阿里Canal中間件搭建及使用

說明：

canal [kə'næl]，譯意爲水道/管道/溝渠，主要用途是基於 MySQL 數據庫增量日誌解析，提供增量數據訂閱和消費

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。

基於日誌增量訂閱和消費的業務包括

數據庫鏡像
數據庫實時備份
索引構建和實時維護(拆分異構索引、倒排索引等)
業務 cache 刷新
帶業務邏輯的增量數據處理

1. 環境部署

1.1 mysql開啓binlog模式

（1）查看當前mysql是否開啓binlog模式。

[root@localhost opt]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.28 MySQL Community Server (GPL)

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SHOW VARIABLES LIKE '%log_bin%';
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| log_bin                         | OFF   |
| log_bin_basename                |       |
| log_bin_index                   |       |
| log_bin_trust_function_creators | OFF   |
| log_bin_use_v1_row_events       | OFF   |
| sql_log_bin                     | ON    |
+---------------------------------+-------+
6 rows in set (0.03 sec)

如果log_bin的值爲OFF是未開啓，爲ON是已開啓。

（2）修改/etc/my.cnf 需要開啓binlog模式。

[mysqld]
log-bin=mysql-bin
binlog-format=ROW
server_id=1

修改完成之後，重啓mysqld的服務。

[root@localhost opt]# vim /etc/my.cnf
[root@localhost opt]# systemctl restart mysqld

（3）查詢是否開啓成功。

[root@localhost opt]# mysql -h localhost -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.28-log MySQL Community Server (GPL)

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SHOW VARIABLES LIKE '%log_bin%';
+---------------------------------+--------------------------------+
| Variable_name                   | Value                          |
+---------------------------------+--------------------------------+
| log_bin                         | ON                             |
| log_bin_basename                | /var/lib/mysql/mysql-bin       |
| log_bin_index                   | /var/lib/mysql/mysql-bin.index |
| log_bin_trust_function_creators | OFF                            |
| log_bin_use_v1_row_events       | OFF                            |
| sql_log_bin                     | ON                             |
+---------------------------------+--------------------------------+
6 rows in set (0.02 sec)

1.2 創建賬號用於測試使用

使用root賬號創建用戶並授予權限；

create user canal@'%' IDENTIFIED by 'canal';
GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT,SUPER ON *.* TO 'canal'@'%';
FLUSH PRIVILEGES;

1.3 canal服務端安裝配置

附：canal下載地址

1.3.1 進入canal文件夾，修改配置文件

vi conf/example/instance.properties

#################################################
## mysql serverId , v1.0.26+ will autoGen
# canal.instance.mysql.slaveId=0

# enable gtid use true/false
canal.instance.gtidon=false

# position info
canal.instance.master.address=127.0.0.1:3306
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
canal.instance.dbUsername=canal
canal.instance.dbPassword=canal
canal.instance.connectionCharset = UTF-8
# enable druid Decrypt database password
canal.instance.enableDruid=false
#canal.instance.pwdPublicKey=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALK4BUxdDltRRE5/zXpVEVPUgunvscYFtEip3pmLlhrWpacX7y7GCMo2/JM6LeHmiiNdH1FWgGCpUfircSwlWKUCAwEAAQ==

# table regex
canal.instance.filter.regex=.*\\..*
# table black regex
canal.instance.filter.black.regex=
# table field filter(format: schema1.tableName1:field1/field2,schema2.tableName2:field1/field2)
#canal.instance.filter.field=test1.t_product:id/subject/keywords,test2.t_company:id/name/contact/ch
# table field black filter(format: schema1.tableName1:field1/field2,schema2.tableName2:field1/field2)
#canal.instance.filter.black.field=test1.t_product:subject/product_image,test2.t_company:id/name/contact/ch

# mq config
canal.mq.topic=example
# dynamic topic route by schema or table regex
#canal.mq.dynamicTopic=mytest1.user,mytest2\\..*,.*\\..*
canal.mq.partition=0
# hash partition config
#canal.mq.partitionsNum=3
#canal.mq.partitionHash=test.table:id^name,.*\\..*
#################################################

ps:

(1)#canal.instance.defaultDatabaseName 1.1.5版本配置文件中並沒有這個參數，低版本有；一定要註釋掉下面這個參數，這樣就會掃描全庫；這裏的配置文件我並未修改，我的mysql與canal在同一服務器，賬號密碼也是canal；

(2)#需要改成同步的數據庫表規則，例如只是同步一下表

#canal.instance.filter.regex=.*\\..*

canal.instance.filter.regex=test.canal

(3)mysql 數據解析關注的表，Perl正則表達式.

mysql 數據解析關注的表，Perl正則表達式.
多個正則之間以逗號(,)分隔，轉義符需要雙斜槓(\\) 
常見例子：
1.  所有表：.*   or  .*\\..*
2.  canal schema下所有表： canal\\..*
3.  canal下的以canal打頭的表：canal\\.canal.*
4.  canal schema下的一張表：canal.test1
5.  多個規則組合使用：canal\\..*,mysql.test1,mysql.test2 (逗號分隔)
注意：此過濾條件只針對row模式的數據有效(ps. mixed/statement因爲不解析sql，所以無法準確提取tableName進行過濾)

1.3.2 啓動服務：

[root@localhost canal]# ./bin/startup.sh

1.3.3 查看日誌：

cat /usr/local/canal/logs/canal/canal.log

2. 後臺代碼

package com.lucifer;
import java.net.InetSocketAddress;
import java.util.List;


import com.alibaba.otter.canal.client.CanalConnectors;
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;

public class TestCanal {


    public static void main(String args[]) {
        // 創建鏈接
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.160.130",
                11111), "example", "", "");
        int batchSize = 1000;
        int emptyCount = 0;
        try {
            connector.connect();
            connector.subscribe(".*\\..*");
            connector.rollback();
            int totalEmptyCount = 120;
            while (emptyCount < totalEmptyCount) {
                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) {
                    emptyCount++;
                    System.out.println("empty count : " + emptyCount);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                    }
                } else {
                    emptyCount = 0;
                    // System.out.printf("message[batchId=%s,size=%s] \n", batchId, size);
                    printEntry(message.getEntries());
                }

                connector.ack(batchId); // 提交確認
                // connector.rollback(batchId); // 處理失敗, 回滾數據
            }

            System.out.println("empty too many times, exit");
        } 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("================&gt; 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) {
                    printColumn(rowData.getBeforeColumnsList());
                } else if (eventType == EventType.INSERT) {
                    printColumn(rowData.getAfterColumnsList());
                } else {
                    System.out.println("-------&gt; before");
                    printColumn(rowData.getBeforeColumnsList());
                    System.out.println("-------&gt; after");
                    printColumn(rowData.getAfterColumnsList());
                }
            }
        }
    }

    private static void printColumn(List<Column> columns) {
        for (Column column : columns) {
            System.out.println(column.getName() + " : " + column.getValue() + "    update=" + column.getUpdated());
        }
    }
}

首先啓動Canal Server；啓動Canal Client後，可以從控制檯從看到類似消息：

empty count : 1
empty count : 2
empty count : 3
empty count : 4
empty count : 5
empty count : 6

此時代表當前數據庫無變更數據。

創建數據庫test，創建數據庫表canal：

CREATE TABLE `canal` (
  `id` int(11) NOT NULL,
  `name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

通過navicat新增一條數據後，控制檯打印：

================&gt; binlog[mysql-bin.000001:2137] , name[test,canal] , eventType : INSERT
id : 1    update=true
name : 張三    update=true

通過navicat修改一條數據後，控制檯打印：

================&gt; binlog[mysql-bin.000001:2404] , name[test,canal] , eventType : UPDATE
-------&gt; before
id : 1    update=false
name : 張三    update=false
-------&gt; after
id : 1    update=false
name : 李四    update=true

阿里Canal中間件搭建及使用

說明：

1. 環境部署

1.1 mysql開啓binlog模式

1.2 創建賬號用於測試使用

1.3 canal服務端安裝配置

ps:

2. 後臺代碼

HTTP URL 詳解

【Sharding-JDBC】（一）整合mybatis-plus 水平分表

【Sharding-JDBC】（三）整合mybatis-plus 水平分庫、分表

【Sharding-JDBC】（二）整合mybatis-plus 一主一從讀寫分離

MySQL5.7 主從同步環境搭建

【RocketMQ】（一）簡單消息（可靠的同步，可靠的異步和單向傳輸）

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

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阿里Canal中間件搭建及使用

說明：

1. 環境部署

1.1 mysql開啓binlog模式

1.2 創建賬號 用於測試使用

1.3 canal服務端安裝配置

ps:

2. 後臺代碼

1.2 創建賬號用於測試使用