Fix for SFLOW-1 to work with non-default sampling rate

[singh-prem]

This PR adds a deviation to allow a different ingress sampling rate than 1/1,000,000 for platforms.
No change is needed for a platform that supports default ingress sampling rate.

[OpenConfigBot]

Pull Request Functional Test Report for #3978 / ec04da6

Virtual Devices

Device	Test	Test Documentation	Job	Raw Log
Arista cEOS		SFLOW-1: sFlow Configuration and Sampling
Cisco 8000E		SFLOW-1: sFlow Configuration and Sampling
Cisco XRd		SFLOW-1: sFlow Configuration and Sampling
Juniper ncPTX		SFLOW-1: sFlow Configuration and Sampling
Nokia SR Linux		SFLOW-1: sFlow Configuration and Sampling
Openconfig Lemming		SFLOW-1: sFlow Configuration and Sampling

Hardware Devices

Device	Test	Test Documentation	Raw Log
Arista 7808		SFLOW-1: sFlow Configuration and Sampling
Cisco 8808		SFLOW-1: sFlow Configuration and Sampling
Juniper PTX10008		SFLOW-1: sFlow Configuration and Sampling
Nokia 7250 IXR-10e		SFLOW-1: sFlow Configuration and Sampling

Help

[masood-shah]

this implements the use of the deviation but doesnt explain why the default might be unsupported or where the value 262144 comes from. could you please link the specific technical reference (eg, Cisco doc ID, bug) that documents this platform's min supported ingress sFlow sampling rate and the technical justification for its deviation from the default within this test suite?

[dplore]

this implements the use of the deviation but doesnt explain why the default might be unsupported or where the value 262144 comes from. could you please link the specific technical reference (eg, Cisco doc ID, bug) that documents this platform's min supported ingress sFlow sampling rate and the technical justification for its deviation from the default within this test suite?

We need to decide if the deviated sample rate is acceptable for this test? The 1/1,000,000 rate was our operational standard. If we want to allow different rates or a range of rates, this test is the place to specify it. Can you help figure out our requirement @masood-shah ?

[masood-shah]

this implements the use of the deviation but doesnt explain why the default might be unsupported or where the value 262144 comes from. could you please link the specific technical reference (eg, Cisco doc ID, bug) that documents this platform's min supported ingress sFlow sampling rate and the technical justification for its deviation from the default within this test suite?

We need to decide if the deviated sample rate is acceptable for this test? The 1/1,000,000 rate was our operational standard. If we want to allow different rates or a range of rates, this test is the place to specify it. Can you help figure out our requirement @masood-shah ?

this implements the use of the deviation but doesnt explain why the default might be unsupported or where the value 262144 comes from. could you please link the specific technical reference (eg, Cisco doc ID, bug) that documents this platform's min supported ingress sFlow sampling rate and the technical justification for its deviation from the default within this test suite?

We need to decide if the deviated sample rate is acceptable for this test? The 1/1,000,000 rate was our operational standard. If we want to allow different rates or a range of rates, this test is the place to specify it. Can you help figure out our requirement @masood-shah ?

Happy to help, but first, could someone explain how the values 1/1,000,000 and 262,144 were derived or determined?

[arvbaska1]

this implements the use of the deviation but doesnt explain why the default might be unsupported or where the value 262144 comes from. could you please link the specific technical reference (eg, Cisco doc ID, bug) that documents this platform's min supported ingress sFlow sampling rate and the technical justification for its deviation from the default within this test suite?

the min. and max. supported sample rate can differ based on platforms, for 8000 it can sample from 1:1 to 1:262144
sample rate. This documented below.
https://www.cisco.com/c/en/us/td/docs/iosxr/cisco8000/netflow/configuration/b-netflow-configuration-ios-xr-8000/netflow-sflow-key-concepts.html#flow-sampler

[dplore]

This needs to be wrapped with a conditional (if the deviation exists, then use it).
for example:

		if deviations.SflowIngressMinSamplingRate(d) {
			switch d.Vendor() {
			case ondatra.CISCO:
             		        c.SetIngressSamplingRate(deviations.SflowIngressMinSamplingRate(d))
			}
		} else {
		        c.IngressSamplingRate = ygot.Uint32(1000000)
		}

It is still up to @masood-shah to decide to approve

[dplore]

Masood approved, so we just need to see the if statement implemented and then we can merge it

[arvbaska1]

sure, ack.

[arvbaska1]

@dplore Could you help review the PR (run the checks) , the requested changes have been made

[coveralls]

Pull Request Test Coverage Report for Build 16622485930

Details

• 0 of 84 (0.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 13.559%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/deviations/deviations.go	0	3	0.0%
internal/cfgplugins/sflow.go	0	8	0.0%
proto/metadata_go_proto/metadata.pb.go	0	73	0.0%

Totals
Change from base Build 16612959286:	-0.05%
Covered Lines:	2093
Relevant Lines:	15436

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💛 - Coveralls