MySQL binlog記錄的所有操作實際上都有對應的事件類型的,譬如STATEMENT格式中的DML操作對應的是QUERY_EVENT類型,ROW格式下的DML操作對應的是ROWS_EVENT類型。 首先,看看源碼中定義的事件類型 源碼位置:mysql-5.7.14/libbinlogevents ...
MySQL binlog記錄的所有操作實際上都有對應的事件類型的,譬如STATEMENT格式中的DML操作對應的是QUERY_EVENT類型,ROW格式下的DML操作對應的是ROWS_EVENT類型。
首先,看看源碼中定義的事件類型
源碼位置:mysql-5.7.14/libbinlogevents/include/binlog_event.h
enum Log_event_type { /** Every time you update this enum (when you add a type), you have to fix Format_description_event::Format_description_event(). */ UNKNOWN_EVENT= 0, START_EVENT_V3= 1, QUERY_EVENT= 2, STOP_EVENT= 3, ROTATE_EVENT= 4, INTVAR_EVENT= 5, LOAD_EVENT= 6, SLAVE_EVENT= 7, CREATE_FILE_EVENT= 8, APPEND_BLOCK_EVENT= 9, EXEC_LOAD_EVENT= 10, DELETE_FILE_EVENT= 11, /** NEW_LOAD_EVENT is like LOAD_EVENT except that it has a longer sql_ex, allowing multibyte TERMINATED BY etc; both types share the same class (Load_event) */ NEW_LOAD_EVENT= 12, RAND_EVENT= 13, USER_VAR_EVENT= 14, FORMAT_DESCRIPTION_EVENT= 15, XID_EVENT= 16, BEGIN_LOAD_QUERY_EVENT= 17, EXECUTE_LOAD_QUERY_EVENT= 18, TABLE_MAP_EVENT = 19, /** The PRE_GA event numbers were used for 5.1.0 to 5.1.15 and are therefore obsolete. */ PRE_GA_WRITE_ROWS_EVENT = 20, PRE_GA_UPDATE_ROWS_EVENT = 21, PRE_GA_DELETE_ROWS_EVENT = 22, /** The V1 event numbers are used from 5.1.16 until mysql-trunk-xx */ WRITE_ROWS_EVENT_V1 = 23, UPDATE_ROWS_EVENT_V1 = 24, DELETE_ROWS_EVENT_V1 = 25, /** Something out of the ordinary happened on the master */ INCIDENT_EVENT= 26, /** Heartbeat event to be send by master at its idle time to ensure master's online status to slave */ HEARTBEAT_LOG_EVENT= 27, /** In some situations, it is necessary to send over ignorable data to the slave: data that a slave can handle in case there is code for handling it, but which can be ignored if it is not recognized. */ IGNORABLE_LOG_EVENT= 28, ROWS_QUERY_LOG_EVENT= 29, /** Version 2 of the Row events */ WRITE_ROWS_EVENT = 30, UPDATE_ROWS_EVENT = 31, DELETE_ROWS_EVENT = 32, GTID_LOG_EVENT= 33, ANONYMOUS_GTID_LOG_EVENT= 34, PREVIOUS_GTIDS_LOG_EVENT= 35, TRANSACTION_CONTEXT_EVENT= 36, VIEW_CHANGE_EVENT= 37, /* Prepared XA transaction terminal event similar to Xid */ XA_PREPARE_LOG_EVENT= 38, /** Add new events here - right above this comment! Existing events (except ENUM_END_EVENT) should never change their numbers */ ENUM_END_EVENT /* end marker */ };
實際上還是蠻多的,下麵就挑幾個重點的說一下
QUERY_EVENT
QUERY_EVENT以文本的形式來記錄事務的操作。
QUERY_EVENT類型的事件通常在以下幾種情況下使用:
1. 事務開始時,執行的BEGIN操作。
2. STATEMENT格式中的DML操作
3. ROW格式中的DDL操作
譬如:
mysql> show binlog events in 'mysql-bin.000021'; +------------------+-----+-------------+-----------+-------------+-----------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+-----------------------------------------------+ | mysql-bin.000021 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000021 | 120 | Query | 1 | 195 | BEGIN | | mysql-bin.000021 | 195 | Query | 1 | 298 | insert into test.t1 values(1,'a') | | mysql-bin.000021 | 298 | Xid | 1 | 329 | COMMIT /* xid=25 */ | | mysql-bin.000021 | 329 | Query | 1 | 408 | BEGIN | | mysql-bin.000021 | 408 | Query | 1 | 515 | use `test`; insert into test.t1 values(2,'b') | | mysql-bin.000021 | 515 | Xid | 1 | 546 | COMMIT /* xid=33 */ | +------------------+-----+-------------+-----------+-------------+-----------------------------------------------+
FORMAT_DESCRIPTION_EVENT
FORMAT_DESCRIPTION_EVENT是binlog version 4中為了取代之前版本中的START_EVENT_V3事件而引入的。它是binlog文件中的第一個事件,而且,該事件只會在binlog中出現一次。MySQL根據FORMAT_DESCRIPTION_EVENT的定義來解析其它事件。
它通常指定了MySQL Server的版本,binlog的版本,該binlog文件的創建時間。
譬如:
# at 4 #160817 11:00:10 server id 1 end_log_pos 120 CRC32 0x03010da1 Start: binlog v 4, server v 5.6.31-log created 160817 11:00:10 # Warning: this binlog is either in use or was not closed properly.
mysql> show binlog events in 'mysql-bin.000021'; +------------------+-----+-------------+-----------+-------------+-----------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+-----------------------------------------------+ | mysql-bin.000021 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | ...
ROWS_EVENT
對於ROW格式的binlog,所有的DML語句都是記錄在ROWS_EVENT中。
ROWS_EVENT分為三種:WRITE_ROWS_EVENT,UPDATE_ROWS_EVENT,DELETE_ROWS_EVENT,分別對應insert,update和delete操作。
對於insert操作,WRITE_ROWS_EVENT包含了要插入的數據
對於update操作,UPDATE_ROWS_EVENT不僅包含了修改後的數據,還包含了修改前的值。
對於delete操作,僅僅需要指定刪除的主鍵(在沒有主鍵的情況下,會給定所有列)
對於QUERY_EVENT事件,是以文本形式記錄DML操作的。而對於ROWS_EVENT事件,並不是文本形式,所以在通過mysqlbinlog查看基於ROW格式的binlog時,需要指定-vv --base64-output=decode-rows。
譬如:
mysql> show binlog events in 'mysql-bin.000027'; +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | mysql-bin.000027 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000027 | 120 | Query | 1 | 188 | BEGIN | | mysql-bin.000027 | 188 | Table_map | 1 | 236 | table_id: 80 (test.t1) | | mysql-bin.000027 | 236 | Write_rows | 1 | 278 | table_id: 80 flags: STMT_END_F | | mysql-bin.000027 | 278 | Xid | 1 | 309 | COMMIT /* xid=198 */ | | mysql-bin.000027 | 309 | Query | 1 | 377 | BEGIN | | mysql-bin.000027 | 377 | Table_map | 1 | 425 | table_id: 80 (test.t1) | | mysql-bin.000027 | 425 | Update_rows | 1 | 475 | table_id: 80 flags: STMT_END_F | | mysql-bin.000027 | 475 | Xid | 1 | 506 | COMMIT /* xid=199 */ | | mysql-bin.000027 | 506 | Query | 1 | 574 | BEGIN | | mysql-bin.000027 | 574 | Table_map | 1 | 622 | table_id: 80 (test.t1) | | mysql-bin.000027 | 622 | Delete_rows | 1 | 664 | table_id: 80 flags: STMT_END_F | | mysql-bin.000027 | 664 | Xid | 1 | 695 | COMMIT /* xid=200 */ | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ 13 rows in set (0.00 sec)
XID_EVENT
在事務提交時,不管是STATEMENT還是ROW格式的binlog,都會在末尾添加一個XID_EVENT事件代表事務的結束。該事件記錄了該事務的ID,在MySQL進行崩潰恢復時,根據事務在binlog中的提交情況來決定是否提交存儲引擎中狀態為prepared的事務。
ROTATE_EVENT
當binlog文件的大小達到max_binlog_size的值或者執行flush logs命令時,binlog會發生切換,這個時候會在當前的binlog日誌添加一個ROTATE_EVENT事件,用於指定下一個日誌的名稱和位置。
mysql> show binlog events in 'mysql-bin.000028'; +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | mysql-bin.000028 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000028 | 120 | Rotate | 1 | 167 | mysql-bin.000029;pos=4 | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ 2 rows in set (0.00 sec)
# at 120 #160817 12:34:26 server id 1 end_log_pos 167 CRC32 0xd965567c Rotate to mysql-bin.000029 pos: 4
GTID_LOG_EVENT
在啟用GTID模式後,MySQL實際上為每個事務都分配了個GTID
譬如:
# at 448 #160818 5:37:32 server id 1 end_log_pos 496 CRC32 0xaeb24aac GTID [commit=yes] SET @@SESSION.GTID_NEXT= 'cad449f2-5d4f-11e6-b353-000c29c64704:3'/*!*/;
# at 496 #160818 5:37:32 server id 1 end_log_pos 571 CRC32 0x042ca092 Query thread_id=2 exec_time=0 error_code=0 SET TIMESTAMP=1471469852/*!*/; BEGIN /*!*/;
# at 571 #160818 5:37:32 server id 1 end_log_pos 674 CRC32 0xa35beb37 Query thread_id=2 exec_time=0 error_code=0 SET TIMESTAMP=1471469852/*!*/; insert into test.t1 values(2,'b') /*!*/;
# at 674 #160818 5:37:32 server id 1 end_log_pos 705 CRC32 0x1905d8c6 Xid = 12 COMMIT/*!*/;
mysql> show binlog events in 'mysql-bin.000033'; +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ | mysql-bin.000033 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000033 | 120 | Previous_gtids | 1 | 191 | cad449f2-5d4f-11e6-b353-000c29c64704:1 | | mysql-bin.000033 | 191 | Gtid | 1 | 239 | SET @@SESSION.GTID_NEXT= 'cad449f2-5d4f-11e6-b353-000c29c64704:2' | | mysql-bin.000033 | 239 | Query | 1 | 314 | BEGIN | | mysql-bin.000033 | 314 | Query | 1 | 417 | insert into test.t1 values(1,'a') | | mysql-bin.000033 | 417 | Xid | 1 | 448 | COMMIT /* xid=11 */ | | mysql-bin.000033 | 448 | Gtid | 1 | 496 | SET @@SESSION.GTID_NEXT= 'cad449f2-5d4f-11e6-b353-000c29c64704:3' | | mysql-bin.000033 | 496 | Query | 1 | 571 | BEGIN | | mysql-bin.000033 | 571 | Query | 1 | 674 | insert into test.t1 values(2,'b') | | mysql-bin.000033 | 674 | Xid | 1 | 705 | COMMIT /* xid=12 */ | | mysql-bin.000033 | 705 | Rotate | 1 | 752 | mysql-bin.000034;pos=4 | +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ 11 rows in set (0.00 sec)
PREVIOUS_GTIDS_LOG_EVENT
開啟GTID模式後,每個binlog開頭都會有一個PREVIOUS_GTIDS_LOG_EVENT事件,它的值是上一個binlog的PREVIOUS_GTIDS_LOG_EVENT+GTID_LOG_EVENT,實際上,在資料庫重啟的時候,需要重新填充gtid_executed的值,該值即是最新一個binlog的PREVIOUS_GTIDS_LOG_EVENT+GTID_LOG_EVENT。
譬如:
mysql> show binlog events in 'mysql-bin.000033'; +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ | mysql-bin.000033 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000033 | 120 | Previous_gtids | 1 | 191 | cad449f2-5d4f-11e6-b353-000c29c64704:1 | | mysql-bin.000033 | 191 | Gtid | 1 | 239 | SET @@SESSION.GTID_NEXT= 'cad449f2-5d4f-11e6-b353-000c29c64704:2' | | mysql-bin.000033 | 239 | Query | 1 | 314 | BEGIN | | mysql-bin.000033 | 314 | Query | 1 | 417 | insert into test.t1 values(1,'a') | | mysql-bin.000033 | 417 | Xid | 1 | 448 | COMMIT /* xid=11 */ | | mysql-bin.000033 | 448 | Gtid | 1 | 496 | SET @@SESSION.GTID_NEXT= 'cad449f2-5d4f-11e6-b353-000c29c64704:3' | | mysql-bin.000033 | 496 | Query | 1 | 571 | BEGIN | | mysql-bin.000033 | 571 | Query | 1 | 674 | insert into test.t1 values(2,'b') | | mysql-bin.000033 | 674 | Xid | 1 | 705 | COMMIT /* xid=12 */ | | mysql-bin.000033 | 705 | Rotate | 1 | 752 | mysql-bin.000034;pos=4 | +------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+ 11 rows in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000034'; +------------------+-----+----------------+-----------+-------------+------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+----------------+-----------+-------------+------------------------------------------+ | mysql-bin.000034 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.31-log, Binlog ver: 4 | | mysql-bin.000034 | 120 | Previous_gtids | 1 | 191 | cad449f2-5d4f-11e6-b353-000c29c64704:1-3 | +------------------+-----+----------------+-----------+-------------+------------------------------------------+ 2 rows in set (0.00 sec)
mysql-bin.000033日誌中的Previous_gtids是cad449f2-5d4f-11e6-b353-000c29c64704:1,GTID是cad449f2-5d4f-11e6-b353-000c29c64704:2和cad449f2-5d4f-11e6-b353-000c29c64704:3,這樣,在下一個日誌,即mysql-bin.000034中的Previous_gtids是cad449f2-5d4f-11e6-b353-000c29c64704:1-3。
# at 120 #160818 5:39:38 server id 1 end_log_pos 191 CRC32 0x4e84f3b5 Previous-GTIDs # cad449f2-5d4f-11e6-b353-000c29c64704:1-3
STOP_EVENT
當MySQL資料庫停止時,會在當前的binlog末尾添加一個STOP_EVENT事件表示資料庫停止。
譬