Kubernetes
Kubernetes Cluster Planning: Scale and Node Size
· β˜• 1 min read
Judging from the survey data, more people lean toward choosing small clusters. Below is a comparison list from the perspective of node count and node configuration. Below is a comparison of choosing a few large clusters versus many small clusters: Feature A few large clusters Many small clusters Resource utilization High Low Node management overhead Low High Resource scaling range Large Small Resource scheduling range Large Small Efficiency of inter-application communication High Low Cluster operations difficulty High Low Cluster version diversity Low High Blast radius Large Small Below is a comparison of choosing a few high-spec nodes versus many low-spec nodes:

Building Two Places and Three Centers Under Containers
· β˜• 6 min read
1. About Two Places and Three Centers As shown above, the two-places-three-centers architecture exists to improve the fault tolerance and disaster recovery capability of a system. When one data center becomes unavailable, traffic for critical business can be switched to another data center, which makes the system resilient to city-level natural disasters.

Multi-Cluster Applications Under Kubevela
· β˜• 10 min read
Kubevela is currently at version 1.1. We usually consider 1.x releases to be relatively stable and safe to try in production. Through continuous tracking and learning, I have also come to appreciate some of the things Kubevela does well. This is a summary document. 1. What Problem Kubevela Solves Aimed at platform developers Several roles need to be distinguished: development, operations, and operations development.

Replacing Calico with Cilium
· β˜• 2 min read
1. System Requirements Kubernetes, >= 1.16.0-0 Helm, >= 3.0 Linux kernel >= 4.9.17 For the process of upgrading the kernel on CentOS 7, see How to Switch the Data Plane to eBPF Under Calico. 2. Uninstalling Calico Delete the cluster resources 1 2 3 4 5 6 kubectl -n kube-system delete ds calico-node kubectl -n kube-system delete deploy calico-kube-controllers kubectl -n kube-system delete sa calico-node kubectl -n kube-system delete sa calico-kube-controllers kubectl -n kube-system delete cm calico-config kubectl -n kube-system delete secret calico-config 1 kubectl get crd | grep calico | awk '{print $1}' | xargs kubectl delete crd Bring down the Tunl0 interface 1 ifconfig tunl0 down Remove the Calico configuration files 1 rm -rf /etc/cni/net.

How to Switch the Data Plane to eBPF Under Calico
· β˜• 2 min read
1. Environment Preparation 1.1 Calico eBPF Requirements System requirements Ubuntu 18.04.4+ Red Hat v8.2 Linux kernel v5.3+ If Calico does not detect a compatible kernel, it falls back to standard mode. Every node needs a BPF filesystem mounted at /sys/fs/bpf Calico version no lower than 3.13 1.2 Upgrading the Kernel This uses CentOS 7: