一 、 业务场景
使用mysql 数据存储，Redis 做缓存查询。
二、 架构如下
三、实施步骤
1.下载最新版本的https://github.com/alibaba/canal/releases/
2. 可以在linux 或者windows上执行都可以。 修改canal/conf/example/instance.properties
3.启动 canal
./canal/startup.sh
4.java 连接canal
4.1 配置pom.xml
redis.clientsjedis2.4.2
<dependency> <groupId>com.alibaba.otter</groupId> <artifactId>canal.client</artifactId> <version>1.0.24</version>
</dependency>
注意此处spring boot里面配置的时候会报错。需要处理一下。
4.2 编写canal客户的程序
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.common.utils.AddressUtils;
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.*;
public class CanalClient{
public static void main(String args[]) {
CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(AddressUtils.getHostIp(),
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<Entry> 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());
}
}
}
}
private static void printColumn( List<Column> columns) {
for (Column column : columns) {
System.out.println(column.getName() + " : " + column.getValue() + " update=" + column.getUpdated());
}
}
private static void redisInsert( List<Column> 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());
}
}
private static void redisUpdate( List<Column> 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());
}
}
private static void redisDelete( List<Column> 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());
}
}
}
//// redis 工具类
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class RedisUtil {
// Redis服务器IP
private static String ADDR = "0.0.0.0";
// Redis的端口号
private static int PORT = 6379;
// 访问密码
//private static String AUTH = "admin";
// 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 = 60 * 60 *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);
}
}
}
4.3 canal客户端启动....
4.4 编写数据库存储过程测试数据 。
4.4.1 写存储过程 test
DROP PROCEDURE test;
DELIMITER $$
CREATE PROCEDURE test(IN number INT)
BEGIN
DECLARE i INT(8) DEFAULT 0;
SET i=1;
WHILE i<=number DO
INSERT INTO student(NAME,age) VALUES('ceshi',i);
SET i=i+1;
END WHILE;
END$$
4.4.2 执行存储过程 call test(10000);
备注：
1.如果是同步的两个表情况下 ，相同的Id 将会覆盖 所以建议同步一个表
2.经过测试，3个列，存储过程连续insert 20000条记录 ,没有明显延迟。
3.存储过程insert 30000记录 ，执行时间11.826秒 ，缓存数据库有明显延迟。
4.spring boot 做微服务时，加入canal 包会报错。 按下面的写法排除：
<dependency>
<groupId>com.alibaba.otter</groupId>
<artifactId>canal.client</artifactId>
<version>1.0.24</version>
<exclusions>
<exclusion>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
</exclusion>
<exclusion>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
</exclusion>
<exclusion>
<groupId>org.springframework</groupId>
<artifactId>spring</artifactId>
</exclusion>
</exclusions>
</dependency>
5.测试中我使用了spring boot 启动成功后直接执行canal 客户端程序。需要做如下配置
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
/**
* Created by mark on 2017/9/21.
*/
@Component
public class ServiceListener implements ApplicationListener<ContextRefreshedEvent> {
@Autowired
private CanalClientI canalClientI;
@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
if(event.getApplicationContext().getParent() == null)//root application context 没有parent，他就是老大.
{
//需要执行的逻辑代码，当spring容器初始化完成后就会执行该方法。
System.out.println("\n\n\n\n\n______________\n\n\n加载了\n\n_________\n\n");
canalClientI.run();
}
}
}
