kubernetes的有状态服务statefulset实现MySQL主从复制案
client --> headless serivce name --> Pod-0,pod-1,
client --> serivce name --> clusterIP --> Pod-0,pod-1,
传统方式：MyCAT,proxy
K8s读写分离:statefulset,headless,coredns
写
mysql-0.mysql.default.svc.clsuter.local
读
mysql.default.svc.clsuter.local
mysql-read.default.svc.clsuter.local
mysql-0.mysql.default.svc.clsuter.local
mysql-1.mysql.default.svc.clsuter.local
mysql-2.mysql.default.svc.clsuter.local
案例：MySQL 主从复制集群
https://kubernetes.io/zh-cn/docs/tasks/run-application/run-replicated-statefulapplication/
准备 NFS 服务
配置动态置备的SC
准备基于NFS的 StorageClass
创建 NFS 服务
#NFS服务器软件安装
# 安装 nfs-utils（包含 nfs-server 服务）
dnf install -y nfs-utils
# 启动并设置开机自启
systemctl enable --now nfs-server
# 验证状态
systemctl status nfs-server
mkdir -p /data/sc-nfs/
#授权worker节点的网段可以挂载
[root@master1 ~]# cat /etc/exports #/data/nfsshare 192.168.3.0/24(rw,sync,no_root_squash) #/nfsdata *(rw,no_root_squash) /data/sc-nfs *(rw,no_root_squash)
[root@master1 ~]# exportfs -r [root@master1 ~]# exportfs -v /data/sc-nfs <world>(sync,wdelay,hide,no_subtree_check,sec=sys,rw,secure,no_root_squash,no_all_squash)
#并在所有worker节点安装NFS客户端
dnf install -y nfs-utils
#在所有节点节点添加nfs..org的域名解析指定NFS服务器的地址
[root@node1 ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.3.60 kubeapi.org kubeapi 192.168.3.60 master1.org master1 192.168.3.60 nfs.org master1 192.168.3.61 master2.org master2 192.168.3.62 master3.org master3 192.168.3.63 node1.org node1 192.168.3.64 node2.org node2 192.168.3.65 node3.org node3 192.168.3.66 ha1.org ha1 192.168.3.67 ha2.org ha2
创建 ServiceAccount 并授权
#建议创建独立的名称空间
kubectl create ns sc-nfs
[root@master1 sc-nfs]# cat rbac.yaml apiVersion: v1 kind: ServiceAccount metadata: name: nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs --- kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 metadata: name: nfs-client-provisioner-runner rules: - apiGroups: [""] resources: ["nodes"] verbs: ["get", "list", "watch"] - apiGroups: [""] resources: ["persistentvolumes"] verbs: ["get", "list", "watch", "create", "delete"] - apiGroups: [""] resources: ["persistentvolumeclaims"] verbs: ["get", "list", "watch", "update"] - apiGroups: ["storage.k8s.io"] resources: ["storageclasses"] verbs: ["get", "list", "watch"] - apiGroups: [""] resources: ["events"] verbs: ["create", "update", "patch"] --- kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: run-nfs-client-provisioner subjects: - kind: ServiceAccount name: nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs roleRef: kind: ClusterRole name: nfs-client-provisioner-runner apiGroup: rbac.authorization.k8s.io --- kind: Role apiVersion: rbac.authorization.k8s.io/v1 metadata: name: leader-locking-nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs rules: - apiGroups: [""] resources: ["endpoints"] verbs: ["get", "list", "watch", "create", "update", "patch"] --- kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: leader-locking-nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs subjects: - kind: ServiceAccount name: nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs roleRef: kind: Role name: leader-locking-nfs-client-provisioner apiGroup: rbac.authorization.k8s.io
kubectl apply -f rbac.yaml
[root@master1 sc-nfs-1]# kubectl get sa -n sc-nfs NAME AGE default 3d8h nfs-client-provisioner 3d8h
部署 NFS-Subdir-External-Provisioner 对应的 Deployment
[root@master1 sc-nfs-1]# cat nfs-client-provisioner.yaml apiVersion: apps/v1 kind: Deployment metadata: name: nfs-client-provisioner labels: app: nfs-client-provisioner # replace with namespace where provisioner is deployed #namespace: default namespace: sc-nfs spec: replicas: 1 strategy: type: Recreate selector: matchLabels: app: nfs-client-provisioner template: metadata: labels: app: nfs-client-provisioner spec: serviceAccountName: nfs-client-provisioner containers: - name: nfs-client-provisioner image: registry.cn-beijing.aliyuncs.com/wangxiaochun/nfs-subdir-external-provisioner:v4.0.2 #image: wangxiaochun/nfs-subdir-external-provisioner:v4.0.2 #image: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2 imagePullPolicy: IfNotPresent volumeMounts: - name: nfs-client-root mountPath: /persistentvolumes env: - name: PROVISIONER_NAME value: k8s-sigs.io/nfs-subdir-external-provisioner #名称确保与 nfs-StorageClass.yaml文件中的provisioner名称保持一致 - name: NFS_SERVER value: nfs.org # NFS SERVER_IP - name: NFS_PATH value: /data/sc-nfs # NFS 共享目录 volumes: - name: nfs-client-root nfs: server: nfs.org # NFS SERVER_IP path: /data/sc-nfs # NFS 共享目录
通过第三方软件管理实现nfs动态置备功能
需要设置环境变量
通过第三方软件管理nfs服务器 /data/sc-nfs下的子目录 每个子目录自动创建对应pv
kubectl apply -f nfs-client-provisioner.yaml
[root@master1 sc-nfs]# kubectl get pod -n sc-nfs -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nfs-client-provisioner-d5dc647db-w8gxw 1/1 Running 0 28s 10.244.2.187 node2.org <none> <none>
#注意:如果失败,检查是否worker节点安装了nfs-client
创建 NFS 资源的 StorageClass
StorageClass 作用声明使用第三方置备软件管理pv
[root@master1 sc-nfs-1]# cat nfs-StorageClass.yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: sc-nfs annotations: storageclass.kubernetes.io/is-default-class: "true" # 是否设置为默认的storageclass provisioner: k8s-sigs.io/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME' parameters: archiveOnDelete: "true" # 设置为"false"时删除PVC不会保留数据,"true"则保留数据
#应用
kubectl apply -f nfs-StorageClass.yaml
#查看是否创建
[root@master1 sc-nfs-1]# kubectl get sc -n sc-nfs NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE sc-nfs (default) k8s-sigs.io/nfs-subdir-external-provisioner Delete Immediate false 3d8h
#提前准备名为sc-nfs的storage Class
创建 ConfigMap
#https://k8s.io/examples/application/mysql/mysql-configmap.yaml
#MySQL的配置
apiVersion: v1 kind: ConfigMap metadata: name: mysql labels: app: mysql app.kubernetes.io/name: mysql data: primary.cnf: | # Apply this config only on the primary. [mysqld] log-bin replica.cnf: | # Apply this config only on replicas. [mysqld] super-read-only
kubectl apply -f statefulset-mysql-configmap.yaml
创建 Service
# https://k8s.io/examples/application/mysql/mysql-services.yaml
# 为 StatefulSet 成员提供稳定的 DNS 表项的无头服务（Headless Service）
# 主节点的对应的Service
# 用于连接到任一 MySQL 实例执行读操作的客户端服务
# 对于写操作，必须连接到主服务器：mysql-0.mysql
# 从节点的对应的Service，注意：此处无需无头服务（Headless Service）
# 下面的service可以不创建，直接使用无头服务mysql也可以
[root@master1 sc-nfs-mysql]# cat statefulset-mysql-svc.yaml # Headless service for stable DNS entries of StatefulSet members. apiVersion: v1 kind: Service metadata: name: mysql labels: app: mysql app.kubernetes.io/name: 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 primary: mysql-0.mysql. apiVersion: v1 kind: Service metadata: name: mysql-read labels: app: mysql app.kubernetes.io/name: mysql readonly: "true" spec: ports: - name: mysql port: 3306 selector: app: mysql
kubectl apply -f statefulset-mysql-svc.yaml
[root@master1 sc-nfs-mysql]# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18d mysql ClusterIP None <none> 3306/TCP 14s mysql-read ClusterIP 10.102.236.133 <none> 3306/TCP 14s
创建 statefulset
[root@master1 sc-nfs-mysql]# cat statefulset-mysql-statefulset.yaml --- apiVersion: apps/v1 kind: StatefulSet metadata: name: mysql spec: selector: matchLabels: app: mysql app.kubernetes.io/name: mysql serviceName: mysql replicas: 3 template: metadata: labels: app: mysql app.kubernetes.io/name: mysql spec: initContainers: - name: init-mysql #image: mysql:5.7 image: registry.cn-beijing.aliyuncs.com/wangxiaochun/mysql:5.7 command: - bash - "-c" - | set -ex # 基于 Pod 序号生成 MySQL 服务器的 ID。 [[ $HOSTNAME =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} #BASH_REMATCH是bash内置数组变量，存放从前面的=~正则表达式匹配的分组的结果，BASH_REMATCH[1]存放第1个分组 echo [mysqld] > /mnt/conf.d/server-id.cnf # 添加偏移量以避免使用 server-id=0 这一保留值。 echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf # 将合适的 conf.d 文件从 config-map 复制到 emptyDir。 if [[ $ordinal -eq 0 ]]; then cp /mnt/config-map/primary.cnf /mnt/conf.d/ else cp /mnt/config-map/replica.cnf /mnt/conf.d/ fi volumeMounts: - name: conf mountPath: /mnt/conf.d - name: config-map mountPath: /mnt/config-map - name: clone-mysql #image: gcr.io/google-samples/xtrabackup:1.0 image: registry.cn-beijing.aliyuncs.com/wangxiaochun/xtrabackup:1.0 command: - bash - "-c" - | set -ex # 如果已有数据，则跳过克隆。 [[ -d /var/lib/mysql/mysql ]] && exit 0 # 跳过主实例（序号索引 0）的克隆。 [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} [[ $ordinal -eq 0 ]] && exit 0 # 从原来的对等节点克隆数据。 ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql # 准备备份。 xtrabackup --prepare --target-dir=/var/lib/mysql volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d containers: - name: mysql #image: mysql:5.7 image: registry.cn-beijing.aliyuncs.com/wangxiaochun/mysql:5.7 env: - name: MYSQL_ALLOW_EMPTY_PASSWORD value: "1" ports: - name: mysql containerPort: 3306 volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d resources: requests: cpu: 500m memory: 1Gi livenessProbe: exec: command: ["mysqladmin", "ping"] initialDelaySeconds: 30 periodSeconds: 10 timeoutSeconds: 5 readinessProbe: exec: # 检查我们是否可以通过 TCP 执行查询（skip-networking 是关闭的）。 command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"] initialDelaySeconds: 5 periodSeconds: 2 timeoutSeconds: 1 - name: xtrabackup #image: gcr.io/google-samples/xtrabackup:1.0 image: registry.cn-beijing.aliyuncs.com/wangxiaochun/xtrabackup:1.0 ports: - name: xtrabackup containerPort: 3307 command: - bash - "-c" - | set -ex cd /var/lib/mysql # 确定克隆数据的 binlog 位置（如果有的话）。 if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then # XtraBackup 已经生成了部分的 “CHANGE MASTER TO” 查询 # 因为从一个现有副本进行克隆。(需要删除末尾的分号!) cat xtrabackup_slave_info | sed -E 's/;$//g' > change_master_to.sql.in # 在这里要忽略 xtrabackup_binlog_info （它是没用的）。 rm -f xtrabackup_slave_info xtrabackup_binlog_info elif [[ -f xtrabackup_binlog_info ]]; then # 直接从主实例进行克隆。解析 binlog 位置。 [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1 rm -f xtrabackup_binlog_info xtrabackup_slave_info echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\ MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in fi # 检查是否需要通过启动复制来完成克隆。 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" mysql -h 127.0.0.1 \ -e "$(<change_master_to.sql.in), \ MASTER_HOST='mysql-0.mysql', \ MASTER_USER='root', \ MASTER_PASSWORD='', \ MASTER_CONNECT_RETRY=10; \ START SLAVE;" || exit 1 # 如果容器重新启动，最多尝试一次。 mv change_master_to.sql.in change_master_to.sql.orig fi # 当对等点请求时，启动服务器发送备份。 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"] storageClassName: "sc-nfs" #如果使用StorageClass,启用此行 resources: requests: storage: 10Gi
kubectl apply -f statefulset-mysql-statefulset.yaml
[root@master1 sc-nfs-mysql]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES mysql-0 2/2 Running 0 16m 10.244.2.40 node2.org <none> <none> mysql-1 2/2 Running 1 (14m ago) 15m 10.244.1.44 node1.org <none> <none> mysql-2 2/2 Running 1 (113s ago) 3m6s 10.244.3.68 node3.org <none> <none>
验证
#创建一个测试Pod
kubectl run mysql-client --rm --tty -i --restart='Never' \
--image registry.cn-beijing.aliyuncs.com/wangxiaochun/mysql:8.0.29-oracle \
--namespace default \
--command -- bash
进入主节点
[root@master1 ~]# kubectl run mysql-client --rm --tty -i --restart='Never' \ > --image registry.cn-beijing.aliyuncs.com/wangxiaochun/mysql:8.0.29-oracle \ > --namespace default \ > --command -- bash All commands and output from this session will be recorded in container logs, including credentials and sensitive information passed through the command prompt. If you don't see a command prompt, try pressing enter. bash-4.4# bash-4.4#
有两个dump线程
bash-4.4# mysql -uroot -hmysql-0.mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 811 Server version: 5.7.13-log MySQL Community Server (GPL) Copyright (c) 2000, 2022, 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 processlist; +-----+------+-------------------+------+-------------+------+---------------------------------------------------------------+------------------+ | Id | User | Host | db | Command | Time | State | Info | +-----+------+-------------------+------+-------------+------+---------------------------------------------------------------+------------------+ | 52 | root | 10.244.1.44:58298 | NULL | Binlog Dump | 1275 | Master has sent all binlog to slave; waiting for more updates | NULL | | 499 | root | 10.244.3.68:60176 | NULL | Binlog Dump | 530 | Master has sent all binlog to slave; waiting for more updates | NULL | | 811 | root | 10.244.1.45:55210 | NULL | Query | 0 | starting | show processlist | +-----+------+-------------------+------+-------------+------+---------------------------------------------------------------+------------------+ 3 rows in set (0.01 sec) mysql>
两个dump 从节点ip
[root@master1 sc-nfs-mysql]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES mysql-0 2/2 Running 0 24m 10.244.2.40 node2.org <none> <none> mysql-1 2/2 Running 1 (22m ago) 23m 10.244.1.44 node1.org <none> <none> mysql-2 2/2 Running 1 (9m37s ago) 10m 10.244.3.68 node3.org <none> <none> mysql-client 1/1 Running 0 2m59s 10.244.1.45 node1.org <none> <none>
mysql> show master logs; +--------------------+-----------+ | Log_name | File_size | +--------------------+-----------+ | mysql-0-bin.000001 | 99474 | | mysql-0-bin.000002 | 2995461 | | mysql-0-bin.000003 | 154 | +--------------------+-----------+ 3 rows in set (0.00 sec)
进入从节点
#验证主从关系
bash-4.4# mysql -uroot -hmysql-1.mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 897 Server version: 5.7.13 MySQL Community Server (GPL) Copyright (c) 2000, 2022, 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> mysql> show slave status\G; *************************** 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: 154 Relay_Log_File: mysql-1-relay-bin.000002 Relay_Log_Pos: 322 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: 154 Relay_Log_Space: 531 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: 24c39922-5a89-11f1-a274-4250b4c8694e 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) ERROR: No query specified
bash-4.4# mysql -uroot -hmysql-2.mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 495 Server version: 5.7.13 MySQL Community Server (GPL) Copyright (c) 2000, 2022, 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 status\G; *************************** 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: 154 Relay_Log_File: mysql-2-relay-bin.000002 Relay_Log_Pos: 322 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: 154 Relay_Log_Space: 531 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: 24c39922-5a89-11f1-a274-4250b4c8694e 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) ERROR: No query specified
进入主节点创建数据
bash-4.4# mysql -uroot -hmysql-0.mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1062 Server version: 5.7.13-log MySQL Community Server (GPL) Copyright (c) 2000, 2022, 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> mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | mysql | | performance_schema | | sys | | xtrabackup_backupfiles | +------------------------+ 5 rows in set (0.00 sec) mysql> mysql> create database db22; Query OK, 1 row affected (0.01 sec) mysql> use db22; Database changed mysql> create table students(id int,name char(10)); Query OK, 0 rows affected (0.02 sec) mysql> insert students values(1,'tom'); Query OK, 1 row affected (0.02 sec) mysql> insert students values(2,'jack'); Query OK, 1 row affected (0.00 sec)
主从同步
bash-4.4# mysql -uroot -hmysql-1.mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1120 Server version: 5.7.13 MySQL Community Server (GPL) Copyright (c) 2000, 2022, 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> mysql> select * from db22.students; +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ 2 rows in set (0.00 sec)
用无头服务service 读数据
bash-4.4# mysql -uroot -hmysql.default.svc.cluster.local -e 'select * from db22.students;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+
[root@master1 sc-nfs-mysql]# kubectl get ep mysql Warning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice NAME ENDPOINTS AGE mysql 10.244.1.44:3306,10.244.2.40:3306,10.244.3.68:3306 38m
用有头服务 mysql-read service 可以读
bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ bash-4.4#
读3个pod 轮询了 随机调度到后端的pod上
bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-2 | +------------+ bash-4.4# bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-0 | +------------+ bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-1 | +------------+ bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-2 | +------------+
无头服务 使用mysql service 会 会话粘上
bash-4.4# bash-4.4# bash-4.4# mysql -uroot -hmysql-read.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' bash: bash-4.4#: command not found bash-4.4# bash-4.4# bash-4.4# mysql -uroot -hmysql.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-1 | +------------+ bash-4.4# mysql -uroot -hmysql.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-1 | +------------+ bash-4.4# mysql -uroot -hmysql.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-1 | +------------+ bash-4.4# mysql -uroot -hmysql.default.svc.cluster.local -e 'select * from db22.students;select @@hostname;' +------+------+ | id | name | +------+------+ | 1 | tom | | 2 | jack | +------+------+ +------------+ | @@hostname | +------------+ | mysql-1 | +------------+
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