Description

SNMP request timeout when CPU utilization is high
Test module[snmp/test_snmp_cpu.py] in sonic-mgmt repo stably reproduce this issue.
Currently the issue is only seen on Cisco 8800 chassis.
Suspectation is on the RP card, including backend ports, there're too much interfaces.

Steps to reproduce the issue:

1. Use 'yes' command to simulate 100% utilization on all CPU processors.
2. Send snmp requests, the timeout generate been seen on interface snmp request.
3. SNMP request time out and fail.

Describe the results you received:

After simulated 100% CPU utilization.
args.json contains mgmt-ip of the RP card.
jianquanye@sonic-mgmt-jianquanye:/var/src/sonic-mgmt-int/tests$ python ../ansible/library/snmp_facts.py args.json
Traceback (most recent call last):
File "../ansible/library/snmp_facts.py", line 1075, in
main()
File "../ansible/library/snmp_facts.py", line 496, in main
for oid, val in varBinds:
ValueError: too many values to unpack (expected 2)
jianquanye@sonic-mgmt-jianquanye:/var/src/sonic-mgmt-int/tests$

Describe the results you expected:

SNMP can successfully pass even with 100% CPU utilization

Output of show version:

(paste your output here)

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):