Welcome to the second webinar in the "Taming the Dragon" series about Zenoh and its use for robotics, autonomous vehicle and Internet-scale HPC communities. What is Zenoh? Zenoh is a Pub/Sub/Query protocol that unifies data in motion, data at rest and computations from embedded microcontrollers up to data centers. In this webinar, Luca Cominardi, our Product Conductor here at ZettaScale Technology, talks about how you can get started with Zenoh. You can read more about Zenoh and give it a try here: https://www.zettascale.tech/product/zenoh Stay up to date with the latest news: Twitter: https://twitter.com/zettascaletech LinkedIn: https://www.linkedin.com/company/zettascaletech/ Website: https://www.zettascale.tech/ Newsletter: http://eepurl.com/igPw31

1. Taming the Dragon — Ep. 2
Getting started
Luca Cominardi, PhD
Product conductor
luca@zettascale.tech

2. Six Episodes
Nov 22nd — Zenoh Genesis
Nov 29th — Zenoh: Getting Started
Dec 6th — ROS/ROS2 Robot-to-Anything with Zenoh
Dec 13th — Zenoh on Microcontrollers and Low Power Networks
Dec 20th — Integrating DataBases and Messaging Protocols with Zenoh
Jan 6th — Data Flow Programming with Zenoh-Flow
All episodes run live on the given day at 10.00 CET and 18.00 CET to facilitate
participation from around the globe!

3. Uni
fi
es data in motion, data at rest and
computations from embedded
microcontrollers up to data centres
Provides a location-transparent API for high
performance pub/sub and distributed queries
across heterogeneous systems
Facilitates geo-distributed storage and
integration with third party technology in a
plug-and-play fashion

4. Runs everywhere
Native libraries and API bindings for many
programming languages
Over various network technologies: from
transport layer to data link
On embedded and constrained devices
Data Link
Network
Transport
Physical
…

5. Any topology
Peer-to-peer
Clique and mesh topologies
Brokered
Clients communicate
through a router or a peer
Routed
Routers forward data to and
from peers and clients
Clique
Mesh
Router
Router
Router
Router
Peer
Peer
Peer
Peer
Peer
Peer
Peer Peer
Peer
Client
Client
Client
Client
Brokered
Routed

6. SSE
…
Extensible
Enhance zenoh with plugins
Interact with other technologies
…

7. Get your API

8. COTS and embedded
devices
x86 and ARM targets
Native libraries and
bindings
Zenoh API
Rust
• Native library
• Async support
Python
• Binding based on
Rust library
C
• Binding based on
Rust library
• Native library with
zenoh-pico
Coming soon…
API bindings:
• C++
• Java
• …

9. https://github.com/eclipse-zenoh/
zenoh
Rust
# Stable
[dependencies]
zenoh = "0.6.0-beta.1"
# Nightly
[dependencies]
zenoh = { git = "https://github.com/
eclipse-zenoh/zenoh.git" }

10. https://github.com/eclipse-zenoh/
zenoh-python
Python
$ pip install eclipse-zenoh
$ pip install eclipse-zenoh-nightly

11. Let’s write our first Zenoh app

12. Distribute values published on a given key expression to all the
subscribers matching that speci
fi
c key expression
Pub/sub, what for?
MATCHING
NOT MATCHING
(room/kitchen/temp, 21.5)
room/kitchen/*
home/alarm/status
room/kitchen/temp
room/**/temp
MATCHING
MATCHING
PUB
SUBS
The temp now is: 21.5

13. Python examples: https://github.com/eclipse-zenoh/
zenoh-python/tree/master/examples

14. Zenoh carries some
metadata information
related to the encoding of
the value to facilitate
decoding
Encoding

15. Python examples: https://github.com/eclipse-zenoh/
zenoh-python/tree/master/examples

16. Peer-to-peer is a
communication model
where zenoh peers talk
directly with each other
without the intervention of
any zenoh infrastructure
What is
peer-to-peer?

17. Zenoh performs scouting
to discover who is around,
e.g. other routers or peers
Scouting can be based on
multicast, DNS, etc.
What is
scouting?
Peer
multicast
network
Who is
there?
It’s XXX!
Reach me at IP A.
It’s YYY!
Reach me at IP B.
Router
Client

18. Request on-demand some values via a distributed query
matching a given key expression
Query/reply, what for?
MATCHING
NOT MATCHING
room/bedroom/temp
home/alarm/status
room/kitchen/temp
room/bathroom/temp
MATCHING
MATCHING
GET
QUERYABLES
What is the
temp now?
room/*/temp
The temp now is: 25
The temp now is: 21
The temp now is: 27

19. Rust examples: https://github.com/eclipse-zenoh/
zenoh/tree/master/examples

20. The temp now is: 21.5
What is the
latest temp?
Latest temp
is: 21.5
Store data as soon as it is published and allow to retrieve it on-
demand. It is a combination of a subscriber and a queryable.
Distributed storage, what for?
(room/kitchen/temp, 21.5)
PUB
room/*/temp
SUB QUERYABLE
room/*/temp
GET
room/*/temp

21. Rust examples: https://github.com/eclipse-zenoh/
zenoh/tree/master/examples
Subscriber
Queryable

22. All replies produced by the matching queryables are sent
back to the querier

26. routed?
routing

27. Stable
Nightly
Install zenohd from Deb
Stable
Install zenohd from Eclipse
Install zenohd from source
$ git clone https://github.com/eclipse-zenoh/
zenoh.git
$ cd zenoh
$ cargo build --release --all-targets
# The compiled zenohd can be found at:
# ./target/release/zenohd
Install zenohd from Docker
$ docker pull eclipse/zenoh:latest
$ docker pull eclipse/zenoh:master
$ echo "deb [trusted=yes] https://
download.eclipse.org/zenoh/zenoh/latest/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
$ sudo apt update
$ sudo apt install zenoh
Stable Nightly
https://download.eclipse.org/zenoh/zenoh/latest/

28. Peer
Local comm stays peer-to-peer
Remote comm via the zenoh router
All comm via the zenoh router
Client
Router
Peer
Peer
Peer
Peer
Router
Client
Client
Client Client

29. Changing the communication model in Zenoh does NOT require
changing the application logic nor the usage of a di
ff
erent API
It is enough to:
• Have at least one zenoh router up and running in the system
• Set the mode to “peer” / “client” in the application
From peer-to-peer to routed

30. let mut conf = Config::default();
config.set_mode(Some(WhatAmI::Client));
// Or WhatAmI::Peer
config.connect.endpoints.push(
"tcp/localhost:7447".parse().unwrap());
config.listen.endpoints.push(
"tcp/localhost:7448".parse().unwrap());
config.scouting.multicast.set_enabled(Some(false));
config = zenoh.Config.from_json5({
"mode": "client", // Or "peer"
"connect": { "endpoints":
[ "tcp/localhost:7447" ] },
"listen": { "endpoints":
[ "tcp/localhost:7449" ] },
"scouting": {
"multicast": { "enabled": false } }
})
Con
fi
g
fi
le
Rust
Python
{
"mode": “client", // Or "peer"
"connect": { "endpoints":
[ "tcp/localhost:7447" ] },
"listen": { "endpoints":
[ "tcp/localhost:7449" ] },
"scouting": {
"multicast": { "enabled": false } }
}
-l, --listen <ENDPOINT>...
Endpoints to listen on for incoming sessions.
Only peers and routers listen for incoming
sessions.
-e, --connect <ENDPOINT>...
Endpoints to connect to. Clients, peers, and
routers will try to open a session with the
provided list of endpoints.
--no-multicast-scouting
Disable multicast scouting for automatic
discovery and connection in a LAN.
No changes to
the code with a
config file!

31. Con
fi
guration from CLI Con
fi
guration from
fi
le
-l, --listen <ENDPOINT>...
An endpoint on which this router will listen
on for incoming sessions. Repeat this option
to open several listeners.
-e, --connect <ENDPOINT>...
An endpoint this router will try to
connect to. Repeat this option to connect to
several routers.
(router 1)$ zenohd -l tcp/localhost:7447
(router 2)$ zenohd -l tcp/localhost:7448
--rest-http-port 8001 -e tcp/localhost:7447
// conf1.json5
{
mode: "router",
listen: { endpoints: [ "tcp/localhost:7447" ] },
plugins: { rest: { http_port: 8000, }, },
}
// conf2.json5
{
mode: "router",
listen: { endpoints: [ "tcp/localhost:7448" ] },
connect: { endpoints: [ "tcp/localhost:7447" ] },
plugins: { rest: { http_port: 8001, }, },
}
(router 1)$ zenohd -c conf1.json5
(router 2)$ zenohd -c conf2.json5
Default config: https://github.com/eclipse-zenoh/zenoh/blob/master/DEFAULT_CONFIG.json5
$ zenohd --help

32. If the router goes down,
only the client subscriber
will stop receiving data
If the router comes back,
the client will reconnect
and resume receiving data
Example 1:
Pub/Sub
Router
Peer
Peer
Client
PUB
SUB
SUB

33. Connect two routers: one
on a local machine and
one on the cloud
Queries received from the
routed on the cloud are
forwarded downstream
Example 2:
Query/Reply
Router
Peer Peer
Router
http://demo.zenoh.io:8000/room/**
STORAGE QUERYABLE
GET

34. Plugins and backends

35. • Carries DDS tra
ffi
c on top of Zenoh
• Transparent to DDS participants
• Maps Zenoh to HTTP methods
• It support HTML5 Server Sent Events
• Built-in zenoh router
Webserver
DDS
MQTT
https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
REST
• Serves web content (e.g., pages) that
is stored in Zenoh storages
• Carries MQTT tra
ffi
c on top of Zenoh
• Transparent to MQTT clients
https://github.com/eclipse-zenoh/zenoh-plugin-dds
Plugins
https://github.com/eclipse-zenoh/zenoh-plugin-
webserver

36. • A volatile key-value store
• Useful for last-value fast caching
• Built-in zenoh router
• A geo-distributed key-value store
• Alignment of decentralised storages
• Built-in zenoh router
• Multiple backends
In-memory
Filesystem
Storage plugin
• A persistent key-value store
• Useful for serving large
fi
les (e.g. CDN)
Storage and backends
https://github.com/eclipse-zenoh/zenoh-backend-filesystem

37. • A persistent database for time series
• Useful for performing data analytics
Amazon S3
And many more to come…
In
fl
uxDB
• Out-of-the box integration with cloud
storage
https://github.com/eclipse-zenoh/zenoh-backend-influxdb
Storage and backends
• A persistent key-value store
• Useful for last-value persistence
RocksDB
https://github.com/eclipse-zenoh/zenoh-backend-rocksdb
https://github.com/eclipse-zenoh/zenoh-backend-s3

38. Don’t forget to visit
Zenoh’s website…
https://zenoh.io/
… Zenoh’s GitHub …
https://github.com/
eclipse-zenoh/zenoh
… and to join Zenoh’s
Discord server!
https://discord.gg/
2GJ958VuHs

39. Luca Cominardi, PhD
Product conductor
Thank You