Skip to content

media_settings.json tuning values are lost in APPL_DB after swss container is restarted #21902

@arista-nwolfe

Description

@arista-nwolfe

The media_settings.json tuning file is used on certain SKUs to apply L1 tuning to ports.
E.G. https://github.com/sonic-net/sonic-buildimage/blob/master/device/arista/x86_64-arista_7800r3a_36d2_lc/media_settings.json

However that tuning seems to go away if the swss container is restarted.

Steps to reproduce:

  1. I see the media_settings tuning in APPL_DB:
    root@cmp206-4:~# sonic-db-cli -n asic0 APPL_DB hgetall "PORT_TABLE:Ethernet96"
    {'admin_status': 'up', 'alias': 'Ethernet13/1', 'asic_port_name': 'Eth96', 'core_id': '0', 'core_port_id': '13', 'description': 'ARISTA13T3:Ethernet1', 'fec': 'rs', 'index': '13', 'lanes': '40,41,42,43', 'mtu': '9100', 'num_voq': '8', 'pfc_asym': 'off', 'role': 'Ext', 'speed': '100000', 'tpid': '0x8100', 'oper_status': 'up', 'flap_count': '1', 'main': '0x4e,0x4e,0x53,0x4b', 'post1': '0xffffffea,0xffffffea,0xffffffea,0xffffffec', 'post2': '0x0,0x0,0x0,0x0', 'post3': '0x0,0x0,0x0,0x0', 'pre1':'0xfffffffb,0xfffffffb,0xfffffffb,0xfffffffb', 'pre2': '0x0,0x0,0x0,0x0', 'last_up_time': 'Fri Feb 28 23:16:47 2025'}

  2. Then I restarted the swss service or the swss0 docker:
    systemctl restart swss@0.service
    docker restart swss0

  3. Now I no longer see the media_settings tuning on the ports:
    root@cmp206-4:~# sonic-db-cli -n asic0 APPL_DB hgetall "PORT_TABLE:Ethernet96"
    {'admin_status': 'up', 'alias': 'Ethernet13/1', 'asic_port_name': 'Eth96', 'core_id': '0', 'core_port_id': '13', 'description': 'ARISTA13T3:Ethernet1', 'fec': 'rs', 'index': '13', 'lanes': '40,41,42,43', 'mtu': '9100', 'num_voq': '8', 'pfc_asym': 'off', 'role': 'Ext', 'speed': '100000', 'tpid': '0x8100', 'oper_status': 'up', 'flap_count': '1', 'last_up_time': 'Fri Feb 28 23:56:34 2025'}

Note 1: Bringing the port down and up doesn't bring back the tuning values, however, restarting the pmon service will bring back the tuning values systemctl restart pmon.service

Note 2: If auto_restart=enabled for swss then an OA crash will be enough to reproduce this issue

Metadata

Metadata

Assignees

Labels

Triagedthis issue has been triaged

Type

No type

Projects

Status

No status

Milestone

No milestone

Relationships

None yet

Development

No branches or pull requests

Issue actions