Technology · Ebook

Koordinator: QoS-Based Scheduling and Colocation for Kubernetes

by Shriira Press

Koordinator is a CNCF sandbox scheduling system that lets microservices, web services, AI training, and big data jobs share the same Kubernetes nodes safely, raising cluster utilization without sacrificing the latency of critical workloads. It runs alongside vanilla Kubernetes — no forked kubelet or patched API server — and adds a two-dimensional priority-and-QoS model, dynamic resource overcommitment that reclaims allocated-but-idle capacity for batch pods, fine-grained CPU and NUMA orchestration, load-aware scheduling and descheduling, gang scheduling, and multi-tenant elastic quotas. This free book builds the picture from the ground up: the utilization problem and colocation, priority and QoS classes, the architecture of koord-manager, koord-scheduler, koord-descheduler, and the koordlet node agent, then overcommitment, batch colocation, CPU orchestration, load-aware placement, job scheduling, and putting it all together in practice.

Contents

1. 1Preface
2. 2Chapter 1 — What Koordinator Is
3. 3Chapter 2 — Priority and QoS
4. 4Chapter 3 — Architecture
5. 5Chapter 4 — Dynamic Resource Overcommitment
6. 6Chapter 5 — Colocating Batch Workloads
7. 7Chapter 6 — Fine-Grained CPU Orchestration
8. 8Chapter 7 — Load-Aware Scheduling and Descheduling
9. 9Chapter 8 — Gang Scheduling and Elastic Quota
10. 10Chapter 9 — Koordinator in Practice