The document discusses NATS, a lightweight, high-performance messaging system designed for building distributed applications, highlighting its core features and benefits including low latency, cross-cloud operability, and a strong community. It covers aspects such as decentralized authentication, message persistence through Jetstream, and use cases for subject mapping in modern applications. The content also includes insights from Siddharth Jain and Sourabh Agrawal, experts in the field, along with references to additional resources for further exploration.

2. How many of you have used messaging system?
How many of you know about NATS ?
Pulsar ?
Red Panda ?
Kafka ?
ActiveMQ ? RabittMQ ?

3. Siddharth Jain
Senior Staff at Nutanix
Sourabh Agrawal
MTS-4 at Nutanix
Ø Distributed System Enthusiast
Ø SME For Pulsar & NATS
Ø Decade of experience with apps,
infra & cloud
Ø Software architect with two decades of
experience
Ø Excited about:
ü Distributed Systems
ü Security
ü Non-functional aspects of systems
linkedin.com/in/siddharth-jain-4725bb19/
linkedin.com/in/sourabhaggrawal/
slideshare.net/souravagrawal35
https://github.com/souravagrawal

5. What we love about NATS ?
• Developed in GO
• Configure only what you need
• Cross cloud, cross geo and extended to edge
• Single digit millisecond latency
• Only one binary to run
• Active Community on
slack
• Open-Sourced

6. Why should you care ?
• CNCF Project
• Over 40 client language implementations
• Github: 11.2K Stars, 1.1K forks
• 10+Years of consistent development

7. What is NATS ?
• NATS is “Open Sourced, Apache Licensed” lightweight and high-
performance messaging system designed for building distributed and scalable
applications. NATS simple ecosystem is what makes it stand apart from
other. It’s a client-server system with a massive performant and horizontally
scalable server component.
cclient
client
server

8. Core NATS
• NATS started its journey with Core NATS, where you can publish/subscribe
to a subject, but the messages are “not persisted” and only active subscriber
will receive the message. In case if consumer is not active it loses the
message, so NATS core follows “At most once delivery”.

9. Core NATS

10. Core NATS
Load Distribution with
Queue Groups

11. Jetstream
PERSISTENT
MESSAGING
DURABILITY &
HIGH
AVAILABILITY
EFFICIENT
STREAMING
KV STORE OBJECT STORE EASE OF USE AT LEAST ONCE
DELIVERY

12. Subject-1
Subject-2
Stream
Nats-server
Streams

13. Streams Replication &
Placement
R1
R2
R3
NATS Cluster
- File/Memory Storage
- Configure replicas
- RAFT protocol for
consensus
- configuration for multiple
usescases

14. Streams Source &
Mirroring
R2 R3
R1
R1
R1
eu-west-1
eu-north-1
eu-east-1

15. Subject-1
Consumer
Stream
Consumer
Nats-server

16. Subject-1
Consumer
Stream
Consumer
VM/POD
Subject-1
Consumer
Stream
VM/POD
Subject-1
Consumer
Stream
VM/POD
- Message Replay
- Direct Get Api
- Ephemeral/Durable consumer
- File/Memory storage
- RAFT protocol for consensus

17. NATS Subject Mapping
- SUBJECT
PARITIONING
- CANARY
DEPLOYMENTS
- A/B TESTING - CHAOS
TESTING
- SUBJECT
MIGRATION
usecases that can be solved using

18. NATS
Subject
Mapping

19. Decentralised Auth
• Server has no idea who the users are, just what accounts exist
• Clients have a JWT with the public and private key
• Authentication requests are not vulnerable to playback attack
• Deployment can have different authorities for different parts of the system
• Chain of trust:
• Each level is authorized to do something different
• Operators – Creates accounts
• Accounts – Creates users
• Users – Creates streams/subjects, publish messages

20. Operator
Account
User
Account
User User User
NATS
NATS NATS
What gets stored ?
- Account & Operator JWTS
what does not get stored ?
- User JWTs
- Private Keys
Allow/deny pub
Allow deby sub
limits
Client Server
Info { nonce: …}
CONNECT {jwt: …, sig: …}
Is this sig valid ?
Is this jwt valid ?
was it signed by account I own
?
Did the operator sign the jwt ?
CONNECTING …
Decentralized Auth
Hierarchy

21. NATS Clustering
Unlike core NATS clustering though, each JetStream node must specify a server name and cluster name.
•# Server A - the 'seed server'
•$ nats-server -p 4222 -cluster nats://localhost:4248 --cluster_name test-cluster
•# Server B
•$ nats-server -p 5222 --cluster nats://localhost: 5248 --routes nats://localhost:4248 --cluster_name test-cluster
•# Server C
•$ nats-server -p 6222 --cluster nats://localhost:6248 --routes nats://localhost:4248 --cluster_name test-cluster

22. Leaf Node
Bridge 2 NATS
System
Extending a hub
(hub & spoke)
Connectivity at the
edge

23. NATS
Supercluster
Cluster of clusters
Use gateway connection to minimise
connectivity requirement
Planet scale
Great for data sovereignty without
restricting access for business requirements
Can make use of queue group for load
balanced response closest to user

24. node
C
C C
Europe
Us East Us West
node
node node node
node
node
node
node
node

25. NATS KV
Jetstream, the persistence layer of NATS, doesn't just allow for higher qualities
of service and features associated with 'streaming', but it also enables some
functionalities not found in messaging systems.
One such feature is the Key/Value store functionality, which allows client
applications to create 'buckets' and use them as immediately (as opposed to
eventually) consistent, persistent associative arrays.

26. Strength & Challenges
• Mirror stream is changing the game in messaging.
You can achieve low latency application using
memory based stream and persist its data using
mirror stream.
• Source stream can be used to aggregate data from
multiple streams, saving you the headache of
writing application to consumer from all stream
then aggregate.
• Every stream and consumer create their own
RAFT Group, which increases network
bandwidth consumption if you have many.

27. #we open-source

28. #we open-source

29. 8
PRs
6
issues
#we open-source

30. Nats@Nutanix
• Multi-Tenant Nats Cluster in cloud
• 260+ R3 file streams
• 260+ R3 file durable consumers
• Implemented
• Nats Manager for cluster admin task and monitoring
• DR Service for periodic data snapshot

31. Nats@Nutanix
• Running on Nutanix management VM
o Integration with Nutanix process manager to run Nats container
• Running with resource constraints
o Used Nats global as well as per subject limits for resource governance
• Running on k8s cluster
o Used config maps and helm charts for easy integration

32. Nats@Nutanix
• New features and bugs!
o Great community support, Quick responses
• Enterprise product release management
o Upgrade at a cadence of ~6 months

33. References
- https://www.youtube.com/watch?v=0ZQsjVKvtTU
- https://docs.nats.io/
- https://natsbyexample.com/examples
-https://www.youtube.com/@SynadiaCommunications
https://twitter.com/nats_io
https://groups.google.com/forum/#!forum/natsio
https://slack.nats.io/

34. Thank You
Siddharth Jain
Senior Staff at Nutanix
Sourabh Agrawal
MTS-4 at Nutanix
linkedin.com/in/siddharth-jain-4725bb19/ linkedin.com/in/sourabhaggrawal/
slideshare.net/souravagrawal35
github.com/souravagrawal