network_stuff:juniper:telemetry

MDT (Model Driven Telemetry): Replaces SNMP

What is gRPC (streaming telemetry)

Google Remote Procedure call (remote call on the device) . Is an open source alternative/improvement to classic restAPI. It adds consistency, also uses binary messages instead of json text so it's more efficient traffic-wise. Uses standard language: protobuf which is supported by python among others.
- protobuf 'file' define what RPCs are available. Is provided by the vendor and abstracts the way to interact to the system.
  - We convert or compile 'protobuf' to python libraries. 'Protoc' creates a library that you can start using straight away in your code

The messages are binary but we can do marshaling and see the key-value pairs with 'kgbb'
It uses http2 by default (port 50051). With a single channel it can send a bunch of requests. So only one http handshake is needed.
- All is defined in the client (jti-client in our case) (define how many channels, etc)

gNMI
See this insight on prometheus-grafana-exporters and gnmi: monitoring_cisco_networks_with_prometheus_grafana_and_exporters_fintech_focus_.pdf

Provides 1) Network Management and 2) Streaming telemetry
Uses HTTP/TCP so reliable compared to snmp
And also extremely light. It uses RPCs more efficiently than netconf (like it were issued in the target machine itself) See comparison
gRPC Network Management Interface. Is a way to interact to grpc with Standard, reduced, RPCs.
gnmi defines Four RPCs:
- capabilities (“show me what you can offer”)
- get (like a netconf get)
- set (like a netconf set, also to update and delete)
- subscribe ( hook to a stream )
Junos in particular uses the JTI client which includes gNMI : Junos Telemetry Interface Client (jtimon) is an application that can be used to collect telemetry streams from a Juniper device streaming in native format over UDP, or in OpenConfig format over gRPC.

Topology ( gNMI + Telegraf plugin)

MESSAGE QUEUING TECHNOLOGIES

The client subscribes to the server/broker but the client can receive or send data
Topics are labels that you publish messages to and subscribe to. They are arranged as a hierarchy

Kafka
Kafka focuses on the storage and reading of data, aiming at streaming data processing scenarios with high real-time performance

MQTT - MQ Telemetry Transport
is a lightweight, publish-subscribe, machine to machine network protocol for Message queue/Message queuing service. It is designed for connections with remote locations that have devices with resource constraints.

sudo apt install mosquitto mosquitto-clients    # creates the broker. This can be a simple raspberry pi
mosquitto_sub -h localhost -t test    # Test subscription to a test topic (still non-existing)
mosquitto_pub -h localhost -t test -m "hello world"    # publishes a test message in the 'test' topic
!
mosquitto_sub -h <host> -t /merakimv/<serial of device>/<topic>    # subscribes

Then PMACCT (pmaccount) to correlate information and extract trends: pmacct is a small set of multi-purpose passive network monitoring tools [NetFlow IPFIX sFlow libpcap BGP BMP RPKI IGP Streaming Telemetry].

References: