数据传输 | 如何使用 DTLE 将 Oracle 数据同步到 MySQL

作者：刘安

爱可生测试团队成员，主要负责 DTLE 开源项目相关测试任务，擅长 Python 自动化测试开发。

本文来源：原创投稿

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前言：过年前 DTLE 发布了 4.22.01.0 版本，该版本最重要的特性是支持 Oracle-MySQL 增量数据同步。今天我就来给大家介绍一下这个功能。

一、现状

1. 目前只支持增量同步

a. 可以根据 SCN 节点开启增量复制

b. 从任务启动时间开启增量复制

2. 类型映射

a. 已支持类型

b. 待支持类型

c. 不支持类型

3. DML支持度

a. DML类型

b. DML函数支持度

4. DDL支持度

二、环境准备

1. Oracle数据库开启归档日志

shell> su oracle
shell> mkdir /u01/app/oracle/oradata/archive_log
shell> sqlplus sys/oracle as sysdba

SQL> alter system set log_archive_dest_1='location=/u01/app/oracle/oradata/archive_log' scope=spfile;
SQL> alter system set db_recovery_file_dest_size = 10G;
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database add logfile group 3 '/u01/app/oracle/fast_recovery_area/XE/onlinelog/redo01.log' size 500m;
SQL> alter database add logfile group 4 '/u01/app/oracle/fast_recovery_area/XE/onlinelog/redo02.log' size 500m;
SQL> alter database add logfile group 5 '/u01/app/oracle/fast_recovery_area/XE/onlinelog/redo03.log' size 500m;
SQL> alter database archivelog;
SQL> alter database add supplemental log data (all) columns;
SQL> alter database open;
SQL> archive log list;
# Archive Mode表示已开启归档模式，Archive destination表示归档日志储存路径

2. 安装 LogMiner 工具（Oracle 安装时默认安装）

可查看系统中是否存在运行 LogMiner 所需要的 dbms_logmnr 、dbms_logmnr_d 包，如果没有安装 LogMiner 工具需要的包，需要运行下面两个命令：

shell> cat $ORACLE_HOME/rdbms/admin/dbmslm.sql | sqlplus sys/oracle as sysdba
shell> cat $ORACLE_HOME/rdbms/admin/dbmslmd.sql | sqlplus sys/oracle as sysdba

3. 创建 logminer 需要角色权限

shell> su oracle
shell> sqlplus sys/oracle as sysdba

SQL> create user roma_logminer identified by oracle default tablespace users;

SQL> GRANT CREATE SESSION TO roma_logminer;
SQL> GRANT SET CONTAINER TO roma_logminer;
SQL> GRANT SELECT ON V_$DATABASE TO roma_logminer;
SQL> GRANT FLASHBACK ANY TABLE TO roma_logminer;
SQL> GRANT SELECT ANY TABLE TO roma_logminer;
SQL> GRANT SELECT_CATALOG_ROLE TO roma_logminer;
SQL> GRANT EXECUTE_CATALOG_ROLE TO roma_logminer;
SQL> GRANT SELECT ANY TRANSACTION TO roma_logminer;
SQL> GRANT CREATE TABLE TO roma_logminer;
SQL> GRANT LOCK ANY TABLE TO roma_logminer;
SQL> GRANT CREATE SEQUENCE TO roma_logminer;
SQL> GRANT EXECUTE ON DBMS_LOGMNR TO roma_logminer;
SQL> GRANT EXECUTE ON DBMS_LOGMNR_D TO roma_logminer;

SQL> GRANT SELECT ON V_$LOG TO roma_logminer;
SQL> GRANT SELECT ON V_$LOG_HISTORY TO roma_logminer;
SQL> GRANT SELECT ON V_$LOGMNR_LOGS TO roma_logminer;
SQL> GRANT SELECT ON V_$LOGMNR_CONTENTS TO roma_logminer;
SQL> GRANT SELECT ON V_$LOGMNR_PARAMETERS TO roma_logminer;
SQL> GRANT SELECT ON V_$LOGFILE TO roma_logminer;
SQL> GRANT SELECT ON V_$ARCHIVED_LOG TO roma_logminer;
SQL> GRANT SELECT ON V_$ARCHIVE_DEST_STATUS TO roma_logminer;

SQL> alter user roma_logminer quota unlimited ON users;

4. 部署一个单节点的 4.22.01.0版本 DTLE

https://github.com/actiontech/dtle/releases/download/v4.22.01.0/dtle-ce-4.22.01.0.x86_64.rpm

三、创建 Oracle-MySQL 任务

1. 获取 Token

shell> curl -s -X POST "http://172.100.9.11:8190/v2/loginWithoutVerifyCode" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"password\": \"admin\", \"tenant\": \"platform\", \"username\": \"admin\"}" | jq
{
  "message": "ok",
  "data": {
    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2NDYxOTE2MzksImdyb3VwIjoicGxhdGZvcm0iLCJuYW1lIjoiYWRtaW4ifQ.-c_jVkxd_vP5Ka3gocdfGZIudWPujutdHpQYx8srX00"
  }
}

2. 准备 job 文件

shell> cat job.json
{
  "job_id": "test_oracle",
  "src_task": {
    "connection_config": {
      "database_type": "Oracle",
      "host": "172.100.9.31",
      "port": 1521,
      "user": "roma_logminer",
      "password": "oracle",
      "service_name": "XE"
    },
    "node_id": "96d28881-f91b-19f4-1614-4d8a0e718e2f",
    "binlog_relay": false,
    "repl_chan_buffer_size": 120,
    "group_max_size": 1,
    "group_timeout": 100,
    "oracle_src_task_config": {
      "scn": 0
    },
    "task_name": "src",
    "replicate_do_db": [
      {
        "table_schema": "ACTION_DB"
      }
    ]
  },
  "is_password_encrypted": false,
  "dest_task": {
    "connection_config": {
      "database_type": "MySQL",
      "host": "172.100.9.1",
      "port": 3306,
      "user": "test_dest",
      "password": "test_dest"
    },
    "node_id": "96d28881-f91b-19f4-1614-4d8a0e718e2f",
    "task_name": "dest",
    "mysql_dest_task_config": {}
  },
  "task_step_name": "job_stage_full",
  "failover": true,
  "retry": 2
}

3. 创建 Oracle-MySQL job

shell> curl -s -X POST "http://172.100.9.11:8190/v2/job/migration/create" -H "accept: application/json" -H "Authorization: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2NDYxOTE2MzksImdyb3VwIjoicGxhdGZvcm0iLCJuYW1lIjoiYWRtaW4ifQ.-c_jVkxd_vP5Ka3gocdfGZIudWPujutdHpQYx8srX00" -H "Content-Type: application/json" -d @job.json | jq
{
  "job": {
    "job_id": "test_oracle-migration",
    "task_step_name": "job_stage_full",
    "reverse": false,
    "failover": true,
    "is_password_encrypted": false,
    "src_task": {
      "task_name": "src",
      "node_id": "96d28881-f91b-19f4-1614-4d8a0e718e2f",
      "replicate_do_db": [
        {
          "table_schema": "ACTION_DB",
          "table_schema_regex": "",
          "table_schema_rename": "",
          "tables": null
        }
      ],
      "replicate_ignore_db": null,
      "skip_create_db_table": false,
      "drop_table_if_exists": false,
      "mysql_src_task_config": null,
      "oracle_src_task_config": {
        "scn": 0
      },
      "group_max_size": 1,
      "group_timeout": 100,
      "repl_chan_buffer_size": 120,
      "chunk_size": 2000,
      "connection_config": {
        "host": "172.100.9.31",
        "port": 1521,
        "user": "roma_logminer",
        "password": "*",
        "service_name": "XE",
        "database_type": "Oracle"
      }
    },
    "dest_task": {
      "task_name": "dest",
      "node_id": "96d28881-f91b-19f4-1614-4d8a0e718e2f",
      "database_type": "",
      "mysql_dest_task_config": {
        "parallel_workers": 1,
        "use_my_sql_dependency": false,
        "dependency_history_size": 2500
      },
      "connection_config": {
        "host": "172.100.9.1",
        "port": 3306,
        "user": "test_dest",
        "password": "*",
        "service_name": "",
        "database_type": "MySQL"
      }
    },
    "retry": 2
  },
  "eval_create_index": 12,
  "job_modify_index": 12,
  "message": "ok"
}

4. 源端 Oracle 写入数据

SQL> create tablespace ACTION_DB datafile 'ACTION_DB.dbf' size 100M;
SQL> create user ACTION_DB identified by ACTION_DB default tablespace ACTION_DB;
SQL> grant unlimited tablespace to ACTION_DB;
SQL> CREATE TABLE ACTION_DB.CHAR_255_COLUMNS(col1 INT, col2 CHAR(255));
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (0, NULL);
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (1, 'abcdefghijklmnopqrstuvwxyz');
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (2, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ');
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (3, '1234567890');
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (4, 1234567890);
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (5, '~`!@#$%^&*()-=_+{}[]|\:;<>,.?/');
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (6, '中文测试abc');
SQL> INSERT INTO ACTION_DB.CHAR_255_COLUMNS VALUES (7, '·~！@#￥%……&*（）-=——+{}【】、|；‘：“，。/《》？');

5. 目标端 MySQL 检查同步情况

mysql> SHOW CREATE TABLE ACTION_DB.CHAR_255_COLUMNS\G
*************************** 1. row ***************************
       Table: CHAR_255_COLUMNS
Create Table: CREATE TABLE `CHAR_255_COLUMNS` (
  `COL1` int(11) DEFAULT NULL,
  `COL2` char(255) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
1 row in set (0.00 sec)

mysql> SELECT * FROM ACTION_DB.CHAR_255_COLUMNS;
+------+-----------------------------------------------------------------------------+
| COL1 | COL2                                                                        |
+------+-----------------------------------------------------------------------------+
|    0 | NULL                                                                        |
|    1 | abcdefghijklmnopqrstuvwxyz                                                  |
|    2 | ABCDEFGHIJKLMNOPQRSTUVWXYZ                                                  |
|    3 | 1234567890                                                                  |
|    4 | 1234567890                                                                  |
|    5 | ~`!@#$%^&*()-=_+{}[]|\:;<>,.?/                                              |
|    6 | 中文测试abc                                                                  |
|    7 | ·~！@#￥%……&*（）-=——+{}【】、|；‘：“，。/《》？                                 |
+------+-----------------------------------------------------------------------------+
8 rows in set (0.01 sec)

四、使用限制

因为 Oracle 和 MySQL 是异构数据库，所以在源端 Oracle 能执行的 Oracle SQL 语句通过 DTLE 转换到目标端的 MySQL SQL 语句后有可能无法正确执行。比如 Oracle 支持数值范围 MySQL 不支持，Oracle 的 DATE 类型支持公元前的年份而 MySQL 的 datetime 只能为公元后的年份等等。遇到这些情况，DTLE 的默认行为是报错并且停止同步。

如果需要跳过这种阻塞情况，可以修改 DTLE 的环境变量然后重新启动 DTLE 服务。

shell> vi /etc/systemd/system/multi-user.target.wants/dtle-nomad.service
# 添加
[Service]
Environment="SkipErr=true"

shell> systemctl daemon-reload
shell> systemctl restart dtle-nomad

如果在使用 DTLE 时发现了任何问题，请及时联系我们。

DTLE repo： https://github.com/actiontech/dtle

DTLE docs： https://actiontech.github.io/dtle-docs-cn/

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