https://github.com/robpacheco/dok-stateful-kube https://go.dok.community/slack https://dok.community/ ABSTRACT OF THE TALK Modern web applications are typically comprised of multiple services which utilize storage in a variety of ways. Utilizing storage in Kubernetes introduces challenges that are not obvious while developing locally. We’ll introduce these challenges and show good and bad ways to handle them. We’ll dive into the details of an application along with its deployment in Kubernetes to understand why certain storage patterns are problematic and how they can be modified to behave well in a Kubernetes-based deployment. BIO Rob Pacheco is currently leading cloud operations at Rumble. Prior to Rumble, Rob spent time at Vision Government Solutions as well as Black Duck Software re-architecting, securing, and containerizing its products to run within containerized environments, including Kubernetes and Google Kubernetes Engine. Rob is also the author of the liveProject “Creating and Managing Cloud Native Services in Kubernetes”, and the upcoming liveVideo “Surviving Kubernetes Deployments as an Application Developer” KEY TAKE-AWAYS FROM THE TALK * Behavior stateful primitives in Kubernetes * Common storage patterns in web applications * Patterns for well-behaved storage in a Kubernetes cluster

1. Developing
Stateful
Application on
Kubernetes

2. About Rob

3. Target Audience
APPLICATIONS DEVELOPERS WRITING
SERVICES THAT ARE DEPLOYED TO
KUBERNETES
KUBERNETES OPERATORS HELPING TO
GUIDE APPLICATION AND SERVICE
ARCHITECTURE

4. What We’ll
Talk About
What are stateful application?
Why run stateful applications in
Kubernetes?
Kubernetes persistent storage
mechanisms
Alternatives to storing state in
Kubernetes
Impacts on stateful applications

5. What are
Stateful
Applications
Almost Everything
• Shopping Carts
• Banking
Application
• Security Scanners
Stateless Services
vs. Stateful Services
• Does a service
need to
remember data?
• Can a service
move around a
cluster easily?
Where is Data
stored?
• Filesystem
• Database
• Cloud Service

6. Persisting State in Kubernetes

7. Difficulties with Volumes
Volumes may be
attached directly to
a node
Volumes may not
support multiple
writers
Replicated services
typically have their
own volumes

8. Alternatives to State in Kubernetes
Hosted Redis
Amazon EC2
Amazon S3
Amazon RDS

9. Action