1、前言
Pod调度运⾏时，如果应⽤不需要任何稳定的标示、有序的部署、删除和扩展，则应该使⽤⼀组⽆状态副本的控制器来部署应⽤，例如 Deployment 或 ReplicaSet更适合⽆状态服务需求，⽽StatefulSet适合管理所有有状态的服务，⽐如MySQL、MongoDB集群等。
2、StatefulSet控制器运行MySQL一主多从架构图
StatefulSet本质上是Deployment的⼀种变体，在v1.9版本中已成为GA版本，它为了解决有状态服务的问题，它所管理的Pod拥有固定的Pod名称，启停顺序，在StatefulSet中，Pod名字称为⽹络标识(hostname)，还必须要⽤到共享存储。
在Deployment中，与之对应的服务是service，⽽在StatefulSet中与之对应的headless service，headless service，即⽆头服务，与service的区别就是它没有Cluster IP，解析它的名称时将返回该Headless Service对应的全部Pod的Endpoint列表。
2.1、StatefulSet控制器特点
- 给每个pod分配固定且唯⼀的⽹络标识符
- 给每个pod分配固定且持久化的外部存储
- 对pod进⾏有序的部署和扩展
- 对pod进有序的删除和终⽌
- 对pod进有序的⾃动滚动更新
2.2、StatefulSet的组成部分
- Headless Service：⽤来定义Pod⽹络标识( DNS domain)，指的是短的service(丢失了domainname)。
- StatefulSet：定义具体应⽤，有多少个Pod副本，并为每个Pod定义了⼀个域名。
- volumeClaimTemplates： 存储卷申请模板，创建PVC，指定pvc名称⼤⼩，将⾃动创建pvc，且pvc必须由存储类供应。
3、在k8s上部署mysql一主多从
3.1、基础镜像准备
3.1.1、准备mysql镜像
下载镜像
root@k8s-master01:~# nerdctl pull mysql:5.7.36 修改镜像tag为本地harbor地址
root@k8s-master01:~# nerdctl tag mysql:5.7.36 harbor.ik8s.cc/magedu/mysql:5.7.36 上传镜像至本地harbor
root@k8s-master01:~# nerdctl push harbor.ik8s.cc/magedu/mysql:5.7.36 3.1.2、准备xtrabackup镜像
下载镜像
root@k8s-master01:~# nerdctl pull registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0 修改镜像tag为本地harbor地址
root@k8s-master01:~# nerdctl tag registry.cn-hangzhou.aliyuncs.com/hxpdocker/xtrabackup:1.0 harbor.ik8s.cc/magedu/xtrabackup:1.0 上传镜像至本地harbor
root@k8s-master01:~# nerdctl push harbor.ik8s.cc/magedu/xtrabackup:1.0 3.1.3、验证镜像是否上传至harbor？
3.2、准备pv
3.2.1、在nfs服务器上创建数据存储目录
root@harbor:~# mkdir -pv /data/k8sdata/magedu/mysql-datadir-{1..5} mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-1' mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-2' mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-3' mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-4' mkdir: created directory '/data/k8sdata/magedu/mysql-datadir-5' root@harbor:~# 3.2.2、在nfs服务器上导出数据存储目录
root@harbor:/data/k8sdata/magedu# cat /etc/exports # /etc/exports: the access control list for filesystems which may be exported # to NFS clients. See exports(5). # # Example for NFSv2 and NFSv3: # /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check) # # Example for NFSv4: # /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check) # /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check) # /data/k8sdata/kuboard *(rw,no_root_squash) /data/volumes *(rw,no_root_squash) /pod-vol *(rw,no_root_squash) /data/k8sdata/myserver *(rw,no_root_squash) /data/k8sdata/mysite *(rw,no_root_squash) /data/k8sdata/magedu/images *(rw,no_root_squash) /data/k8sdata/magedu/static *(rw,no_root_squash) /data/k8sdata/magedu/zookeeper-datadir-1 *(rw,no_root_squash) /data/k8sdata/magedu/zookeeper-datadir-2 *(rw,no_root_squash) /data/k8sdata/magedu/zookeeper-datadir-3 *(rw,no_root_squash) /data/k8sdata/magedu/redis-datadir-1 *(rw,no_root_squash) /data/k8sdata/magedu/redis0 *(rw,no_root_squash) /data/k8sdata/magedu/redis1 *(rw,no_root_squash) /data/k8sdata/magedu/redis2 *(rw,no_root_squash) /data/k8sdata/magedu/redis3 *(rw,no_root_squash) /data/k8sdata/magedu/redis4 *(rw,no_root_squash) /data/k8sdata/magedu/redis5 *(rw,no_root_squash) /data/k8sdata/magedu/mysql-datadir-1 *(rw,no_root_squash) /data/k8sdata/magedu/mysql-datadir-2 *(rw,no_root_squash) /data/k8sdata/magedu/mysql-datadir-3 *(rw,no_root_squash) /data/k8sdata/magedu/mysql-datadir-4 *(rw,no_root_squash) /data/k8sdata/magedu/mysql-datadir-5 *(rw,no_root_squash) root@harbor:/data/k8sdata/magedu# exportfs -av exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/kuboard". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [2]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/volumes". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [3]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/pod-vol". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [4]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/myserver". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [5]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/mysite". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [7]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/images". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [8]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/static". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [11]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-1". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [12]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-2". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [13]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/zookeeper-datadir-3". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [16]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis-datadir-1". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [18]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis0". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [19]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis1". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [20]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis2". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [21]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis3". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [22]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis4". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [23]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/redis5". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [27]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-1". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [28]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-2". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [29]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-3". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [30]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-4". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exportfs: /etc/exports [31]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/magedu/mysql-datadir-5". Assuming default behaviour ('no_subtree_check'). NOTE: this default has changed since nfs-utils version 1.0.x exporting *:/data/k8sdata/magedu/mysql-datadir-5 exporting *:/data/k8sdata/magedu/mysql-datadir-4 exporting *:/data/k8sdata/magedu/mysql-datadir-3 exporting *:/data/k8sdata/magedu/mysql-datadir-2 exporting *:/data/k8sdata/magedu/mysql-datadir-1 exporting *:/data/k8sdata/magedu/redis5 exporting *:/data/k8sdata/magedu/redis4 exporting *:/data/k8sdata/magedu/redis3 exporting *:/data/k8sdata/magedu/redis2 exporting *:/data/k8sdata/magedu/redis1 exporting *:/data/k8sdata/magedu/redis0 exporting *:/data/k8sdata/magedu/redis-datadir-1 exporting *:/data/k8sdata/magedu/zookeeper-datadir-3 exporting *:/data/k8sdata/magedu/zookeeper-datadir-2 exporting *:/data/k8sdata/magedu/zookeeper-datadir-1 exporting *:/data/k8sdata/magedu/static exporting *:/data/k8sdata/magedu/images exporting *:/data/k8sdata/mysite exporting *:/data/k8sdata/myserver exporting *:/pod-vol exporting *:/data/volumes exporting *:/data/k8sdata/kuboard root@harbor:/data/k8sdata/magedu# 3.2.2、创建pv
创建pv配置清单
--- apiVersion: v1 kind: PersistentVolume metadata: name: mysql-datadir-1 namespace: magedu spec: capacity: storage: 50Gi accessModes: - ReadWriteOnce nfs: path: /data/k8sdata/magedu/mysql-datadir-1 server: 192.168.0.42 --- apiVersion: v1 kind: PersistentVolume metadata: name: mysql-datadir-2 namespace: magedu spec: capacity: storage: 50Gi accessModes: - ReadWriteOnce nfs: path: /data/k8sdata/magedu/mysql-datadir-2 server: 192.168.0.42 --- apiVersion: v1 kind: PersistentVolume metadata: name: mysql-datadir-3 namespace: magedu spec: capacity: storage: 50Gi accessModes: - ReadWriteOnce nfs: path: /data/k8sdata/magedu/mysql-datadir-3 server: 192.168.0.42 --- apiVersion: v1 kind: PersistentVolume metadata: name: mysql-datadir-4 namespace: magedu spec: capacity: storage: 50Gi accessModes: - ReadWriteOnce nfs: path: /data/k8sdata/magedu/mysql-datadir-4 server: 192.168.0.42 --- apiVersion: v1 kind: PersistentVolume metadata: name: mysql-datadir-5 namespace: magedu spec: capacity: storage: 50Gi accessModes: - ReadWriteOnce nfs: path: /data/k8sdata/magedu/mysql-datadir-5 server: 192.168.0.42 创建pv
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl apply -f pv/mysql-persistentvolume.yaml persistentvolume/mysql-datadir-1 created persistentvolume/mysql-datadir-2 created persistentvolume/mysql-datadir-3 created persistentvolume/mysql-datadir-4 created persistentvolume/mysql-datadir-5 created root@k8s-master01:~/k8s-data/yaml/magedu/mysql# 3.2.3、验证pv
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE mysql-datadir-1 50Gi RWO Retain Available 5s mysql-datadir-2 50Gi RWO Retain Available 5s mysql-datadir-3 50Gi RWO Retain Available 5s mysql-datadir-4 50Gi RWO Retain Available 5s mysql-datadir-5 50Gi RWO Retain Available 5s redis-cluster-pv0 5Gi RWO Retain Bound magedu/data-redis-1 8d redis-cluster-pv1 5Gi RWO Retain Bound magedu/data-redis-3 8d redis-cluster-pv2 5Gi RWO Retain Bound magedu/data-redis-4 8d redis-cluster-pv3 5Gi RWO Retain Bound magedu/data-redis-0 8d redis-cluster-pv4 5Gi RWO Retain Bound magedu/data-redis-5 8d redis-cluster-pv5 5Gi RWO Retain Bound magedu/data-redis-2 8d redis-datadir-pv-1 10Gi RWO Retain Bound magedu/redis-datadir-pvc-1 9d zookeeper-datadir-pv-1 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-1 10d zookeeper-datadir-pv-2 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-2 10d zookeeper-datadir-pv-3 20Gi RWO Retain Bound magedu/zookeeper-datadir-pvc-3 10d root@k8s-master01:~/k8s-data/yaml/magedu/mysql# 3.3、运行mysql服务
MYSQL CONFIGMAP配置清单
apiVersion: v1 kind: ConfigMap metadata: name: mysql namespace: magedu labels: app: mysql data: master.cnf: | # Apply this config only on the master. [mysqld] log-bin log_bin_trust_function_creators=1 lower_case_table_names=1 slave.cnf: | # Apply this config only on slaves. [mysqld] super-read-only log_bin_trust_function_creators=1 MYSQL POD配置清单
apiVersion: apps/v1 kind: StatefulSet metadata: name: mysql namespace: magedu spec: selector: matchLabels: app: mysql serviceName: mysql replicas: 2 template: metadata: labels: app: mysql spec: initContainers: - name: init-mysql #初始化容器1、基于当前pod name匹配角色是master还是slave，并动态生成相对应的配置文件 image: harbor.ik8s.cc/magedu/mysql:5.7.36 command: - bash - "-c" - | set -ex # Generate mysql server-id from pod ordinal index. [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 #匹配hostname的最后一位、最后是一个顺序叠加的整数 ordinal=${BASH_REMATCH[1]} echo [mysqld] > /mnt/conf.d/server-id.cnf # Add an offset to avoid reserved server-id=0 value. echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf # Copy appropriate conf.d files from config-map to emptyDir. if [[ $ordinal -eq 0 ]]; then #如果是master、则cpmaster配置文件 cp /mnt/config-map/master.cnf /mnt/conf.d/ else #否则cp slave配置文件 cp /mnt/config-map/slave.cnf /mnt/conf.d/ fi volumeMounts: - name: conf #临时卷、emptyDir mountPath: /mnt/conf.d - name: config-map mountPath: /mnt/config-map - name: clone-mysql #初始化容器2、用于生成mysql配置文件、并从上一个pod完成首次的全量数据clone(slave 3从slave2 clone，而不是每个slave都从master clone实现首次全量同步,但是后期都是与master实现增量同步) image: harbor.ik8s.cc/magedu/xtrabackup:1.0 command: - bash - "-c" - | set -ex # Skip the clone if data already exists. [[ -d /var/lib/mysql/mysql ]] && exit 0 # Skip the clone on master (ordinal index 0). [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} [[ $ordinal -eq 0 ]] && exit 0 #如果最后一位是0(master)则退出clone过程 # Clone data from previous peer. ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql #从上一个pod执行clone(binlog),xbstream为解压缩命令 # Prepare the backup.xue xtrabackup --prepare --target-dir=/var/lib/mysql #通过xtrabackup恢复binlog volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d containers: - name: mysql #业务容器1(mysql主容器) image: harbor.ik8s.cc/magedu/mysql:5.7.36 env: - name: MYSQL_ALLOW_EMPTY_PASSWORD value: "1" ports: - name: mysql containerPort: 3306 volumeMounts: - name: data #挂载数据目录至/var/lib/mysql mountPath: /var/lib/mysql subPath: mysql - name: conf #配置文件/etc/mysql/conf.d mountPath: /etc/mysql/conf.d resources: #资源限制 requests: cpu: 500m memory: 1Gi livenessProbe: #存活探针 exec: command: ["mysqladmin", "ping"] initialDelaySeconds: 30 periodSeconds: 10 timeoutSeconds: 5 readinessProbe: #就绪探针 exec: # Check we can execute queries over TCP (skip-networking is off). command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"] initialDelaySeconds: 5 periodSeconds: 2 timeoutSeconds: 1 - name: xtrabackup #业务容器2(xtrabackup),用于后期同步master 的binglog并恢复数据 image: harbor.ik8s.cc/magedu/xtrabackup:1.0 ports: - name: xtrabackup containerPort: 3307 command: - bash - "-c" - | set -ex cd /var/lib/mysql # Determine binlog position of cloned data, if any. if [[ -f xtrabackup_slave_info ]]; then # XtraBackup already generated a partial "CHANGE MASTER TO" query # because we're cloning from an existing slave. mv xtrabackup_slave_info change_master_to.sql.in # Ignore xtrabackup_binlog_info in this case (it's useless). rm -f xtrabackup_binlog_info elif [[ -f xtrabackup_binlog_info ]]; then # We're cloning directly from master. Parse binlog position. [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1 rm xtrabackup_binlog_info echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}', MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in #生成CHANGE MASTER命令 fi # Check if we need to complete a clone by starting replication. if [[ -f change_master_to.sql.in ]]; then echo "Waiting for mysqld to be ready (accepting connections)" until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done echo "Initializing replication from clone position" # In case of container restart, attempt this at-most-once. mv change_master_to.sql.in change_master_to.sql.orig #执行CHANGE MASTER操作并启动SLAVE mysql -h 127.0.0.1 <<EOF $(<change_master_to.sql.orig), MASTER_HOST='mysql-0.mysql', MASTER_USER='root', MASTER_PASSWORD='', MASTER_CONNECT_RETRY=10; START SLAVE; EOF fi # Start a server to send backups when requested by peers. #监听在3307端口，用于为下一个pod同步全量数据 exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c "xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root" volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d resources: requests: cpu: 100m memory: 100Mi volumes: - name: conf emptyDir: {} - name: config-map configMap: name: mysql volumeClaimTemplates: - metadata: name: data spec: accessModes: ["ReadWriteOnce"] resources: requests: storage: 10Gi 上述配置清单主要定义两个mysqlPod，其中每个pod中运行4个容器，第一个容器init容器主要目的是通过sts控制器创建pod的名称id来确定挂载master和slave配置；第二个初始化容器主要目的是用于克隆上一个pod的数据，即salve1从master上克隆数据，slave2从slave1克隆数据，以此类推；第三个就是mysql主容器，运行mysql实例；第四个容器主要用于给mysql主容器同步后期的增量数据的；
MYSQL SERVICE配置清单
# Headless service for stable DNS entries of StatefulSet members. apiVersion: v1 kind: Service metadata: namespace: magedu name: mysql labels: app: mysql spec: ports: - name: mysql port: 3306 clusterIP: None selector: app: mysql --- # Client service for connecting to any MySQL instance for reads. # For writes, you must instead connect to the master: mysql-0.mysql. apiVersion: v1 kind: Service metadata: name: mysql-read namespace: magedu labels: app: mysql spec: ports: - name: mysql port: 3306 selector: app: mysql 上述配置清单主要创建了两个service，第一个是一个无头service 用户返回后端所有pod端点；第二个service是一个默认clusterip类型service，这两个service都是可以的；
3.3.1、创建mysql pod
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl apply -f mysql-configmap.yaml -f mysql-services.yaml -f mysql-statefulset.yaml configmap/mysql created service/mysql created service/mysql-read created statefulset.apps/mysql created root@k8s-master01:~/k8s-data/yaml/magedu/mysql# 3.3.2、验证MySQL Pod状态
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl get pods -n magedu NAME READY STATUS RESTARTS AGE magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (113m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (114m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (114m ago) 11d mysql-0 2/2 Running 0 47s mysql-1 2/2 Running 0 23s redis-0 1/1 Running 2 (114m ago) 8d redis-1 1/1 Running 2 (114m ago) 8d redis-2 1/1 Running 2 (114m ago) 8d redis-3 1/1 Running 2 (114m ago) 8d redis-4 1/1 Running 2 (114m ago) 8d redis-5 1/1 Running 2 (114m ago) 8d ubuntu1804 0/1 Completed 0 8d zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (114m ago) 10d zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (114m ago) 10d zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (114m ago) 10d root@k8s-master01:~/k8s-data/yaml/magedu/mysql# 修改配置清单pod副本为3，看看对应pod是否能够正常running?
应用配置清单
3.3.3、验证MySQL主从同步是否正常
验证master状态
root@k8s-master01:~# kubectl exec -it mysql-0 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-0:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 691 Server version: 5.7.36-log MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show master statusG *************************** 1. row *************************** File: mysql-0-bin.000003 Position: 313 Binlog_Do_DB: Binlog_Ignore_DB: Executed_Gtid_Set: 1 row in set (0.01 sec) mysql> exit Bye root@mysql-0:/# exit exit root@k8s-master01:~# 验证slave状态
root@k8s-master01:~# kubectl exec -it mysql-1 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-1:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 708 Server version: 5.7.36 MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: mysql-0.mysql Master_User: root Master_Port: 3306 Connect_Retry: 10 Master_Log_File: mysql-0-bin.000003 Read_Master_Log_Pos: 313 Relay_Log_File: mysql-1-relay-bin.000002 Relay_Log_Pos: 481 Relay_Master_Log_File: mysql-0-bin.000003 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 313 Relay_Log_Space: 690 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 100 Master_UUID: 72724f41-0b65-11ee-b561-16065cd6961a Master_Info_File: /var/lib/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec) mysql> exit Bye root@mysql-1:/# exit exit root@k8s-master01:~# kubectl exec -it mysql-2 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-2:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 632 Server version: 5.7.36 MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: mysql-0.mysql Master_User: root Master_Port: 3306 Connect_Retry: 10 Master_Log_File: mysql-0-bin.000003 Read_Master_Log_Pos: 313 Relay_Log_File: mysql-2-relay-bin.000002 Relay_Log_Pos: 481 Relay_Master_Log_File: mysql-0-bin.000003 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 313 Relay_Log_Space: 690 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 100 Master_UUID: 72724f41-0b65-11ee-b561-16065cd6961a Master_Info_File: /var/lib/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec) mysql> exit Bye root@mysql-2:/# exit exit root@k8s-master01:~# 能够在slave上看到IO和SQL线程正常running，说明slave状态没有问题；
进入mysql-0创建数据库
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-0 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-0:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 355 Server version: 5.7.36-log MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | mysql | | performance_schema | | sys | | xtrabackup_backupfiles | +------------------------+ 5 rows in set (0.02 sec) mysql> create database mydb; Query OK, 1 row affected (0.00 sec) mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | mydb | | mysql | | performance_schema | | sys | | xtrabackup_backupfiles | +------------------------+ 6 rows in set (0.00 sec) mysql> 在slave pod中验证数据是否同步？
root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-1 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-1:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 437 Server version: 5.7.36 MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | mydb | | mysql | | performance_schema | | sys | | xtrabackup_backupfiles | +------------------------+ 6 rows in set (0.01 sec) mysql> exit Bye root@mysql-1:/# exit exit root@k8s-master01:~/k8s-data/yaml/magedu/mysql# kubectl exec -it mysql-2 -n magedu bash kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. Defaulted container "mysql" out of: mysql, xtrabackup, init-mysql (init), clone-mysql (init) root@mysql-2:/# mysql Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 361 Server version: 5.7.36 MySQL Community Server (GPL) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | mydb | | mysql | | performance_schema | | sys | | xtrabackup_backupfiles | +------------------------+ 6 rows in set (0.02 sec) mysql> exit Bye root@mysql-2:/# exit exit root@k8s-master01:~/k8s-data/yaml/magedu/mysql# 能够通过上述在主库创建数据库，从库能够正常同步，则说明mysql主从同步没有问题；
3.3.4、mysql⾼可⽤测试
3.3.4.1、删除master pod验证mysql高可用性
进入master，验证master数据是否丢失？
能够看到master数据并未丢失，这是因为该数据存放至远端nfs存储之上；
3.3.4.2、删除slave pod验证mysql高可用性
root@k8s-master01:~# kubectl get pods -n magedu NAME READY STATUS RESTARTS AGE magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (143m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (143m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (143m ago) 11d mysql-0 2/2 Running 0 3m6s mysql-1 2/2 Running 0 29m mysql-2 2/2 Running 0 27m redis-0 1/1 Running 2 (143m ago) 8d redis-1 1/1 Running 2 (143m ago) 8d redis-2 1/1 Running 2 (143m ago) 8d redis-3 1/1 Running 2 (143m ago) 8d redis-4 1/1 Running 2 (143m ago) 8d redis-5 1/1 Running 2 (143m ago) 8d ubuntu1804 0/1 Completed 0 8d zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (143m ago) 10d zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (143m ago) 10d zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (143m ago) 10d root@k8s-master01:~# kubectl delete pods mysql-1 -n magedu pod "mysql-1" deleted root@k8s-master01:~# kubectl get pods -n magedu NAME READY STATUS RESTARTS AGE magedu-nginx-deployment-5589bbf4bc-6gd2w 1/1 Running 8 (144m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-c7rtb 1/1 Running 4 (145m ago) 11d magedu-tomcat-app1-deployment-7754c8549c-prglk 1/1 Running 4 (145m ago) 11d mysql-0 2/2 Running 0 4m55s mysql-1 2/2 Running 0 55s mysql-2 2/2 Running 0 28m redis-0 1/1 Running 2 (145m ago) 8d redis-1 1/1 Running 2 (145m ago) 8d redis-2 1/1 Running 2 (145m ago) 8d redis-3 1/1 Running 2 (145m ago) 8d redis-4 1/1 Running 2 (145m ago) 8d redis-5 1/1 Running 2 (145m ago) 8d ubuntu1804 0/1 Completed 0 8d zookeeper1-675c5477cb-vmwwq 1/1 Running 4 (145m ago) 10d zookeeper2-759fb6c6f-7jktr 1/1 Running 4 (145m ago) 10d zookeeper3-5c78bb5974-vxpbh 1/1 Running 4 (145m ago) 10d root@k8s-master01:~# 进入slave验证数据
