KEDA 2.8: Expanded Autoscaling with New Scalers

Introduction

KEDA 2.8, released on September 20, 2022, continues the evolution of event-driven autoscaling for Kubernetes. This release introduces new scalers, improves the HTTP add-on, and enhances observability, making KEDA an even more powerful solution for scaling workloads based on external events.

This release is most relevant in day‑2 operations—when you’re upgrading, scaling, or troubleshooting in real clusters. The goal is the same: fewer surprises and more predictable behavior under load.

New Scalers & Triggers

• Redis Streams scaler enables autoscaling based on message queue depth in Redis Streams.
• Azure Log Analytics scaler provides scaling based on query results from Azure Log Analytics.
• PostgreSQL scaler supports scaling based on query results from PostgreSQL databases.
• MongoDB scaler enables autoscaling based on MongoDB collection metrics.

HTTP Add-On Improvements

1. Request queue scaling enhancements improve accuracy of scaling decisions based on HTTP request queue depth.
2. Multi-tenant support enables isolated scaling for different applications sharing the same HTTP endpoint.
3. Custom metrics support allows scaling based on application-specific HTTP metrics.
4. Rate limiting integration provides more sophisticated scaling strategies for HTTP workloads.

Observability & Monitoring

• Metrics expansion exposes detailed scaling metrics including trigger values, replica counts, and scaling events.
• Prometheus integration provides comprehensive metrics for dashboards and alerting.
• Event logging improvements provide better visibility into scaling decisions and trigger evaluations.
• Health checks ensure KEDA scalers are functioning correctly with detailed status reporting.

Performance & Reliability

• Scaler performance optimizations reduce latency in trigger evaluation and scaling decisions.
• Concurrent scaling improvements enable better handling of multiple ScaledObjects in large clusters.
• Error recovery enhancements provide automatic retry for transient scaler failures.
• Resource efficiency optimizations reduce KEDA operator resource usage.

Operational Enhancements

• Helm chart improvements simplify installation and upgrades with better default values.
• Documentation expansion includes comprehensive guides for all scalers and common use cases.
• Migration tools simplify upgrades from earlier KEDA versions.
• Community growth demonstrates widespread adoption and active development.

Getting Started

kubectl apply -f https://github.com/kedacore/keda/releases/download/v2.8.0/keda-2.8.0.yaml

Create a ScaledObject:

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: redis-scaledobject
spec:
  scaleTargetRef:
    name: worker-deployment
  minReplicaCount: 1
  maxReplicaCount: 10
  triggers:
  - type: redis-streams
    metadata:
      address: redis-service:6379
      stream: my-stream
      consumerGroup: my-consumer-group
      pendingEntriesCount: "5"

Summary

KEDA 2.8 continues to evolve as the standard for event-driven autoscaling, providing teams with powerful tools to scale workloads based on any external event source.