[SWSS] Static LAG Support #3090

kannansel · 2024-03-25T18:38:39Z

What I did
Static lag support changes in SWSS module
sonic-net/SONiC#1039

Why I did it
PXE application doesnt support LAG during boot. and also some legacy device doesnt support lacp.
To achieve more bandwidth with those legacy devices static lag will be useful

How I verified it

UT:-
        Test cases
1       Create static port channel with static flag     pass    pass
2       verify static has option flag true or false     pass    pass
3       Add static member see the portchannel is up     pass    pass
4       verify teamd is created with round-robin option by default
pass    pass
5       Remove last portchannel member check port channel down  pass
pass
6       Remove portchannel member check port channel still up   pass
pass
7       verify teamdctl config dump     pass    pass
8       verify teamdctl state dump      pass    pass
9       shutdown the portchannel check the kernel state pass    pass
10      no shutdown the portchannel check the kernel state      pass
pass
11      "Check the show output matches the review comment
root@sonic:~# show inter port
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not
available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev       Protocol     Ports
-----  -------------  -----------
-----------------------------------------
   01  PortChannel01  LACP(A)(Up)  Ethernet16(S)
   02  PortChannel02  NONE(A)(Up)  Ethernet48(S) Ethernet64(S)
Ethernet32(S)
root@sonic:~#
12      teamnl is set to roundrobin     pass    pass
13      save and reload and verify portchannel is up    pass    pass
14      "docker restart teamd
teamd stopped
swss stopped
syncd stopped

swss started
syncd started
teamd started"  pass    pass
15      warm-reboot fails even without any port channel config  fail
16      verify teamd settles doesnt hog cpu with 100% cpu usage pass
17      "trying with static port channel config on non supported
branches
port channel will be configured as LACP."               pass

Not Supported Options
1. Min links and
2. fall back are not supported

Details if related

Patch explanation
1. static lag supported with option roundrobin.
2. tlm_teamd -> teamdctl changes to handle json dump for static lag.
3. test cases -> updated

Why ? Static lag support changes in SWSS module sonic-net/SONiC#1039 Patch explanation 1. static lag supported with option roundrobin. 2. tlm_teamd -> teamdctl changes to handle json dump for static lag. 3. test cases -> updated UT:- Test cases 1 Create static port channel with static flag pass pass 2 verify static has option flag true or false pass pass 3 Add static member see the portchannel is up pass pass 4 verify teamd is created with round-robin option by default pass pass 5 Remove last portchannel member check port channel down pass pass 6 Remove portchannel member check port channel still up pass pass 7 verify teamdctl config dump pass pass 8 verify teamdctl state dump pass pass 9 shutdown the portchannel check the kernel state pass pass 10 no shutdown the portchannel check the kernel state pass pass 11 "Check the show output matches the review comment root@sonic:~# show inter port Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available, S - selected, D - deselected, * - not synced No. Team Dev Protocol Ports ----- ------------- ----------- ----------------------------------------- 01 PortChannel01 LACP(A)(Up) Ethernet16(S) 02 PortChannel02 NONE(A)(Up) Ethernet48(S) Ethernet64(S) Ethernet32(S) root@sonic:~# 12 teamnl is set to roundrobin pass pass 13 save and reload and verify portchannel is up pass pass 14 "docker restart teamd teamd stopped swss stopped syncd stopped swss started syncd started teamd started" pass pass 15 warm-reboot fails even without any port channel config fail 16 verify teamd settles doesnt hog cpu with 100% cpu usage pass 17 "trying with static port channel config on non supported branches port channel will be configured as LACP." pass Not Supported Options 1. Min links and 2. fall back are not supported

UT fixes

saiarcot895 · 2024-03-30T01:03:45Z

I think the fallback LAG feature described here does the same thing basically, except that it allows LACP to be established once the peer device is in a state to start sending LACP packets?

There is one bug related to the LAG containing multiple ports that's fixed in sonic-net/sonic-buildimage#10823.

kannansel · 2024-04-01T06:31:59Z

I think the fallback LAG feature described here does the same thing basically, except that it allows LACP to be established once the peer device is in a state to start sending LACP packets?

There is one bug related to the LAG containing multiple ports that's fixed in sonic-net/sonic-buildimage#10823.

Hi Sai,

Static LAG doesnt involve any protocol or timer (will be more suitable where we will not rely on any lacp control packets).
Will be useful in customer scenarios (as stop gap solution along with PxE) if we face any customer related issues with LACP control packet receive and forward handling.
LACP fallback feature does involve lacp protocol timer (and also can oscillate between up/down if there is any LACP tx/rx issue in the network).
In master quickly tried only single port comes up right currently... above change is not yet pushed.

Static LAG will be useful and will be immune to any LACP protocol operation (except Link up/down events).

Thanks,
Kannan.S

dgsudharsan · 2024-04-10T00:56:41Z

cfgmgr/teammgr.cpp

+	conf << "'{\"device\":\"" << alias << "\","
+             << "\"hwaddr\":\"" << mac_boot.to_string() << "\","
+             << "\"runner\":{"
+             << "\"name\":\"roundrobin\"";


I believe based on HLD discussion the default mode should be loadbalance and not round robin. Can you please clarify why do we have roundrobin defined as default?
sonic-net/SONiC#1039 (comment)

In addition if we have roundrobin how is it achieved in the hardware. If I understand roundrobin is to send one packet per link in roundrobin fashion https://man.archlinux.org/man/teamd.conf.5.en . However we don't have such hash algorithm in SAI.
If SAI is going with loadbalance we should have the same defined in teamd as well

Hi @dgsudharsan ,

Apologies for the delay... unwell last week (this week too ... )

No Round Robin is only for Linux traffic (CPU traffic), Right now it is not mapped to saiars.h (which support packet spraying in hardware for ECMP and LAG)
Regarding spec will modify to round robin..

With loadbalance facing issue of 100% teamd always thats the reason for the change to roundrobin.

Thanks,
Kannan.S

dgsudharsan · 2024-04-10T01:07:37Z

tlm_teamd/values_store.cpp

+/// @param storage a reference to the temporary storage
+///
+
+void ValuesStore::extract_values_static(const std::string & lag_name, json_t * root, HashOfRecords & storage)


Why do we need to have a separate function to extract values for static? This appears to be duplicate of the existing API. Can you clarify the difference?

teamdctl state information for Static lag and Dynamic LACP are little different.

Dynamic LACP has the following fields along with setup
{
"ports": {
"Ethernet48": {
"ifinfo": {
"dev_addr": "00:e0:ec:cc:a8:de",
"dev_addr_len": 6,
"ifindex": 40,
"ifname": "Ethernet48"
},
"link": {
"duplex": "half",
"speed": 0,
"up": false
},
"link_watches": {
"list": {
"link_watch_0": {
"delay_down": 0,
"delay_up": 0,
"down_count": 5,
"name": "ethtool",
"up": false
}
},
"up": false
},
"runner": {
"actor_lacpdu_info": {
"key": 103,
"port": 49,
"port_priority": 255,
"state": 5,
"system": "00:e0:ec:cc:a8:de",
"system_priority": 65535
},
"aggregator": {
"id": 0,
"selected": false
},
"key": 103,
"partner_lacpdu_info": {
"key": 0,
"port": 0,
"port_priority": 0,
"state": 0,
"system": "00:00:00:00:00:00",
"system_priority": 0
},
"partner_retry_count": 3,
"prio": 255,
"selected": false,
"state": "disabled"
}
}
},
"runner": {
"active": true,
"enable_retry_count_feature": true,
"fallback": true,
"fast_rate": false,
"retry_count": 3,
"select_policy": "lacp_prio",
"sys_prio": 65535
},
"setup": {
"daemonized": true,
"dbus_enabled": false,
"debug_level": 1,
"kernel_team_mode_name": "loadbalance",
"pid": 297,
"pid_file": "/var/run/teamd/PortChannel03.pid",
"runner_name": "lacp",
"zmq_enabled": false
},
"team_device": {
"ifinfo": {
"dev_addr": "00:e0:ec:cc:a8:de",
"dev_addr_len": 6,
"ifindex": 50,
"ifname": "PortChannel03"
}
}
}

Static Lag will not contain the runner option (Dynamic LACP needs runner option to determine peer lacp link protocol information)

{
"ports": {
"Ethernet32": {
"ifinfo": {
"dev_addr": "00:e0:ec:cc:a8:de",
"dev_addr_len": 6,
"ifindex": 39,
"ifname": "Ethernet32"
},
"link": {
"duplex": "half",
"speed": 0,
"up": true
},
"link_watches": {
"list": {
"link_watch_0": {
"delay_down": 0,
"delay_up": 0,
"down_count": 3,
"name": "ethtool",
"up": true
}
},
"up": true
}
},
"Ethernet64": {
"ifinfo": {
"dev_addr": "00:e0:ec:cc:a8:de",
"dev_addr_len": 6,
"ifindex": 37,
"ifname": "Ethernet64"
},
"link": {
"duplex": "half",
"speed": 0,
"up": false
},
"link_watches": {
"list": {
"link_watch_0": {
"delay_down": 0,
"delay_up": 0,
"down_count": 3,
"name": "ethtool",
"up": false
}
},
"up": false
}
}
},
"setup": {
"daemonized": true,
"dbus_enabled": false,
"debug_level": 1,
"kernel_team_mode_name": "roundrobin",
"pid": 49,
"pid_file": "/var/run/teamd/PortChannel02.pid",
"runner_name": "roundrobin",
"zmq_enabled": false
},
"team_device": {
"ifinfo": {
"dev_addr": "00:e0:ec:cc:a8:de",
"dev_addr_len": 6,
"ifindex": 9,
"ifname": "PortChannel02"
}
}
}

Since Static doesnt have those runner information modifying existing LAG Member table done for LACP can create more collaterals, thats the reason for separating it out between Static and LACP.

kannansel requested review from judyjoseph and prsunny as code owners March 25, 2024 18:38

kannansel and others added 2 commits March 26, 2024 08:21

Signed-off-by: kannansel <kannan.selvaraj.duraisami@gmail.com>

7e3fcff

UT fixes

Merge branch 'sonic-net:master' into sonic-swss-lag

7222389

prsunny requested review from saiarcot895 and dgsudharsan March 29, 2024 23:56

dgsudharsan requested changes Apr 10, 2024

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[SWSS] Static LAG Support #3090

[SWSS] Static LAG Support #3090

kannansel commented Mar 25, 2024

saiarcot895 commented Mar 30, 2024

kannansel commented Apr 1, 2024

dgsudharsan Apr 10, 2024

dgsudharsan Apr 10, 2024

kannansel Apr 16, 2024

dgsudharsan Apr 10, 2024

kannansel Apr 16, 2024

[SWSS] Static LAG Support #3090

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[SWSS] Static LAG Support #3090

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