前言:
經過前面文章學習,我們知道 binlog 會記錄數據庫所有執行的 DDL 和 DML 語句(除了數據查詢語句select、show等)。注意默認情況下會記錄所有庫的操作,那么如果我們有另類需求,比如說只讓某個庫記錄 binglog 或排除某個庫記錄 binlog ,是否支持此類需求呢?本篇文章我們一起來看下。
1. binlog_do_db 與 binlog_ignore_db
當數據庫實例開啟 binlog 時,我們執行 show master status 命令,會看到有 Binlog_Do_DB 與 Binlog_Ignore_DB 選項。
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000009 | 282838 | | | |
+---------------+----------+--------------+------------------+-------------------+
默認情況下,這兩個選項為空,那么這兩個參數有何作用?是否如同其字面意思一個只讓某個庫記錄 binglog 一個排除某個庫記錄 binlog 呢?筆者查閱官方文檔,簡單說明下這兩個參數的作用:
- binlog_do_db:此參數表示只記錄指定數據庫的二進制日志,默認全部記錄。
- binlog_ignore_db:此參數表示不記錄指定的數據庫的二進制日志。
這兩個參數為互斥關系,一般只選擇其一設置,只能在啟動命令行中或配置文件中加入。指定多個數據庫要分行寫入,舉例如下:
# 指定 db1 db2 記錄binlog
[mysqld]
binlog_do_db = db1
binlog_do_db = db2
# 不讓 db3 db4 記錄binlog
[mysqld]
binlog_ignore_db = db3
binlog_ignore_db = db4
此外,這二者參數具體作用與否還與 binlog 格式有關系,在某些情況下 binlog 格式設置為 STATEMENT 或 ROW 會有不同的效果。在實際應用中 binlog_ignore_db 用途更廣泛些,比如說某個庫的數據不太重要,為了減輕服務器寫入壓力,我們可能不讓該庫記錄 binlog 。網上也有文章說設置 binlog_ignore_db 會導致從庫同步錯誤,那么設置該參數到底有什么效果呢,下面我們來具體實驗下。
2. binlog_ignore_db 具體效果
首先說明下,我的測試數據庫實例是 5.7.23 社區版本,共有 testdb、logdb 兩個業務庫,我們設置 logdb 不記錄 binlog ,下面來具體實驗下:
# binlog 為 ROW 格式
# 1.不使用 use db
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 154 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
mysql> select database();
+------------+
| database() |
+------------+
| NULL |
+------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE testdb.`test_tb1` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.06 sec)
mysql> insert into testdb.test_tb1 values (1001,'sdfde');
Query OK, 1 row affected (0.01 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 653 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE logdb.`log_tb1` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql> insert into logdb.log_tb1 values (1001,'sdfde');
Query OK, 1 row affected (0.00 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 883 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
mysql> insert into logdb.log_tb1 values (1002,'sdsdfde');
Query OK, 1 row affected (0.01 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 883 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
mysql> alter table logdb.log_tb1 add column c3 varchar(20);
Query OK, 0 rows affected (0.12 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1070 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
# 結論:其他庫記錄正常 logdb庫會記錄DDL 不記錄DML
# 2.使用 use testdb跨庫
mysql> use testdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| testdb |
+------------+
1 row in set (0.00 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1070 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE `test_tb2` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql> insert into test_tb2 values (1001,'sdfde');
Query OK, 1 row affected (0.04 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1574 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE logdb.`log_tb2` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1810 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> insert into logdb.log_tb2 values (1001,'sdfde');
Query OK, 1 row affected (0.01 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1810 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
# 結論:同樣logdb庫會記錄DDL 不記錄DML
# 3.使用 use logdb跨庫
mysql> use logdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| logdb |
+------------+
1 row in set (0.00 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1810 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE testdb.`test_tb3` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.23 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 1810 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> insert into testdb.test_tb3 values (1001,'sdfde');
Query OK, 1 row affected (0.02 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2081 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE `log_tb3` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2081 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> insert into log_tb3 values (1001,'sdfde');
Query OK, 1 row affected (0.02 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2081 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
# 結論:logdb都不記錄 同時不記錄其他庫的DDL
# 4.每次操作都進入此庫 不跨庫
mysql> use testdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2081 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> CREATE TABLE `test_tb4` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql> insert into test_tb4 values (1001,'sdfde');
Query OK, 1 row affected (0.01 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2585 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> use logdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> CREATE TABLE `log_tb4` ( id int , name varchar(30) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.04 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2585 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> insert into log_tb4 values (1001,'sdfde');
Query OK, 1 row affected (0.01 sec)
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000011 | 2585 | | logdb | |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
# 結論:其他庫全部記錄 logdb全不記錄
同樣的,將 binlog 格式設置為 STATEMENT ,再次進行測試,這里不再贅述測試過程,總結下 STATEMENT 格式下的實驗結果:
- 未選擇任何數據庫進行操作,所有都會記錄。
- 選擇testdb,對testdb和logdb分別進行操作,所有庫都會記錄。
- 選擇logdb,對testdb和logdb分別進行操作,所有庫都不會記錄。
- 選擇某個庫并只對當前庫進行操作,則記錄正常,不會記錄logdb。
看了這么多實驗數據,你是否眼花繚亂了呢,下面我們以思維導圖的形式總結如下:

這么看來 binlog_ignore_db 參數的效果確實和諸多因素有關,特別是有從庫的情況下,主庫要特別小心使用此參數,很容易產生主從同步錯誤。不過,按照嚴格標準只對當前數據庫進行操作,則不會產生問題。這也告訴我們要嚴格按照標準來,只賦予業務賬號某個單庫的權限,也能避免各種問題發生。
總結:
不清楚各位讀者是否對這種介紹參數的文章感興趣呢?可能這些是數據庫運維人員比較關注的吧。本篇文章主要介紹關于 binlog 的 binlog_ignore_db 參數的具體作用,可能本篇文章實驗環境還不夠考慮周全,有興趣的同學可以參考下官方文檔,有助于對該參數有更深入的了解。
以上就是MySQL binlog參數的使用的詳細內容,更多關于MySQL binlog參數的資料請關注腳本之家其它相關文章!
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