)
>
> You will see something similar as the "performance trace" in this commit
> message
> https://github.com/ovn-org/ovn/commit/ea619bf64ce1ae00996928f7ed15309a690ee3b9
> In that case the bfd_calculate_chassis was the one that was optimized.
>
> I hope that helps.
>
> Felix
>
>
> >
> > On Thu, Jan 2, 2025 at 9:48 AM Felix Huettner via discuss <
> > ovs-discuss@openvswitch.org> wrote:
> >
> > > On Thu, Jan 02, 2025 at 08:47:34AM -0300, Tiago Pires via discuss wrote:
> > > > Hi all,
> > > >
> > > > While creating ovn interconnect logical flows (Transit switch, LRPs
> > > > and LSPs) for a Logical Router in an AZ, there is load spike in all
> > > > chassis's ovn-controllers to 100%.
> > > > This remains for 1 minute and half and returns to normal after the
> > > > logical flows are installed.
> > > > Since this behavior only manifests itself while creating ovn
> > > > interconnect logical flows, enabling the debug logs shows that the
> > > > ovn-controller receives from SB the following change:
> > > >
> > > >
> > > 2024-12-26T17:38:15.023Z|10562646|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: SB_encap, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:15.023Z|10562647|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: mff_ovn_geneve, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:15.023Z|10562648|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: physical_flow_output, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:15.023Z|10562649|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: flow_output, old_state Unchanged, new_state Stale
> > > > 2024-12-26T17:38:15.032Z|10562650|jsonrpc|DBG|ssl:1XX.XX.XX.X16:6642:
> > > > received notification, method="update3",
> > > >
> > > params=[["monid","OVN_Southbound"],"9c54ec46-83a4-4deb-877d-3089a99ae482",{"SB_Global
> > > >
> > > ":{"019c4225-e637-4881-b382-36fdfcb9e0c9":{"modify":{"nb_cfg":34448}}},"Port_Binding":{"4230d38a-75cd-4f1c-9fde-62e753958656":{"insert":{"up":false,"tunnel_key":7,"mac":"16:00:01:f4:03:cb
> > > > 169.254 .30.3/24
> > > >
> > > fe80:30::3/64","datapath":["uuid","e84addb8-efdd-48bc-8454-8dd76a4a5a19"],"logical_port":"bd7bae47-2482-41cc-9486-e66f9d7b25bf-lrp-793b8","type":"patch"}},"f4d71615-88b8-4274-87ab-448cf8
> > > > c6a6ee":{"insert":{"up":false,"tunnel_key":6,"mac":"16:00:01:75:f8:87
> > > > 169.254.10.1/24
> > > >
> > > fe80:10::1/64","datapath":["uuid","e84addb8-efdd-48bc-8454-8dd76a4a5a19"],"logical_port":"bd7bae47-2482-41cc-
> > > >
> > > 9486-e66f9d7b25bf-lrp-ba453","type":"patch"}},"3eac57dd-386c-43b0-bf5b-8225941b52cb":{"insert":{"up":false,"tunnel_key":5,"mac":"16:00:01:9a:30:fa
> > > > 169.254.40.4/24 fe80:40::4/64","datapath":["uuid
> > > >
> > > ","e84addb8-efdd-48bc-8454-8dd76a4a5a19"],"logical_port":"bd7bae47-2482-41cc-9486-e66f9d7b25bf-lrp-36ac0","type":"patch"}},"7295d5c6-ff8d-4f4f-b1a5-eb1ca87fcb7d":{"insert":{"up":false,"tunnel_key
> > > > ":8,"mac":"16:00:01:de:df:b5 169.254.20.2/24
> > > >
> > > fe80:20::2/64","datapath":["uuid","e84addb8-efdd-48bc-8454-8dd76a4a5a19"],"logical_port":"bd7bae47-2482-41cc-9486-e66f9d7b25bf-lrp-c21c6","type":"patc
> > > >
> > > h"}}},"Logical_Flow":{"224852f2-9a46-4569-b51d-5d340ed6f4b4":{"modify":{"logical_dp_group":["uuid","bd825723-9a0e-451c-b5ad-b7d6f9cc75e4"]}},"05f5d515-bccf-47c1-9d55-8a4dfce88822":{"insert":{"pip
> > > > eline":"ingress","match":"inport ==
> > > > \"bd7bae47-2482-41cc-9486-e66f9d7b25bf-lrp-36ac0\" && ip6.dst ==
> > > >
> > > fe80::/64","priority":194,"logical_datapath":["uuid","e84addb8-efdd-48bc-8454-8dd76a4a5a19"],"
> > > > table_id":13,"actions":"ip.ttl--; reg8[0..15] = 0; xxreg0 = ip6.dst;
> > > > xxreg1 = fe80::1400:1ff:fe9a:30fa; eth.src = 16:00:01:9a:30:fa;
> > > > outport = \"bd7bae47-2482-41cc-9486-e66f9d7b25bf-lrp-36ac0\";
> > > > flags.loopback = 1;
> > > >
> > > next;"}},"c67ec1ee-bfc1-47e0-b35c-95fcc2adc13b":{"modify":{"logical_dp_group":
> > > >
> > > > The addresses from the above change (16:00:01:75:f8:87 169.254.10.1/24
> > > > fe80:10::1/64) are configured into the LRP connected to the transit
> > > > switch.
> > > >
> > > > After while another incremental processing is started:
> > > >
> > > > 2024-12-26T17:38:18.035Z|11190795|coverage|INFO|Skipping details of
> > > > duplicate event coverage for hash=db09e857
> > > > 2024-12-26T17:38:18.035Z|11190796|poll_loop|DBG|wakeup due to [POLLIN]
> > > > on fd 3 (1XX.XX.XX.X99:47382<->1XX.XX.XX.X16:6642) at
> > > > lib/stream-ssl.c:842 (100% CPU usage)
> > > > 2024-12-26T17:38:18.035Z|11190797|inc_proc_eng|DBG|Initializing new
> > > > run
> > > 2024-12-26T17:38:18.035Z|11190798|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: SB_sb_global, old_state Updated, new_state Stale
> > > >
> > > 2024-12-26T17:38:18.035Z|11190799|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: northd_options, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:18.035Z|11190800|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: SB_dhcp_options, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:18.035Z|11190801|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: SB_dhcpv6_options, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:18.035Z|11190802|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: dhcp_options, old_state Unchanged, new_state Stale
> > > >
> > > 2024-12-26T17:38:18.035Z|11190803|inc_proc_eng|DBG|lib/inc-proc-eng.c:379:
> > > > node: SB_address_set, old_state Unchanged, new_state Stale
> > > >
> > > > In other chassis we observerd the recompute time increasing to 18secs:
> > > >
> > > > 2024-12-26T17:38:46.463Z|40096697|poll_loop|INFO|Dropped 72 log
> > > > messages in last 6 seconds (most recently, 0 seconds ago) due to
> > > > excessive rate 2024-12-26T17:38:46.463Z|40096698|poll_loop|INFO|wakeup
> > > > due to [POLLIN] on fd 26 (1XX.XX.XX.6:56350<->1XX.XX.XX.X16:6642) at
> > > > lib/stream-ssl.c:842 (99% CPU usage)
> > > > 2024-12-26T17:38:52.442Z|40096699|poll_loop|INFO|Dropped 72 log
> > > > messages in last 6 seconds (most recently, 0 seconds ago) due to
> > > > excessive rate 2024-12-26T17:38:52.442Z|40096700|poll_loop|INFO|wakeup
> > > > due to [POLLIN] on fd 26 (1XX.XX.XX.6:56350<->1XX.XX.XX.X16:6642) at
> > > > lib/stream-ssl.c:842 (102% CPU usage)
> > > > 2024-12-26T17:38:58.409Z|40096701|poll_loop|INFO|Dropped 72 log
> > > > messages in last 6 seconds (most recently, 0 seconds ago) due to
> > > > excessive rate 2024-12-26T17:38:58.409Z|40096702|poll_loop|INFO|wakeup
> > > > due to [POLLIN] on fd 26 (1XX.XX.XX.6:56350<->1XX.XX.XX.X16:6642) at
> > > > lib/stream-ssl.c:842 (101% CPU usage)
> > > > 2024-12-26T17:39:04.477Z|40096703|poll_loop|INFO|Dropped 72 log
> > > > messages in last 6 seconds (most recently, 0 seconds ago) due to
> > > > excessive rate 2024-12-26T17:39:04.477Z|40096704|poll_loop|INFO|wakeup
> > > > due to [POLLIN] on fd 26 (1XX.XX.XX.6:56350<->1XX.XX.XX.X16:6642) at
> > > > lib/stream-ssl.c:842 (98% CPU usage)
> > > > 2024-12-26T17:39:27.896Z|40096705|inc_proc_eng|INFO|node:
> > > > logical_flow_output, recompute (forced) took 18932ms
> > > > 2024-12-26T17:39:28.612Z|40096706|inc_proc_eng|INFO|node:
> > > > physical_flow_output, recompute (forced) took 670ms
> > > > 2024-12-26T17:39:30.614Z|40096707|timeval|WARN|Unreasonably long
> > > > 22134ms poll interval (19780ms user, 2315ms system)
> > > > 2024-12-26T17:39:30.614Z|40096708|timeval|WARN|faults: 2634558 minor,
> > > > 0 major 2024-12-26T17:39:30.614Z|40096709|timeval|WARN|disk: 0 reads,
> > > > 8 writes 2024-12-26T17:39:30.614Z|40096710|timeval|WARN|context
> > > > switches: 0 voluntary, 2688 involuntary
> > > >
> > > > This behavior only happens with ovn interconnect logical flows, do you
> > > > know any known issue regarding it?
> > >
> > > Hi Tiago,
> > >
> > > from the log above it seems like some part of the previous incremental
> > > processing run failed and caused a recompute afterwards. So the last
> > > logs are no longer incrementally processed.
> > >
> > > There should be some log line in between similar to "...forcing recompute
> > > next time...". That might help you find the cause of the recompute.
> > >
> > > Additionally you should be able to trigger a recompute manually with
> > > "ovn-appctl inc-engine/recompute". Then you will probably observe
> > > similar logs.
> > > You could then attach a perf to the ovn-controller for one or more
> > > recomputes and use "perf record" and "perf report" with call graphs to
> > > figure out what exactly takes long. That might be helpful information
> > > for further optimizations.
> > >
> > > Also ovn got significant improvements in incremental processing since
> > > 23.03, so an upgrade might help as well.
> > >
> > > Hope that helps
> > > Felix
> > >
> > >
> > > >
> > > > #Versions in use
> > > >
> > > > $ ovn-nbctl -V
> > > > ovn-nbctl 23.03.1
> > > > Open vSwitch Library 3.1.3
> > > > DB Schema 7.0.0
> > > >
> > > > $ ovs-vsctl -V
> > > > ovs-vsctl (Open vSwitch) 3.1.3
> > > > DB Schema 8.3.1
> > > >
> > > > external_ids: ovn-monitor-all="true",
> > > > ovn-ofctrl-wait-before-clear="10000", ovn-openflow-probe-interval="0",
> > > > ovn-remote-probe-interval="180000"
> > > >
> > > > Regards,
> > > >
> > > > Tiago Pires
> > > >
> > > > --
> > > >
> > > >
> > > >
> > > >
> > > > _‘Esta mensagem é direcionada apenas para os endereços constantes no
> > > > cabeçalho inicial. Se você não está listado nos endereços constantes no
> > > > cabeçalho, pedimos-lhe que desconsidere completamente o conteúdo dessa
> > > > mensagem e cuja cópia, encaminhamento e/ou execução das ações citadas
> > > estão
> > > > imediatamente anuladas e proibidas’._
> > > >
> > > >
> > > > * **‘Apesar do Magazine Luiza tomar
> > > > todas as precauções razoáveis para assegurar que nenhum vírus esteja
> > > > presente nesse e-mail, a empresa não poderá aceitar a responsabilidade
> > > por
> > > > quaisquer perdas ou danos causados por esse e-mail ou por seus anexos’.*
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > discuss mailing list
> > > > disc...@openvswitch.org
> > > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> > > _______________________________________________
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> > > disc...@openvswitch.org
> > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> > >
--
_‘Esta mensagem é direcionada apenas para os endereços constantes no
cabeçalho inicial. Se você não está listado nos endereços constantes no
cabeçalho, pedimos-lhe que desconsidere completamente o conteúdo dessa
mensagem e cuja cópia, encaminhamento e/ou execução das ações citadas estão
imediatamente anuladas e proibidas’._
* **‘Apesar do Magazine Luiza tomar
todas as precauções razoáveis para assegurar que nenhum vírus esteja
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