InnoDB Cluster集群Mysql Router代理层最佳实践

InnoDB Cluster 集群 & Mysql-Router 代理层

前言

Mysql是现今最常用的关系型数据库之一，高可用一直是我们对软件服务的要求。常见的Mysql高可用是主从配置，在主节点挂掉后需要依赖监控脚本进行主从切换将从节点升级，后台服务代码层面也需要进行相关配置。那有没有更简约的办法做到后台代码零侵入呢，答案是有的，本文就采用 Mysql 官方的集群模式加官方的 Router 代理层实现 Mysql 对后台服务的隐藏，后台服务只需要像连接普通 Mysql 服务一样连接到 Router 即可。

这种方案优势非常明显：

1. MySQL Router 是官方出品，是轻量级代理程序，后台应用不可见。
2. Router 可自己实现读写分离。
3. 数据库服务器故障，业务可以正常运行。由MySQL Router来进行自动下线不可用服务器和替换主节点。
   
   现在直接把全套最佳实践正文发布如下（Docker版本三节点）。

1、InnoDB Cluster集群

1.1、Mysql8.0 standalone(建议至少3个节点才能保证高可用)

使用Mysql8.0镜像启动3个节点（一主两从），除server_id和report_host外其他配置均一致。

# docker-compose
services:
  mysql-server:
    # container_name: mysql-server
    image: mysql/mysql-server:8.0
    restart: always
    # volumes:
    # - /data/mysql-server:/var/lib/mysql
    network_mode: host
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_ROOT_HOST: '%'
    command: ["mysqld",
    "--server_id=1",
    "--report_host=$HOSTNAME", # 通信的ip地址
    "--report_port=3306", # 通信的端口
    "--binlog_checksum=NONE",
    "--gtid_mode=ON",
    "--enforce_gtid_consistency=ON",
    "--log_bin",
    "--log_slave_updates=ON",
    "--master_info_repository=TABLE",
    "--relay_log_info_repository=TABLE",
    "--transaction_write_set_extraction=XXHASH64",
    "--user=mysql",
    "--skip-host-cache",
    "--skip-name-resolve",
    "--default_authentication_plugin=mysql_native_password",
    "--binlog_transaction_dependency_tracking=WRITESET"]

1.2、使用mysql-shell建立集群

# 手动方式
mysqlsh --uri "root@mysql-server-1"

// init.js
var password = "root"
var clusterName = "mysqlCluster"

try {
  print('Setting up InnoDB cluster...\n');
  shell.connect('[email protected]:3306', password)
  var cluster = dba.createCluster(clusterName);
  print('Adding instances to the cluster.');
  cluster.addInstance({user: "root", host: "127.0.0.1", port: 3307, password: password}, {recoveryMethod:'clone'})
  print('.');
  cluster.addInstance({user: "root", host: "127.0.0.1", port: 3308, password: password}, {recoveryMethod:'clone'})
  print('.\nInstances successfully added to the cluster.');
  print('\nInnoDB cluster deployed successfully.\n');
} catch(e) {
  print('\nThe InnoDB cluster could not be created.\n\nError: ' + e.message + '\n');
}

1.3、使用docker自动建立集群

1.3.1、docker-entrypoint.sh

#!/bin/bash
set -e

if [ -n "$1" ]; then
  exec "$@"
fi

if [ -z "$MYSQL_HOST" ]; then
  echo "-e MYSQL_HOST is required."
  exit 1
fi
if [ -z "$MYSQL_PORT" ]; then
  echo "-e MYSQL_PORT is required."
  exit 1
fi
if [ -z "$MYSQL_USER" ]; then
  echo "-e MYSQL_USER is required."
  exit 1
fi
if [ -z "$MYSQL_PASSWORD" ]; then
  echo "-e MYSQL_PASSWORD is required."
  exit 1
fi

max_tries=10
attempt_num=0
until (echo > "/dev/tcp/$MYSQL_HOST/$MYSQL_PORT") >/dev/null 2>&1; do
  echo "Waiting for mysql server $MYSQL_HOST ($attempt_num/$max_tries)"
  sleep $(( attempt_num++ ))
  if [ attempt_num -eq max_tries ]; then
    exit 1
  fi
done

if [ -n "$MYSQLSH_SCRIPT" ]; then
  mysqlsh "$MYSQL_USER@$MYSQL_HOST:$MYSQL_PORT" --password="$MYSQL_PASSWORD" -f "$MYSQLSH_SCRIPT" || true
fi
if [ -n "$MYSQL_SCRIPT" ]; then
  mysqlsh "$MYSQL_USER@$MYSQL_HOST:$MYSQL_PORT" --password="$MYSQL_PASSWORD" --sql -f "$MYSQL_SCRIPT" || true
fi

1.3.2、Dockerfile

FROM alpine:3.18 as download

ARG pkg='mysql-shell-8.0.33-linux-glibc2.12-x86-64bit'
RUN wget "https://dev.mysql.com/get/Downloads/MySQL-Shell/$pkg.tar.gz"

###
FROM debian:bullseye-slim

ARG pkg='mysql-shell-8.0.33-linux-glibc2.12-x86-64bit'
COPY --from=download "/$pkg.tar.gz" /opt
COPY docker-entrypoint.sh /bin/
RUN cd /opt && \
    tar -xzf "$pkg.tar.gz" && \
    ln -s "/opt/$pkg/bin/mysqlsh" /bin/ && \
    rm -f "/$pkg.tar.gz" && \
    chmod 755 /bin/docker-entrypoint.sh
ENTRYPOINT ["docker-entrypoint.sh"]
CMD []

1.3.3、docker-compose

services:
  mysql-shell:
    container_name: mysql-shell
    image: mysql-shell:8.0
    build: ./mysql-shell-builder
    restart: on-failure
    volumes:
    - ./scripts/:/scripts/
    environment:
    - MYSQL_HOST=mysql-server-1
    - MYSQL_PORT=3306
    - MYSQL_USER=root
    - MYSQL_PASSWORD=root
    - MYSQLSH_SCRIPT=/scripts/init.js
    - MYSQL_SCRIPT=/scripts/init.sql
    depends_on:
    - mysql-server-1
    - mysql-server-2
    - mysql-server-3

2、Mysql Router代理层

# docker-compose
services:
  mysql-router:
    container_name: mysql-router
    image: mysql/mysql-router:8.0
    restart: always
    ports:
    - 3306:6446
    environment:
    - MYSQL_HOST=mysql-server-1
    - MYSQL_PORT=3306
    - MYSQL_USER=root
    - MYSQL_PASSWORD=root
    - MYSQL_INNODB_NUM_MEMBERS=3 #Wait for this number of cluster instances to be online.
    - MYSQL_CREATE_ROUTER_USER=0
    depends_on:
    - mysql-server-1
    - mysql-server-2
    - mysql-server-3
    - mysql-shell

3、整合

3.1、目录结构

- <PROJECT_DIRECTORY>
  - mysql-shell-builder
    * docker-entrypoint.sh    * Dockerfile
  - scripts
    * init.js
    * init.sql [optional]
  * docker-compose.yaml

3.2、docker-compose.yaml

version: '3'

services:
  mysql-server-1:
    container_name: mysql-server-1
    image: mysql/mysql-server:8.0
    restart: always
    volumes:
    - /data/mysql-server-1:/var/lib/mysql
    # ports:
    # - 3301:3306
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_ROOT_HOST: '%'
    command: ["mysqld","--server_id=1","--binlog_checksum=NONE","--gtid_mode=ON","--enforce_gtid_consistency=ON","--log_bin","--log_slave_updates=ON","--master_info_repository=TABLE","--relay_log_info_repository=TABLE","--transaction_write_set_extraction=XXHASH64","--user=mysql","--skip-host-cache","--skip-name-resolve","--default_authentication_plugin=mysql_native_password","--binlog_transaction_dependency_tracking=WRITESET"]

  mysql-server-2:
    container_name: mysql-server-2
    image: mysql/mysql-server:8.0
    restart: always
    volumes:
    - /data/mysql-server-2:/var/lib/mysql
    # ports:
    # - 3302:3306
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_ROOT_HOST: '%'
    command: ["mysqld","--server_id=2","--binlog_checksum=NONE","--gtid_mode=ON","--enforce_gtid_consistency=ON","--log_bin","--log_slave_updates=ON","--master_info_repository=TABLE","--relay_log_info_repository=TABLE","--transaction_write_set_extraction=XXHASH64","--user=mysql","--skip-host-cache","--skip-name-resolve","--default_authentication_plugin=mysql_native_password","--binlog_transaction_dependency_tracking=WRITESET"]

  mysql-server-3:
    container_name: mysql-server-3
    image: mysql/mysql-server:8.0
    restart: always
    volumes:
    - /data/mysql-server-3:/var/lib/mysql
    # ports:
    # - 3303:3306
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_ROOT_HOST: '%'
    command: ["mysqld","--server_id=3","--binlog_checksum=NONE","--gtid_mode=ON","--enforce_gtid_consistency=ON","--log_bin","--log_slave_updates=ON","--master_info_repository=TABLE","--relay_log_info_repository=TABLE","--transaction_write_set_extraction=XXHASH64","--user=mysql","--skip-host-cache","--skip-name-resolve","--default_authentication_plugin=mysql_native_password","--binlog_transaction_dependency_tracking=WRITESET"]

  mysql-shell:
    container_name: mysql-shell
    image: mysql-shell:8.0
    build: ./mysql-shell-builder
    restart: on-failure
    volumes:
    - ./scripts/:/scripts/
    environment:
    - MYSQL_HOST=mysql-server-1
    - MYSQL_PORT=3306
    - MYSQL_USER=root
    - MYSQL_PASSWORD=root
    - MYSQLSH_SCRIPT=/scripts/init.js
    # - MYSQL_SCRIPT=/scripts/init.sql
    depends_on:
    - mysql-server-1
    - mysql-server-2
    - mysql-server-3

  mysql-router:
    container_name: mysql-router
    image: mysql/mysql-router:8.0
    restart: always
    ports:
    - 3306:6446
    environment:
    - MYSQL_HOST=mysql-server-1
    - MYSQL_PORT=3306
    - MYSQL_USER=root
    - MYSQL_PASSWORD=root
    - MYSQL_INNODB_NUM_MEMBERS=3 #Wait for this number of cluster instances to be online.
    - MYSQL_CREATE_ROUTER_USER=0
    depends_on:
    - mysql-server-1
    - mysql-server-2
    - mysql-server-3
    - mysql-shell

后台启动

docker compose up -d

后记

官方平台，对服务透明，自动故障处理，想要的功能它都有。就是首次配置可能需要多花点时间，但是参考本文，相信你可以对这套实践有更快的理解，欢迎点赞收藏！