Traffic management with Istio in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Istio in the context of Kubernetes?

Istio is a service mesh that helps manage, secure, and observe traffic between microservices in Kubernetes clusters without changing application code.

beginner

What is a VirtualService in Istio?

A VirtualService defines how requests are routed to services within the mesh, allowing control over traffic routing rules like splitting, retries, and timeouts.

intermediate

How does Istio perform traffic splitting?

Istio splits traffic by defining weights in a VirtualService, sending a percentage of requests to different versions of a service for gradual rollouts or A/B testing.

intermediate

What is the purpose of DestinationRule in Istio?

DestinationRule configures policies for traffic to a service after routing, such as load balancing, connection pool settings, and circuit breakers.

advanced

How can Istio help with fault injection?

Istio can simulate failures like delays or aborts in service responses to test the resilience of applications using fault injection rules in VirtualService.

What Istio resource defines routing rules for directing traffic to different service versions?

A VirtualService

B DestinationRule

C Gateway

D ServiceEntry

VirtualService controls how requests are routed to different service versions.

Which Istio feature allows sending 20% of traffic to a new service version and 80% to the old one?

A Fault Injection

B Traffic Splitting

C Load Balancing

D Circuit Breaking

Traffic Splitting uses weights in VirtualService to divide traffic percentages.

What does a DestinationRule configure in Istio?

A Routing rules for incoming traffic

B Service discovery entries

C Policies like load balancing and connection pools for traffic after routing

D Ingress gateway settings

DestinationRule sets policies for traffic after routing, such as load balancing.

How does Istio help test application resilience?

A By injecting faults like delays or errors

B By automatically scaling pods

C By encrypting traffic

D By monitoring CPU usage

Istio can inject faults to simulate failures and test resilience.

Which Istio resource is used to expose services outside the mesh?

A Sidecar

B VirtualService

C DestinationRule

D Gateway

Gateway manages inbound and outbound traffic to/from the mesh.

Explain how Istio manages traffic routing between different versions of a service.

Think about how you can send some users to a new version while others stay on the old one.

Describe the role of DestinationRule in Istio traffic management.

It controls what happens after traffic is routed to a service.