ClickHouse作为OLAP分析引擎已经被广泛使用，数据的导入导出是用户面临的第一个问题。由于ClickHouse本身无法很好地支持单条大批量的写入，因此在实时同步数据方面需要借助其他服务协助。本文给出一种结合Canal+Kafka的方案，并且给出在多个MySQL实例分库分表的场景下，如何将多张MySQL数据表写入同一张ClickHouse表的方法，欢迎大家批评指正
我的需求就是将mysql多张表的数据实时同步到clickhouse中，参考了很多网上的资料，写的都不是很好，有的配置完成后，就会报错，今天终于实现了该功能，分享给大家。
我主要利用canal来实现ClickHouse实时同步MySQL数据，本次不考虑接入kafka等mq
- 配置mysql
- canal安装配置
- canal-client安装配置
- 创建clickhouse的数据库和表
- 结果展示
1. 配置mysql
开启binlog
# mysql配置文件/etc/my.cnf添加下面配置
vi /etc/my.cnf
#插入下面内容
server-id = 1
log_bin = /var/lib/mysql/bin.log
binlog-format = row # very important if you want to receive write, update and delete row events
# optional
expire_logs_days = 30
max_binlog_size = 768M
# setup listen address
bind-address = 0.0.0.0
新增同步账号
#登陆mysql,执行下面命令，创建账号aaa，密码为123456
CREATE USER 'maxwell'@'%' IDENTIFIED BY '123456';
GRANT SELECT, REPLICATION CLIENT, REPLICATION SLAVE ON *.* TO 'maxwell'@'%';
flush privileges;
2. canal安装配置
下载 canal, 访问 release页面 , 选择需要的包下载, 如以 1.1.4 版本为例
#下载canalan安装包
wget https://github.com/alibaba/canal/releases/download/canal-1.1.4/canal.deployer-1.1.4.tar.gz
#解压到指定目录
mkdir -p /usr/tool/canal
tar zxvf canal.deployer-1.1.4.tar.gz -C /usr/tool/canal
#解压后进入目录，结构如下
drwxr-xr-x 7 awwzc staff 238 12 14 23:34 bin
drwxr-xr-x 9 awwzc staff 306 12 14 23:32 conf
drwxr-xr-x 83 awwzc staff 2822 12 14 23:30 lib
drwxr-xr-x 4 awwzc staff 136 12 14 23:34 logs
# canal启动时会读取conf目录下面的文件夹，当作instance,进入conf目录下复制example文件夹
cp -R example／ maxwell/
#移除example文件夹
mv -rf example
#修改canal.properties(一定要修改)
# instance列表，conf目录下必须有同名的目录
canal.destinations = maxwell
#修改maxwell文件夹下面的instance.properties文件下面几项为你自己的数据库配置即可
vi conf/maxwell/instance.properties
# position info
canal.instance.master.address=192.168.0.102:3306
# username/password
canal.instance.dbUsername=maxwell
canal.instance.dbPassword=123456
# 启动，安装目录下执行以下命令,server,instance出现下面日记说明启动成功
bin/startup.sh
# 查看server日记，会出现以下日记
tail -200f logs/canal/canal.log
2019-12-14 23:34:47.247 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## set default uncaught exception handler
2019-12-14 23:34:47.312 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## load canal configurations
2019-12-14 23:34:47.334 [main] INFO com.alibaba.otter.canal.deployer.CanalStarter - ## start the canal server.
2019-12-14 23:34:47.406 [main] INFO com.alibaba.otter.canal.deployer.CanalController - ## start the canal server[192.168.0.111(192.168.0.111):11111]
2019-12-14 23:34:49.026 [main] INFO com.alibaba.otter.canal.deployer.CanalStarter - ## the canal server is running now ......
# 查看instance日记，会出现以下日记
tail -200f logs/maxwell/maxwell.log
2019-12-15 17:59:12.908 [destination = example , address = /192.168.0.102:3306 , EventParser] WARN c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - ---> begin to find start position, it will be long time for reset or first position
2019-12-15 17:59:12.913 [destination = example , address = /192.168.0.102:3306 , EventParser] WARN c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - prepare to find start position just last position
{"identity":{"slaveId":-1,"sourceAddress":{"address":"192.168.0.102","port":3306}},"postion":{"gtid":"","included":false,"journalName":"bin.000002","position":249315,"serverId":1,"timestamp":1576282583000}}
2019-12-15 17:59:13.015 [destination = example , address = /192.168.0.102:3306 , EventParser] WARN c.a.o.c.p.inbound.mysql.rds.RdsBinlogEventParserProxy - ---> find start position successfully, EntryPosition[included=false,journalName=bin.000002,position=249315,serverId=1,gtid=,timestamp=1576282583000] cost : 105ms , the next step is binlog dump
#关闭
sh bin/stop.sh
3. canal-client安装配置
下载 canal-adapter, 访问 release页面 , 选择需要的包下载, 如以 1.1.4 版本为例
#下载
wget https://github.com/alibaba/canal/releases/download/canal-1.1.4/canal.adapter-1.1.4.tar.gz
#解压
mkdir -p /usr/tool/canal-adapter
tar zxvf canal.adapter-1.1.4.tar.gz -C /usr/tool/canal-adapter
#解压后目录如下
drwxr-xr-x 7 awwzc staff 238 12 15 13:19 bin
drwxr-xr-x 9 awwzc staff 306 12 15 13:18 conf
drwxr-xr-x 87 awwzc staff 2958 12 15 13:18 lib
drwxr-xr-x 3 awwzc staff 102 12 15 13:19 logs
drwxr-xr-x 6 awwzc staff 204 12 15 13:09 plugin
#在lib目录下面添加clickhouse连接驱动
httpcore-4.4.13.jar、httpclient-4.3.3.jar、clickhouse-jdbc-0.2.4.jar；
#修改配置文件conf/application.yml文件，修改canalServerHost、srcDataSources、canalAdapters的配置；
canal.conf:
mode: tcp
canalServerHost: 127.0.0.1:11111 # canal-server的服务地址
secretKey:
#同步数据源配置
srcDataSources
defaultDS:
#mysql连接信息
url: jdbc:mysql://192.168.0.102:3306/maxwell?useUnicode=true
username: root
password: 123456
canalAdapters:
- instance: maxwell # canal instance Name or mq topic name
groups:
- groupId: g1
outerAdapters:
- name: logger
- name: rdb #rdb类型
key: mysql
properties:
#clickhouse数据看配置
jdbc.driverClassName: ru.yandex.clickhouse.ClickHouseDriver
jdbc.url: jdbc:clickhouse://127.0.0.1:8123/maxwell
jdbc.username: default
jdbc.password:
1. 源数据库与目标数据库名字不同，源表名与目标表名不同
#修改adapter的conf/rdb/mytest_user.yml配置文件，指定源数据库和目标数据库
dataSourceKey: defaultDS
destination: maxwell
groupId: g1
outerAdapterKey: mysql1
concurrent: true
dbMapping:
database: aqi_china
table: tb_aqi_0
targetTable: aqi_china.tb_aqi
#targetPk:
# id: id
mapAll: true
#targetColumns:
# id:
# name:
# role_id:
# c_time:
# test1:
#etlCondition: "where c_time>={}"
commitBatch: 3000 # 批量提交的大小
2. 多个源数据库表写入目的端的同一张表
在conf/rdb 目录配置多个yml文件，分别指明不同的table名称。
启动
bin/startup.sh
#查看日记，出现以下日记说名启动成功
tail -200f logs/adapter/adapter.log
我在启动的时候出现了内存溢出的异常，可以通过修改startup.sh的配置：
启动后需要看日志，成功启动后会打印：
2019-12-15 13:19:40.457 [main] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterService - ## start the canal client adapters.
2019-12-15 13:19:40.464 [main] INFO c.a.otter.canal.client.adapter.support.ExtensionLoader - extension classpath dir: /Users/awwzc/Documents/my_soft/tool/canal-adpater/plugin
2019-12-15 13:19:40.542 [main] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterLoader - Load canal adapter: logger succeed
2019-12-15 13:19:40.546 [main] INFO c.a.otter.canal.client.adapter.rdb.config.ConfigLoader - ## Start loading rdb mapping config ...
2019-12-15 13:19:40.637 [main] INFO c.a.otter.canal.client.adapter.rdb.config.ConfigLoader - ## Rdb mapping config loaded
2019-12-15 13:19:40.640 [main] ERROR com.alibaba.druid.pool.DruidDataSource - testWhileIdle is true, validationQuery not set
2019-12-15 13:19:40.951 [main] INFO com.alibaba.druid.pool.DruidDataSource - {dataSource-2} inited
2019-12-15 13:19:40.959 [main] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterLoader - Load canal adapter: rdb succeed
2019-12-15 13:19:40.986 [main] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterLoader - Start adapter for canal instance: example succeed
2019-12-15 13:19:40.986 [Thread-4] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Start to connect destination: example <=============
2019-12-15 13:19:40.986 [main] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterService - ## the canal client adapters are running now ......
2019-12-15 13:19:40.995 [main] INFO org.apache.coyote.http11.Http11NioProtocol - Starting ProtocolHandler ["http-nio-8081"]
2019-12-15 13:19:41.021 [main] INFO org.apache.tomcat.util.net.NioSelectorPool - Using a shared selector for servlet write/read
2019-12-15 13:19:41.048 [main] INFO o.s.boot.web.embedded.tomcat.TomcatWebServer - Tomcat started on port(s): 8081 (http) with context path ''
2019-12-15 13:19:41.053 [main] INFO c.a.otter.canal.adapter.launcher.CanalAdapterApplication - Started CanalAdapterApplication in 7.099 seconds (JVM running for 7.832)
2019-12-15 13:19:41.122 [Thread-4] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Start to subscribe destination: example <=============
2019-12-15 13:19:41.128 [Thread-4] INFO c.a.o.canal.adapter.launcher.loader.CanalAdapterWorker - =============> Subscribe destination: example succeed <=============
4. clickhouse创建数据库和表
#创建数据库
CREATE DATABASE aqi_china;
#创建表
CREATE TABLE IF NOT EXISTS aqi_china.tb_aqi (id Int32,uuid String,uid Int32,aqi Int32,url String,co String,dew String,h String,no2 String,o3 String,p String,pm10 String,pm25 String,so2 String,t String,w String,wg String,vtime String,ftime Int32) ENGINE=MergeTree() PARTITION BY uid ORDER BY id SETTINGS index_granularity = 8192;
5. 结果展示
我们来看一下展示结果：
这是canal客户端打印的日志：
展示clickhouse的数据：
数据已经同步成功了
希望可以帮助到跟我遇到同样问题的同学，这个方式肯定没问题，如果有问题，可以给我留言
