This document summarizes a presentation about Kubernetes Event-driven Autoscaling (KEDA). KEDA allows applications running on Kubernetes to automatically scale based on external events from services like Azure Event Hubs, Kafka, or Cosmos DB. It provides out-of-the-box and custom scalers to monitor event sources and scale deployments and jobs as needed. KEDA is open source, cloud agnostic, and aims to simplify autoscaling so developers can focus on their applications rather than scaling internals. The presenters demonstrate using KEDA to scale a .NET Core worker based on an Azure Service Bus queue depth.

1. Application Autoscaling Made Easy
with Kubernetes Event-Driven
Autoscaling (KEDA)
Jeff Hollan, Microsoft, Principal Product Manager Azure Functions
Tom Kerkhove, Codit, Azure Architect and Microsoft MVP
1

2. Jeff Hollan
Principle Program Manager at Microsoft
KEDA maintainer
2
Tom Kerkhove
Azure Architect at Codit, Microsoft MVP
KEDA maintainer

3. Agenda
| Serverless and Kubernetes
| Application autoscaling made simple
with KEDA
| How does it work?
| Roadmap
| Q&A
3

4. How we see serverless used?
4
Automation “Glue” between
services
Rapid APIs Event Stream and
Queue processing

5. Event Hub
/ Kafka
CosmosDB
/ Mongo
• Must be able to
scale to billions of
events
• If an error occurs,
Kafka should retry /
not checkpoint
• Cost optimization is
high-pri
• Ordering must be
preserved

6. Serverless and Kubernetes
USE ‘SERVERLESS’ ON-
PREMISES
LEVERAGING EXISTING
KUBERNETES
INVESTMENTS
CUSTOM COMPUTE,
SECURITY, OR NETWORK
REQUIREMENTS
NO VENDOR LOCK-IN

7. 7
So, how do you scale on Kubernetes?

8. 8
8
Node 1
Cluster
Node 2 Node 3
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Custom Metric
Provider
Horizontal Pod
Autoscaler(s)
Cluster
Autoscaler

9. Autoscaling based on external sources
9

10. Application autoscaling made simple with
Kubernetes Event-driven Autoscaling ( )
10
| Automatically scale Deployments & Jobs
| Vendor-Agnostic & Built-in Scalers
| Production-grade Authentication
| Save resources with scale to 0
| Run Azure Functions anywhere (simple & durable)
| Started as a partnership between Microsoft & Red Hat
| Focus on your app scaling, not the scaling internals

11. 11
KEDA is cloud-agnostic & vendor-neutral
KEDA is cloud-agnostic & vendor-neutral

12. Demo
Autoscaling .NET Core worker based on Azure Service Bus queue depth
12

13. How does it work?
13
| KEDA is built on top of Kubernetes
| Manages workloads to provide scale to 0
| Registers itself as a metric adapter
| Provides metrics for HPA to scale on
| Out-of-the-box & add-on scalers
| Easy to install
| With Helm
| https://hub.helm.sh/charts/kedacore/keda
| With Operator Framework
| https://operatorhub.io/operator/keda

14. 14

15. 15

16. 16
16
Node 1 Node 2 Node 3
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Pod
Cluster
Autoscaler
Custom Metric
Provider
Horizontal Pod
Autoscaler(s)
Cluster

17. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers

18. Kubernetes Cluster
Event Source
KEDA Operator Metrics API HPA
Scalers

19. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers
Deployment
ScaledObject.yaml
Event Source

20. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers
Deployment
ScaledObject.yaml
Event Source

21. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers
Event Source Deployment
ScaledObject.yaml

22. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers
Event Source Deployment
ScaledObject.yaml
How many events are
being generated?

23. Kubernetes Cluster
KEDA Operator Metrics API HPA
Scalers
Event Source Deployment
ScaledObject.yaml
How many events are
being generated?

24. Kubernetes Cluster
KEDA Operator Metrics API
Deployment
HPA
Deployment
Scalers
Event Source Deployment
ScaledObject.yaml
How many events are
being generated?

25. Community
25
| 1.8k stars on GitHub
| 50 contributors, incl.
| Microsoft
| Red Hat
| IBM
| Codit
| BUPA
| Astronomer.io
| Bi-weekly community standups
| https://keda.sh

26. Microsoft Kubernetes

27. Benefits of using Azure Functions with KEDA
27
| Brings an event driven *programming model* to KEDA event driven scale
| Same productive developer tooling and experience
| Any function app can be put in a container and scaled with KEDA
| Azure Functions is already open sourced – but are doing more and
considering branding to make that more apparent

28. Roadmap
28
| We are donating KEDA to Cloud Native Computing Foundation (CNCF) as
Sandbox project
| Seamless integration with Knative
| Introduce new scalers
| Azure Monitor
| Service Mesh Interface (SMI)
| Azure IoT Hub
| What do you need?

29. Q&A
29