最近有個需求,需要將一張表同步redis,
找到了CANAL,又是阿里開發的,下面是官方介紹
開發背景
早期阿里巴巴因爲杭州和美國雙機房部署,存在跨機房同步的業務需求,實現方式主要是基於業務 trigger 獲取增量變更。從 2010 年開始,業務逐步嘗試數據庫日誌解析獲取增量變更進行同步,由此衍生出了大量的數據庫增量訂閱和消費業務
如上面圖片意思,大概CANAL相當於一個從機,監聽訂閱了主機MYSQL的binary log隊列,
當主機MYSQL有數據變化時,CANAL會馬上知道,然後獲得記錄,你就可以開始的業務需求了
可以同步MYSQL,插入隊列,ES等,是不是很強大。
網上最新的是 1.1.4的版本,而且阿里還再1.1.4版本提供的前端代碼,終結了黑屏操作,但是資料甚少,
本節還是用的1.1.3版本。
git地址: https://github.com/alibaba/canal
下面是測試步驟。
1, 數據庫開啓binlog模式。並重啓mysql,使之有效
log_bin=mysql-bin #指定bin-log的名稱,儘量可以標識業務含義
binlog_format=row #選擇row模式,必須!!!
server_id=1 #mysql服務器id
2,建立個mysql用戶,給CANAL訂閱用
mysql> CREATE USER 'canal'@'%' IDENTIFIED BY 'canal';
mysql> GRANT ALL ON canal.* TO 'canal'@'%';
mysql> GRANT SELECT, REPLICATION CLIENT, REPLICATION SLAVE ON *.* TO 'canal'@'%';
mysql>FLUSH PRIVILEGES;
3,下載1.1.3tar包,地址 https://github.com/alibaba/canal/releases/tag/canal-1.1.3
4,解壓文件 tar xzvf canal.deployer-1.1.3.tar.gz -C canal
5,修改CANAL的instance.properties文件 再canal/conf/example目錄下
5,啓動CANAL
canal/bin/start.sh
查看日誌 canal/logs/example
find start position successfully, EntryPosition[included=false,journalName=mysql-bin.000001,position=6337,serverId=1,gtid=,timestamp=1573609267000] cost : 9ms , the next step is binlog dump
這個就是啓動成功了
6,編寫CACAL的client端
6.1 引入pom
<dependency>
<groupId>com.alibaba.otter</groupId>
<artifactId>canal.client</artifactId>
<version>1.1.3</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.4.2</version>
</dependency>
6.2 寫客戶端類
import com.alibaba.fastjson.JSONObject;
import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.protocol.CanalEntry.*;
import com.alibaba.otter.canal.protocol.Message;
import com.shrek.canal.util.RedisUtil;
import java.net.InetSocketAddress;
import java.util.List;
public class CanalClientTest{
public static void main(String args[]) {
CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.233.107",
11111), "example", "", "");
int batchSize = 1000;
try {
connector.connect();
connector.subscribe(".*\\..*");
connector.rollback();
while (true) {
Message message = connector.getWithoutAck(batchSize); // 獲取指定數量的數據
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, 回滾數據
}
} 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");
printColumn(rowData.getAfterColumnsList());
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());
}
}
}
6.3 因爲我是同步到redis,需要redis工具類
import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; public class RedisUtil { // Redis服務器IP private static String ADDR = "192.168.233.106"; // Redis的端口號 private static int PORT = 6379; // 訪問密碼 //private static String AUTH = "admin"; // 可用連接實例的最大數目,默認值爲8; // 如果賦值爲-1,則表示不限制;如果pool已經分配了maxActive個jedis實例,則此時pool的狀態爲exhausted(耗盡)。 private static int MAX_ACTIVE = 1024; // 控制一個pool最多有多少個狀態爲idle(空閒的)的jedis實例,默認值也是8。 private static int MAX_IDLE = 200; // 等待可用連接的最大時間,單位毫秒,默認值爲-1,表示永不超時。如果超過等待時間,則直接拋出JedisConnectionException; private static int MAX_WAIT = 10000; // 過期時間 protected static int expireTime = 60 * 60 *24; // 連接池 protected static JedisPool pool; /** * 靜態代碼,只在初次調用一次 */ static { JedisPoolConfig config = new JedisPoolConfig(); //最大連接數 config.setMaxTotal(MAX_ACTIVE); //最多空閒實例 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實例 */ 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; } /** * 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(2); 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(2); 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(2); lastVal = jedis.get(key); jedis.expire(key, expireTime); } catch (Exception e) { isBroken = true; } finally { closeResource(jedis, isBroken); } return lastVal; } /** * 添加string數據 * @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(2); 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數據 * @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(2); jedis.hset(key, field, value); jedis.expire(key, expireTime); } } catch (Exception e) { isBroken = true; } finally { closeResource(jedis, isBroken); } } }
效果:
修改數據庫時,CLIENT客戶端馬上可以收到消息
然後立馬同步到redis,基本上是實時的了