前言
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种一棵树最好的时间是十年前，其次是现在
絮叨
Redis系列写完了，好好学习看看，各位应该可以入个门
这篇讲 数据同步 cannl,因为Redis中有一个知识点：如何保证缓存一致，有说到用canal做一个补偿机制，刚好自己也不会，就带大家一起学习，学习,绝对是从0开始
什么是canal
canal是纯Java开发。基于数据库增量日志解析，提供增量数据订阅&消费，目前主要支持了MySQL
如上图：canal 模拟 MySQL slave 的交互协议，伪装自己为 MySQL slave ，向 MySQL master 发送dump 协议
canal 搭建
搭建mysql环境
- 对于自建 MySQL , 需要先开启 Binlog 写入功能，配置 binlog-format 为 ROW 模式，my.cnf 中配置如下
[mysqld] log-bin=mysql-bin # 开启 binlog binlog-format=ROW # 选择 ROW 模式 server_id=1 # 配置 MySQL replaction 需要定义，不要和 canal 的 slaveId 重复 复制代码
- 授权 canal 链接 MySQL 账号具有作为 MySQL slave 的权限, 如果已有账户可直接 grant
CREATE USER canal IDENTIFIED BY 'canal'; GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%'; -- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ; FLUSH PRIVILEGES; 复制代码
这个第一步还是蛮简单的，就是要自己搭建一个mysql，修改一下mysql的配置,这个配置一般是再/etc/my.cnf中，还是得要点小基础的哈，至少mysql得会搭
搭建canal环境
- 下载 canal, 访问 release 页面 , 选择需要的包下载, 如以 1.0.17 版本为例
wget https://github.com/alibaba/canal/releases/download/canal-1.0.17/canal.deployer-1.0.17.tar.gz 复制代码
- 解压缩
mkdir /tmp/canal tar zxvf canal.deployer-$version.tar.gz -C /tmp/canal 复制代码
解压完成后，进入 /tmp/canal 目录，可以看到如下结构
- 配置修改
vi conf/example/instance.properties 复制代码
################################################# ## mysql serverId , v1.0.26+ will autoGen canal.instance.mysql.slaveId=8 # enable gtid use true/false canal.instance.gtidon=false # position info 需要改成自己的数据库信息 canal.instance.master.address=10.0.98.186:3306 canal.instance.master.journal.name= canal.instance.master.position= canal.instance.master.timestamp= canal.instance.master.gtid= # rds oss binlog canal.instance.rds.accesskey= canal.instance.rds.secretkey= canal.instance.rds.instanceId= # table meta tsdb info canal.instance.tsdb.enable=true #canal.instance.tsdb.url=jdbc:mysql://127.0.0.1:3306/canal_tsdb #canal.instance.tsdb.dbUsername=canal #canal.instance.tsdb.dbPassword=canal #canal.instance.standby.address = #canal.instance.standby.journal.name = #canal.instance.standby.position = #canal.instance.standby.timestamp = #canal.instance.standby.gtid= # username/password 需要改成自己的数据库信息 canal.instance.dbUsername=root canal.instance.dbPassword=root canal.instance.connectionCharset=UTF-8 canal.instance.defaultDatabaseName=expert-online-school # table regex canal.instance.filter.regex=.*\\..* # table black regex canal.instance.filter.black.regex= ################################################# 复制代码
注意： canal.instance.connectionCharset 代表数据库的编码方式对应到 java 中的编码类型，比如 UTF-8，GBK , ISO-8859-1 如果系统是1个 cpu，需要将 canal.instance.parser.parallel 设置为 false
- 启动
sh bin/startup.sh 复制代码
到目前为止 canal的服务端我们已经搭建好了 但是到目前 我们只是把数据库的binlog 拉到canal中，我们还得把数据用otter去消费
写个简单的Demo 去监听mysql 数据的变动
Jar包
<dependency> <groupId>com.alibaba.otter</groupId> <artifactId>canal.client</artifactId> <version>1.1.3</version> </dependency> 复制代码
测试代码
package com.hq.eos.sync.client; import java.net.InetSocketAddress; import java.util.List; import com.alibaba.otter.canal.client.CanalConnector; import com.alibaba.otter.canal.client.CanalConnectors; 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.protocol.Message; public class CanalTest { public static void main(String[] args) throws Exception { CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("10.0.98.186", 11111), "expert", "root", "root"); connector.connect(); connector.subscribe(".*\\..*"); connector.rollback(); while (true) { Message message = connector.getWithoutAck(100); // 获取指定数量的数据 long batchId = message.getId(); if (batchId == -1 || message.getEntries().isEmpty()) { Thread.sleep(1000); continue; } // System.out.println(message.getEntries()); printEntries(message.getEntries()); connector.ack(batchId);// 提交确认，消费成功，通知server删除数据 // connector.rollback(batchId);// 处理失败, 回滚数据，后续重新获取数据 } } private static void printEntries(List<Entry> entries) throws Exception { for (Entry entry : entries) { if (entry.getEntryType() != EntryType.ROWDATA) { continue; } RowChange rowChange = RowChange.parseFrom(entry.getStoreValue()); EventType eventType = rowChange.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 : rowChange.getRowDatasList()) { switch (rowChange.getEventType()) { case INSERT: System.out.println("INSERT "); printColumns(rowData.getAfterColumnsList()); break; case UPDATE: System.out.println("UPDATE "); printColumns(rowData.getAfterColumnsList()); break; case DELETE: System.out.println("DELETE "); printColumns(rowData.getBeforeColumnsList()); break; default: break; } } } } private static void printColumns(List<Column> columns) { for(Column column : columns) { System.out.println(column.getName() + " : " + column.getValue() + " update=" + column.getUpdated()); } } } 复制代码
测试结果
================> binlog[mysql-bin.000017:240485980] , name[xxl_job,xxl_job_registry] , eventType : UPDATE UPDATE id : 402 update=false registry_group : EXECUTOR update=false registry_key : hq-eos-crawler update=false registry_value : 172.27.0.1:15674 update=false update_time : 2019-12-03 17:54:42 update=true ================> binlog[mysql-bin.000017:240486374] , name[xxl_job,xxl_job_registry] , eventType : UPDATE UPDATE id : 82 update=false registry_group : EXECUTOR update=false registry_key : hq-eos-inf-config update=false registry_value : 172.18.0.1:15672 update=false update_time : 2019-12-03 17:54:42 update=true ================> binlog[mysql-bin.000017:240486774] , name[xxl_job,xxl_job_registry] , eventType : UPDATE 复制代码
注意一下
CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("10.0.98.186", 11111), "expert", "root", "root"); 复制代码
这里的配置来自于 canal.properties 我把这个配置也贴出来吧
canal.id= 8 canal.ip= canal.port=11111 canal.metrics.pull.port=11112 canal.zkServers=10.0.14.36:2181,10.0.14.39:2181,10.0.14.49:2181 # flush data to zk canal.zookeeper.flush.period = 1000 canal.withoutNetty = false # flush meta cursor/parse position to file canal.file.data.dir = ${canal.conf.dir} canal.file.flush.period = 1000 ## memory store RingBuffer size, should be Math.pow(2,n) canal.instance.memory.buffer.size = 16384 ## memory store RingBuffer used memory unit size , default 1kb canal.instance.memory.buffer.memunit = 1024 ## meory store gets mode used MEMSIZE or ITEMSIZE canal.instance.memory.batch.mode = MEMSIZE ## detecing config canal.instance.detecting.enable = false #canal.instance.detecting.sql = insert into retl.xdual values(1,now()) on duplicate key update x=now() canal.instance.detecting.sql = select 1 canal.instance.detecting.interval.time = 3 canal.instance.detecting.retry.threshold = 3 canal.instance.detecting.heartbeatHaEnable = false # support maximum transaction size, more than the size of the transaction will be cut into multiple transactions delivery canal.instance.transaction.size = 1024 # mysql fallback connected to new master should fallback times canal.instance.fallbackIntervalInSeconds = 60 # network config canal.instance.network.receiveBufferSize = 16384 canal.instance.network.sendBufferSize = 16384 canal.instance.network.soTimeout = 30 # binlog filter config canal.instance.filter.druid.ddl = true canal.instance.filter.query.dcl = false canal.instance.filter.query.dml = false canal.instance.filter.query.ddl = false canal.instance.filter.table.error = false canal.instance.filter.rows = false canal.instance.filter.transaction.entry = false # binlog format/image check canal.instance.binlog.format = ROW,STATEMENT,MIXED canal.instance.binlog.image = FULL,MINIMAL,NOBLOB # binlog ddl isolation canal.instance.get.ddl.isolation = false # parallel parser config canal.instance.parser.parallel = true ## concurrent thread number, default 60% available processors, suggest not to exceed Runtime.getRuntime().availableProcessors() #canal.instance.parser.parallelThreadSize = 16 ## disruptor ringbuffer size, must be power of 2 canal.instance.parser.parallelBufferSize = 256 # table meta tsdb info canal.instance.tsdb.enable=true canal.instance.tsdb.dir=${canal.file.data.dir:../conf}/${canal.instance.destination:} canal.instance.tsdb.url=jdbc:h2:${canal.instance.tsdb.dir}/h2;CACHE_SIZE=1000;MODE=MYSQL; canal.instance.tsdb.dbUsername=root canal.instance.tsdb.dbPassword=root # rds oss binlog account canal.instance.rds.accesskey = canal.instance.rds.secretkey = ################################################# ######### destinations ############# ################################################# canal.destinations= expert # conf root dir canal.conf.dir = ../conf # auto scan instance dir add/remove and start/stop instance canal.auto.scan = true canal.auto.scan.interval = 5 canal.instance.tsdb.spring.xml=classpath:spring/tsdb/h2-tsdb.xml #canal.instance.tsdb.spring.xml=classpath:spring/tsdb/mysql-tsdb.xml canal.instance.global.mode = spring canal.instance.global.lazy = false #canal.instance.global.manager.address = 127.0.0.1:1099 #canal.instance.global.spring.xml = classpath:spring/memory-instance.xml canal.instance.global.spring.xml = classpath:spring/file-instance.xml #canal.instance.global.spring.xml = classpath:spring/default-instance.xml 复制代码
这上面很多配置这边就不一一说明了 zookeeper的话是做instance 集群的时候用的
结尾
canal入门写完，谢谢大家的支持，大家如果想学后面一篇文章，一定要把这个照着做一遍。
因为博主也是一个开发萌新 我也是一边学一边写 我有个目标就是一周 二到三篇 希望能坚持个一年吧 希望各位大佬多提意见，让我多学习，一起进步。
