Kubernetes

The Horizontal Pod Autoscaler (HPA) in Kubernetes automatically scales the number of pods in a deployment or replica set based on observed resource usage, such as CPU or memory. This article breaks down how HPA works, when to use it, its pros and cons, and how to get started with it in your Kubernetes cluster. 1. What is HPA? HPA dynamically adjusts the number of pods in a Kubernetes workload (like a Deployment or StatefulSet) based on metrics from the Kubernetes Metrics Server. ...

Kubernetes Resource Management: LimitRange vs ResourceQuota Managing resources in Kubernetes is critical for ensuring fair usage, stability, and predictable performance in a multi-tenant cluster. Two powerful tools provided by Kubernetes for this purpose are LimitRange and ResourceQuota. This article explains what they are, their differences, and how to use them effectively. What is LimitRange? LimitRange is a Kubernetes policy object that sets default resource limits (CPU/memory) for containers in a namespace. ...

Deploying applications to Kubernetes? Follow these best practices to avoid downtime, improve scalability, and simplify operations. 1. Use Readiness and Liveness Probes Probes help Kubernetes know when your app is healthy and ready to serve traffic. livenessProbe: httpGet: path: /healthz port: 8080 initialDelaySeconds: 5 periodSeconds: 10 readinessProbe: httpGet: path: /ready port: 8080 initialDelaySeconds: 5 periodSeconds: 10 2. Configure Resource Requests and Limits Avoid over/under-scheduling: ...

Common Ingress Errors in Kubernetes Ingress is a powerful Kubernetes resource that manages external access to services within your cluster. However, it often becomes a source of confusion and frustration due to misconfigurations or overlooked details. This article outlines the most common Ingress errors and how to fix them. 1. Misconfigured Annotations Annotations can control features like URL rewrites, authentication, and rate limiting. Incorrect annotations may silently break your setup. ...

Kubernetes supports two main kube-proxy modes: iptables and ipvs. Which one should you use? 1. What is kube-proxy? kube-proxy manages network rules on Kubernetes nodes, allowing communication between services and pods. It can operate in different modes: iptables, ipvs, and userspace (deprecated). 2. iptables Mode Default and widely supported Implements rules using iptables NAT chains Pros: Simpler No extra kernel modules required Easier to debug Cons: Performance degrades with many services Sequential rule processing 3. IPVS Mode Based on Linux IP Virtual Server (part of LVS) Uses a hash table for rules → faster performance Pros: Better performance for large-scale clusters Supports connection-level load balancing algorithms (round-robin, least connections, etc.) Cons: Requires ip_vs kernel modules Slightly more complex setup 4. Switching to IPVS Check kernel support: ...