Improve etcd capacity on dedicated Kubernetes clusters

Dedicated Kubernetes clusters use etcd v3.3.8 by default, which supports a backend database of up to 2 GB in size. A cluster can no longer write to etcd if more than 2 GB of data is stored in etcd. This topic describes how to upgrade etcd to v3.4.3. This improves etcd capacity on dedicated Kubernetes clusters.

1. Use SSH to log on to the master nodes where etcd is installed and verify that the current etcd version is 3.3.8.
2. Run the following shell script to download etcd-v3.4.3 binary and start the new version.
   Note

   • Perform the upgrade on each node. Make sure that you wait until the newly upgraded node has a Ready status before you move on to the next one.
   • etcd supports high availability. You can still access etcd during the upgrade.

   #! /usr/bin/env bash
   
   etcdbin=http://aliacs-k8s-cn-hangzhou.oss.aliyuncs.com/etcd/etcd-v3.4.3/etcd
   etcdctlbin=http://aliacs-k8s-cn-hangzhou.oss.aliyuncs.com/etcd/etcd-v3.4.3/etcdctl
   
   function download(){
       wget -O etcd ${etcdbin}
       wget -O etcdctl ${etcdctlbin}
       chmod +x {etcd,etcdctl}
       mv etcd /usr/bin/etcd
       mv etcdctl /usr/bin/etcdctl
       etcd --version
   }
   
   function config() {
       ETCD_FILE=/lib/systemd/system/etcd.service
       sed -i "/ETCD_EXPERIMENTAL_BACKEND_BBOLT_FREELIST_TYPE/ d" ${ETCD_FILE}
       sed -i "/ETCD_QUOTA_BACKEND_BYTES/ d" ${ETCD_FILE}
       sed -i "/^\[Service\]/a\Environment=\"ETCD_EXPERIMENTAL_BACKEND_BBOLT_FREELIST_TYPE=map\"" ${ETCD_FILE}
       sed -i "/^\[Service\]/a\Environment=\"ETCD_QUOTA_BACKEND_BYTES=100000000000\"" ${ETCD_FILE}
       sed -i "s/initial-cluster-state new/initial-cluster-state existing/g" ${ETCD_FILE}
   
       systemctl daemon-reload
       systemctl restart etcd
   }
   
   download; config
   
   ENDPOINTS=`ps -eaf|grep etcd-servers|grep -v grep|awk -F "=" '{print $22}'|awk -F " " '{print $1}'`
   
   ETCDCTL_API=3 etcdctl \
           --endpoints=${ENDPOINTS}         \
           --cacert=/var/lib/etcd/cert/ca.pem         \
           --cert=/var/lib/etcd/cert/etcd-client.pem         \
           --key=/var/lib/etcd/cert/etcd-client-key.pem \
           member list

3. Run the following command to check whether etcd processes are running.

   ps aux|grep etcd

#ETCDCTL_API=3 etcdctl --endpoints=${ENDPOINTS} \
      --cacert=/var/lib/etcd/cert/ca.pem \
      --cert=/var/lib/etcd/cert/etcd-client.pem \
      --key=/var/lib/etcd/cert/etcd-client-key.pem endpoint health

$ENDPOINTS is healthy