利用Canal完成Mysql資料同步Redis
流程
Canal的原理是模擬Slave向Master傳送請求,Canal解析binlog,但不將解析結果持久化,而是儲存在記憶體中,每次有客戶端讀取一次訊息,就刪除該訊息。這裡所說的客戶端,就需要我們寫一個連線Canal的程式,持續從Canal獲取資料。
步驟
一、配置Canal
參考https://github.com/alibaba/canal
【mysql配置】
1,配置引數
2,在mysql中 配置canal資料庫管理使用者,配置相應許可權(repication許可權)[mysqld] log-bin=mysql-bin #新增這一行就ok binlog-format=ROW #選擇row模式 server_id=1 #配置mysql replaction需要定義,不能和canal的slaveId重複
CREATE USER canal IDENTIFIED BY 'canal';
GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
-- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ;
FLUSH PRIVILEGES;
【canal下載和配置】
1,下載canal https://github.com/alibaba/canal/releases
2,解壓
mkdir /tmp/canal
tar zxvf canal.deployer-$version.tar.gz -C /tmp/canal
3,修改配置檔案vi conf/example/instance.properties
################################################# ## mysql serverId canal.instance.mysql.slaveId = 1234 # position info,需要改成自己的資料庫資訊 canal.instance.master.address = 127.0.0.1:3306 canal.instance.master.journal.name = canal.instance.master.position = canal.instance.master.timestamp = #canal.instance.standby.address = #canal.instance.standby.journal.name = #canal.instance.standby.position = #canal.instance.standby.timestamp = # username/password,需要改成自己的資料庫資訊 canal.instance.dbUsername = canal canal.instance.dbPassword = canal canal.instance.defaultDatabaseName = canal.instance.connectionCharset = UTF-8 # table regex canal.instance.filter.regex = .*\\..* #################################################
【canal啟動和關閉】
1,啟動
sh bin/startup.sh
2,檢視日誌vi logs/canal/canal.log
2013-02-05 22:45:27.967 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## start the canal server.
<pre name="user-content-code">2013-02-05 22:45:28.113 [main] INFO com.alibaba.otter.canal.deployer.CanalController - ## start the canal server[10.1.29.120:11111]
2013-02-05 22:45:28.210 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## the canal server is running now ......
具體instance的日誌:vi logs/example/example.log
2013-02-05 22:50:45.636 [main] INFO c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [canal.properties]
2013-02-05 22:50:45.641 [main] INFO c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [example/instance.properties]
2013-02-05 22:50:45.803 [main] INFO c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start CannalInstance for 1-example
2013-02-05 22:50:45.810 [main] INFO c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start successful....
3,關閉sh bin/stop.sh
注意:
1,這裡只需要配置好引數後,就可以直接執行
2,Canal沒有解析後的檔案,不會持久化
二、建立客戶端
參考https://github.com/alibaba/canal/wiki/ClientExample
其中一個是連線canal並操作的類,一個是redis的工具類,使用maven主要是依賴包的下載很方便。
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.alibaba.otter</groupId>
<artifactId>canal.sample</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>com.alibaba.otter</groupId>
<artifactId>canal.client</artifactId>
<version>1.0.12</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>3.1.2.RELEASE</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.4.2</version>
</dependency>
</dependencies>
<build/>
</project>
2,ClientSample程式碼
這裡主要做兩個工作,一個是迴圈從Canal上取資料,一個是將資料更新至Redis
package canal.sample;
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 ClientSample {
public static void main(String args[]) {
// 建立連結
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); // 獲取指定數量的資料
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); // 提交確認
// connector.rollback(batchId); // 處理失敗, 回滾資料
}
} 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());
}
}
}
3,RedisUtil程式碼
package canal.sample;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class RedisUtil {
// Redis伺服器IP
private static String ADDR = "10.1.2.190";
// Redis的埠號
private static int PORT = 6379;
// 訪問密碼
private static String AUTH = "admin";
// 可用連線例項的最大數目,預設值為8;
// 如果賦值為-1,則表示不限制;如果pool已經分配了maxActive個jedis例項,則此時pool的狀態為exhausted(耗盡)。
private static int MAX_ACTIVE = 1024;
// 控制一個pool最多有多少個狀態為idle(空閒的)的jedis例項,預設值也是8。
private static int MAX_IDLE = 200;
// 等待可用連線的最大時間,單位毫秒,預設值為-1,表示永不超時。如果超過等待時間,則直接丟擲JedisConnectionException;
private static int MAX_WAIT = 10000;
// 過期時間
protected static int expireTime = 60 * 60 *24;
// 連線池
protected static JedisPool pool;
/**
* 靜態程式碼,只在初次呼叫一次
*/
static {
JedisPoolConfig config = new JedisPoolConfig();
//最大連線數
config.setMaxTotal(MAX_ACTIVE);
//最多空閒例項
config.setMaxIdle(MAX_IDLE);
//超時時間
config.setMaxWaitMillis(MAX_WAIT);
//
config.setTestOnBorrow(false);
pool = new JedisPool(config, ADDR, PORT, 1000);
}
/**
* 獲取jedis例項
*/
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;
}
/**
* 釋放jedis資源
*
* @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;
}
/**
* 刪除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;
}
/**
* 新增string資料
*
* @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;
}
/**
* 新增hash資料
*
* @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);
}
}
}
注意:1,客戶端的Jedis連線不同於專案裡的Jedis連線需要Spring註解,直接使用靜態方法就可以。
執行
1,執行canal服務端startup.bat / startup.sh
2,執行客戶端程式
注意
1,雖然canal服務端解析binlog後不會把資料持久化,但canal服務端會記錄每次客戶端消費的位置(客戶端每次ack時服務端會記錄pos點)。如果資料正在更新時,canal服務端掛掉,客戶端也會跟著掛掉,mysql依然在插入資料,而redis則因為客戶端的關閉而停止更新,造成mysql和redis的資料不一致。解決辦法是,只要重啟canal服務端和客戶端就可以了,雖然canal服務端因為重啟之前解析資料清空,但因為canal服務端記錄的是客戶端最後一次獲取的pos點,canal服務端再從這個pos點開始解析,客戶端更新至redis,以達到資料的一致。
2,如果只有一個canal服務端和一個客戶端,肯定存在可用性低的問題,一種做法是用程式來監控canal服務端和客戶端,如果掛掉,再重啟;一種做法是多個canal服務端+zk,將canal服務端的配置檔案放在zk,任何一個canal服務端掛掉後,切換到其他canal服務端,讀到的配置檔案的內容就是一致的(還有記錄的消費pos點),保證業務的高可用,客戶端可使用相同的做法。
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