605 09 06-16-mdtforckn · • product management trends ... sensor-path cisco-ios-xr-infra-statsd-...

Shelly Cadora Principal Engineer, Technical Marketing

Model-Driven Telemetry

2 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

Use Cases •  Network Health •  Troubleshooting / Remediation •  SLAs, Performance Tuning •  Capacity Planning •  Product Management

Trends •  Centralized / Software-defined •  Speed •  Scale

We Need More Data

Capabilities


SNMP

Incomplete

Scale Issues

Unstructured Subject to

Change

storage & analysis

sensing & measurement

Network data is bottlenecked

Where Data Is Created Where Data Is Useful

CLI

Syslog

SNMP Server

Syslog Collector

Scripts

Non real time

Strong burden on back-end

Must normalize different encodings, transports, data

models, timestamps


The New Paradigm – Free the Data

sensing & measurement

Where Data Is Created Where Data Is Useful

T

T

T

Real time

As Much Data As Fast As Useful As Easy As Possible

Storage & analysis


Three Enablers for Telemetry

Push Not Pull

Analytics-Ready Data

Data-Model Driven


Instruction on: •  What data to collect •  With what cadence •  And send to where

Ultra-high level picture: Config

Collector


telemetry model-driven destination-group DGroup1 address family ipv4 10.60.19.8 port 2104 encoding self-describing-gpb protocol tcp! sensor-group SGroup1 sensor-path Cisco-IOS-XR-infra-statsd-

oper:infra-statistics/interfaces/interface/latest/generic-counters

! subscription Sub1 sensor-group-id SGroup1 sample-interval 30000 destination-id DGroup1

Sample CLI (XR 6.1.1)

What Data to Collect

Where to Send and How

When


Config Model (XR 6.1.1) What Data to Collect


When

What Data to Collect


When

https://xrdocs.github.io/telemetry/tutorials/


module: Cisco-IOS-XR-infra-statsd-oper +--ro infra-statistics +--ro interfaces +--ro interface* [interface-name] +--ro latest +--ro generic-counters +--ro packets-received +--ro bytes-received +--ro packets-sent +--ro bytes-sent +--ro multicast-packets-received +--ro broadcast-packets-received +--ro multicast-packets-sent etc…

How to Get Supported Models •  https://github.com/YangModels/yang/

tree/master/vendor/cisco/xr

•  NETCONF <capabilities>

Some Commonly Used Models

Use YANG Models in Sensor-Path


Ultra-high level picture: Transport Instruction on: •  What data to collect •  With what cadence •  And send to where

Collector Table 3 Table 2 Table 1


Dial-Out

•  TCP & gRPC

Dial-In

•  gRPC only

Three Transport Options

Collector

Data

SYN SYN-ACK

ACK Collector

Data

SYN SYN-ACK

ACK


gRPC: Like REST But Different

Runs over HTTP/2 • Optimize for page load time • Server push, header compression, multiplexing,

TLS • RFC 7540 (May 2015) • Preserves most HTTP1.1 syntax

Defines Services (“RPCs”)

Encodes Using Google Protocol Buffers (“GPB” or “protobufs”)

•  Services and Messages •  Auto-generate code in many languages

12

http://www.grpc.io/docs/#hello-grpc


Instruction on: •  What data to collect •  With what cadence •  And send to where

Receiving unit Table 3 Table 2

Interface ifInErrors ifOutErrors ifHCOutOctets …

HundredGigabitEthernet 0/1/0/2 10 0 123456789 …

Bundle-Ether 42

3 0 234567890 …

… … … … …

Table 1

Ultra-high level picture: Encoded Data “I am the interface counters table”


Basic Concept: Encoding

Encoding (or “serialization”) translates data (objects, state) into a format that can be transmitted across the network. When the receiver decodes (“de-serializes”) the data, it has an semantically identical copy of the original data.

DATA

DATA

“Decode”

“Encode”

Common Text-Based Encodings

•  JSON •  XML


GPB Encoding

Design Goals

•  Simplicity •  Performance •  Forward/Backward

Compatibility

Non-Goals

•  Human-Readable •  Self-Describing •  Text-based

Google Protocol Buffers (GPB)

Call them “protobufs”

for short “Protocol buffers are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data – think XML, but smaller, faster, and simpler.”


Telemetry Has Two GPB Encoding Options

1: GigabitEthernet0/0/0/0 50: 449825 51: 41624083 52: 360333 53: 29699362 54: 91299 <snip>

2X faster Operationally more complex (but not relative to SNMP!)

{InterfaceName: GigabitEthernet0/0/0/0 GenericCounters { PacketsSent: 449825 BytesSent: 41624083 PacketsReceived: 360333 BytesReceived: 29699362 MulticastPacketsReceived: 91299 <snip>

3X larger Native models: still need heuristics for key names

GPB – “compact” GPB – “self-describing”


Lesson Learned: It’s Not Hard to Beat SNMP

•  10 second poll / push •  3 pollers / telemetry receivers •  30 minute measurement intervals

•  288 100Gig E Interfaces (Line Rate) •  SNMP: IF-MIB (query by row)


Use Case: Bundle Polarization

Telemetry – 10 Second Push SNMP – 1 Minute Polling

G0/0/0/0 G0/0/0/1

Is the bundle polarized?


Use Case: Bundle Polarization

Telemetry – 10 Second Push G0/0/0/0 G0/0/0/1

Is the bundle polarized?


Use Case: Packet Loss Interpolation

VPN, Internet,

etc…

No Drops No Drops Drops Yours Yours

Not Yours

Pkts Tx

Pkts Rx

•  SNMP polling (5 min) •  first order linear interpolation •  detects ~10% packet loss

•  Telemetry (10-30 sec) •  Polynomial interpolation •  Smaller losses, faster


Different Customers, Different Models

Logstash

ElasticSearch

Kibana

ST Input Codec

Output Codec

Kafka

BYO Black Box

SST

Custom Open Source, Customizable

Proprietary or OS-based

SST

Commercial Stack

Prometheus Panda


6.0.0 / 6.0.1

• 30 -> 10 Seconds

• Periodic • RP level • JSON, GPB • TCP, UDP • Native schemas • File-based policy • Open Source

tooling

6.1.1 “MDT”

• YANG-modeled data

• OpenConfig YANG

• Config/model-based policy

• gRPC

Future

• Event-based • Low-level data

Telemetry is a Journey


Tutorials and Blogs •  https://xrdocs.github.io/telemetry/ •  https://developer.cisco.com/site/ios-xr/ (devnet landing page for telemetry) •  http://blogs.cisco.com/sp/the-limits-of-snmp •  http://blogs.cisco.com/sp/why-you-should-care-about-model-driven-

telemetry •  https://youtu.be/tIN8BjHwpNs (NANOG 67: 10 Lessons from Telemetry)

YANG •  https://github.com/YangModels/yang/tree/master/vendor/cisco (Cisco

YANG models) •  https://github.com/CiscoDevNet/openconfig-getting-started (lots of

sample code)


Telemetry Tools on Github: •  https://github.com/cisco/bigmuddy-network-telemetry-stacks •  https://github.com/cisco/bigmuddy-network-telemetry-

collector

Demos and Lab •  https://dcloud-cms.cisco.com/ (dCloud telemetry lab) •  https://www.sdxcentral.com/resources/sdn-demofriday/cisco-

ios-xr-signalfx-demo-monitoring-your-modern-network/ (demo with signalFX)

•  https://youtu.be/F_S9-ctNFe0 (demo on NCS 5508)


Demo

605 09 06-16-mdtforckn · • product management trends ... sensor-path cisco-ios-xr-infra-statsd-...

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