T2 Chassis - SNMP Queue counters value is not as expected after buffer queue deletion

[sanjair-git]

Description

As part of the test 'test_snmp_queue_counters', it is expected that after enabling counters optimization by setting create_only_config_db_buffers entry to 'true' under DEVICE_METADATA, and when device config reload is done (with modified config) after certain buffer queue deletion, the value of the SNMP queue counters should be as expected. (lesser than the counter value before deletion).

But actually, the SNMP queue counters are same as before deletion and config reload.

Steps to reproduce the issue:

1. Run 'test_snmp_queue_counters.py' test on a T2 chassis. (Use #(Multi-asic support for snmp_queue_counters test sonic-mgmt#13637 PR for multi-asic support for the test case)

For manual test,

1. Add 'create_only_config_db_buffers ' field as true, under DEVICE_METADATA section of config_db.json of the dut.
2. Save the file and load the new config.
3. Collect the snmp stats by running 'docker exec snmp snmpwalk -v2c -c public <dut_ip> 1.3.6.1.4.1.9.9.580.1.5.5.1.4.1'
4. Delete the buffer queue for port Ethernet0|3-4 for asic0 under config_db.json
5. Save the config and load the config again.
6. Collect the snmp stats by running 'docker exec snmp snmpwalk -v2c -c public <dut_ip> 1.3.6.1.4.1.9.9.580.1.5.5.1.4.1'

Describe the results you received:

>       pytest_assert((queue_counters_cnt_pre - queue_counters_cnt_post)
                      in [unicast_expected_diff, multicast_expected_diff],
                      "Queue counters actual count {} differs from expected values {}, {}".
                      format(queue_counters_cnt_post, (queue_counters_cnt_pre - unicast_expected_diff),
                             (queue_counters_cnt_pre - multicast_expected_diff)))
E       Failed: Queue counters actual count 64 differs from expected values 56, 48

Ethernet0_queue_cntrs_oid = '1.3.6.1.4.1.9.9.580.1.5.5.1.4.1'

Describe the results you expected:

• The expected value after buffer queue deletion is either 48 or 56, but the total snmp queue counters value is 64 irrespective of the buffer queue deletion and also config reload with modified config.

Output of show version:

SONiC Software Version: SONiC.HEAD.764760-nokia-master-ce6cd4227
SONiC OS Version: 12
Distribution: Debian 12.6
Kernel: 6.1.0-11-2-amd64
Build commit: ce6cd4227
Build date: Tue Jul  9 19:42:23 UTC 2024
Built by: gitlab-runner@sonic-build-server03

Platform: x86_64-nokia_ixr7250e_36x400g-r0
HwSKU: Nokia-IXR7250E-36x400G
ASIC: broadcom
ASIC Count: 2
Serial Number: EAG2-02-052
Model Number: N/A
Hardware Revision: 56
Uptime: 19:30:11 up  9:36,  2 users,  load average: 1.77, 1.79, 1.65
Date: Thu 11 Jul 2024 19:30:11

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[vmittal-msft]

@SuvarnaMeenakshi Can you please help check this ?