Mysql通过binlog同步redis

实现过程

通过canal解析binlog，canal主要模拟了mysql的Slave向Master发送请求，当mysql有增删改查时则会出发请求将数据发送到canal服务中，canal将数据存放到内存，直到客户端程序(canal服务端和客户端程序都是由java编写,且客户端逻辑由我们借助com.alibaba.otter.canal工具包下的类完成开发)通过发布-订阅这种模式消费canal服务中的数据。

配置mysql

1.在my.ini文件里的【mysqld】下添加如下：

image

重启mysql，注意如果是文件名是my-default.ini要改名成my.ini

2.创建mysql用户，并配置canal权限，进入到mysql程序中，输入下列命令，创建用户，(用户名和密码都是：canal)：

CREATE USER canal IDENTIFIED BY 'canal';    

GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON数据库名.表名 TO 'canal'@'%';  

 -- GRANT ALL PRIVILEGES ON数据库名.表名 TO 'canal'@'%' ;  

 FLUSH PRIVILEGES;

下载并配置启动canal：

1.]官网地址：[https://github.com/alibaba/canal/releases，下载后解压

2.配置canal：主要配置的文件有两处，canal/conf/example/instance.properties和 canal/conf/canal.properties .下面对这两处做修改：

cd canal/conf/example/目录下对 instance.properties进行修改：

image

cd canal/conf/目录下对 canal.properties 进行修改：

image

3.启动canal：双击/bin/startup.bat文件启动

Java连接canal执行同步操作:

1.在maven项目中中加载canal和redis依赖包:

        
            com.alibaba.otter
            canal.client
            1.0.12
        
        
            redis.clients
            jedis
            2.4.2
        

2.建立canal客户端，从canal中获取数据，并将数据更新至Redis:

package canal;

import java.net.InetSocketAddress;
import java.util.List;

import com.alibaba.fastjson.JSONObject;
import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.protocol.Message;
import com.alibaba.otter.canal.protocol.CanalEntry.Column;
import com.alibaba.otter.canal.protocol.CanalEntry.Entry;
import com.alibaba.otter.canal.protocol.CanalEntry.EntryType;
import com.alibaba.otter.canal.protocol.CanalEntry.EventType;
import com.alibaba.otter.canal.protocol.CanalEntry.RowChange;
import com.alibaba.otter.canal.protocol.CanalEntry.RowData;
import com.alibaba.otter.canal.client.*;

/**
 * @Author: daijunchen
 * @Date: 2019/3/12 17:30
 */
public class ClientSample {

    public static void main(String args[]) {

        // 创建链接，hostname位canal服务器ip port位canal服务器端口，username，password可不填
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("127.0.0.1",
                11111), "example", "", "");
        int batchSize = 1000;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            while (true) {
                Message message = connector.getWithoutAck(batchSize); // 获取指定数量的数据
                long batchId = message.getId();
                int size = message.getEntries().size();
                if (batchId == -1 || size == 0) {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                } else {
                    printEntry(message.getEntries());
                }

                connector.ack(batchId); // 提交确认
                // connector.rollback(batchId); // 处理失败, 回滚数据
            }

        } finally {
            connector.disconnect();
        }
    }

    private static void printEntry(List entrys) {
        for (Entry entry : entrys) {
            if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {
                continue;
            }

            RowChange rowChage = null;
            try {
                rowChage = RowChange.parseFrom(entry.getStoreValue());
            } catch (Exception e) {
                throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),
                        e);
            }

            EventType eventType = rowChage.getEventType();
            System.out.println(String.format("================> binlog[%s:%s] , name[%s,%s] , eventType : %s",
                    entry.getHeader().getLogfileName(), entry.getHeader().getLogfileOffset(),
                    entry.getHeader().getSchemaName(), entry.getHeader().getTableName(),
                    eventType));

            for (RowData rowData : rowChage.getRowDatasList()) {
                if (eventType == EventType.DELETE) {
                    redisDelete(rowData.getBeforeColumnsList());
                } else if (eventType == EventType.INSERT) {
                    redisInsert(rowData.getAfterColumnsList());
                } else {
                    System.out.println("-------> before");
                    printColumn(rowData.getBeforeColumnsList());
                    System.out.println("-------> after");
                    redisUpdate(rowData.getAfterColumnsList());
                    printColumn(rowData.getAfterColumnsList());
                }
            }
        }
    }

    /**
     * 打印变化的数据
     *
     * @param columns
     */
    private static void printColumn(List columns) {
        for (Column column : columns) {
            System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());
        }
    }

    /**
     * 数据插入同步redis
     *
     * @param columns
     */
    private static void redisInsert(List columns) {
        JSONObject json = new JSONObject();
        for (Column column : columns) {
            json.put(column.getName(), column.getValue());
        }
        if (columns.size() > 0) {
            RedisUtil.stringSet("user:" + columns.get(0).getValue(), json.toJSONString());
        }
    }

    /**
     * 更新同步redis
     *
     * @param columns
     */
    private static void redisUpdate(List columns) {
        JSONObject json = new JSONObject();
        for (Column column : columns) {
            json.put(column.getName(), column.getValue());
        }
        if (columns.size() > 0) {
            RedisUtil.stringSet("user:" + columns.get(0).getValue(), json.toJSONString());
        }
    }

    /**
     * 数据删除同步redis
     *
     * @param columns
     */
    private static void redisDelete(List columns) {
        JSONObject json = new JSONObject();
        for (Column column : columns) {
            json.put(column.getName(), column.getValue());
        }
        if (columns.size() > 0) {
            RedisUtil.delKey("user:" + columns.get(0).getValue());
        }
    }

}

3.RedisUtil工具类，用来连接redis：

package canal;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

/**
 * @Author: daijunchen
 * @Date: 2019/3/12 17:29
 */
public class RedisUtil {

    // Redis服务器IP
    private static String ADDR = "127.0.0.1";

    // Redis的端口号
    private static int PORT = 6379;

    // 访问密码
    private static String AUTH = "";

    // 可用连接实例的最大数目，默认值为8；
    // 如果赋值为-1，则表示不限制；如果pool已经分配了maxActive个jedis实例，则此时pool的状态为exhausted(耗尽)。
    private static int MAX_ACTIVE = 1024;

    // 控制一个pool最多有多少个状态为idle(空闲的)的jedis实例，默认值也是8。
    private static int MAX_IDLE = 200;

    // 等待可用连接的最大时间，单位毫秒，默认值为-1，表示永不超时。如果超过等待时间，则直接抛出JedisConnectionException；
    private static int MAX_WAIT = 10000;

    // 过期时间
    protected static int expireTime = 660 * 660 * 24;

    // 连接池
    protected static JedisPool pool;

    /**
     * 静态代码，只在初次调用一次
     */
    static {
        JedisPoolConfig config = new JedisPoolConfig();
        //最大连接数
        config.setMaxTotal(MAX_ACTIVE);
        //最多空闲实例
        config.setMaxIdle(MAX_IDLE);
        //超时时间
        config.setMaxWaitMillis(MAX_WAIT);
        //
        config.setTestOnBorrow(false);
        pool = new JedisPool(config, ADDR, PORT, 1000);
    }

    /**
     * 获取jedis实例
     */
    protected static synchronized Jedis getJedis() {
        Jedis jedis = null;
        try {
            jedis = pool.getResource();
        } catch (Exception e) {
            e.printStackTrace();
            if (jedis != null) {
                pool.returnBrokenResource(jedis);
            }
        }
        return jedis;
    }

    /**
     * 释放jedis资源
     *
     * @param jedis
     * @param isBroken
     */
    protected static void closeResource(Jedis jedis, boolean isBroken) {
        try {
            if (isBroken) {
                pool.returnBrokenResource(jedis);
            } else {
                pool.returnResource(jedis);
            }
        } catch (Exception e) {

        }
    }

    /**
     * 是否存在key
     *
     * @param key
     */
    public static boolean existKey(String key) {
        Jedis jedis = null;
        boolean isBroken = false;
        try {
            jedis = getJedis();
            jedis.select(0);
            return jedis.exists(key);
        } catch (Exception e) {
            isBroken = true;
        } finally {
            closeResource(jedis, isBroken);
        }
        return false;
    }

    /**
     * 删除key
     *
     * @param key
     */
    public static void delKey(String key) {
        Jedis jedis = null;
        boolean isBroken = false;
        try {
            jedis = getJedis();
            jedis.select(0);
            jedis.del(key);
        } catch (Exception e) {
            isBroken = true;
        } finally {
            closeResource(jedis, isBroken);
        }
    }

    /**
     * 取得key的值
     *
     * @param key
     */
    public static String stringGet(String key) {
        Jedis jedis = null;
        boolean isBroken = false;
        String lastVal = null;
        try {
            jedis = getJedis();
            jedis.select(0);
            lastVal = jedis.get(key);
            jedis.expire(key, expireTime);
        } catch (Exception e) {
            isBroken = true;
        } finally {
            closeResource(jedis, isBroken);
        }
        return lastVal;
    }

    /**
     * 添加string数据
     *
     * @param key
     * @param value
     */
    public static String stringSet(String key, String value) {
        Jedis jedis = null;
        boolean isBroken = false;
        String lastVal = null;
        try {
            jedis = getJedis();
            jedis.select(0);
            lastVal = jedis.set(key, value);
            jedis.expire(key, expireTime);
        } catch (Exception e) {
            e.printStackTrace();
            isBroken = true;
        } finally {
            closeResource(jedis, isBroken);
        }
        return lastVal;
    }

    /**
     * 添加hash数据
     *
     * @param key
     * @param field
     * @param value
     */
    public static void hashSet(String key, String field, String value) {
        boolean isBroken = false;
        Jedis jedis = null;
        try {
            jedis = getJedis();
            if (jedis != null) {
                jedis.select(0);
                jedis.hset(key, field, value);
                jedis.expire(key, expireTime);
            }
        } catch (Exception e) {
            isBroken = true;
        } finally {
            closeResource(jedis, isBroken);
        }
    }
}

验证修改mysql数据库内容后发现redis也实时更新了：

image