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==== Description ====
Flashback can rollback the instances/databases/tables to an old snapshot.
It's implement on Server-Level by full image format binary logs (--binlog-row-image=FULL), so it supports all engines.
Currently, it’s a feature inside mysqlbinlog tool (with --flashback arguments).
Because the flashback binlog events will store in the memory, you should check if there is enough memory in your machine.
==== New Arguments to mysqlbinlog ====
--flashback (-B)
It will let mysqlbinlog to work on FLASHBACK mode.
==== New Arguments to mysqld ====
--flashback
Setup the server to use flashback. This enables binary log in row mode
and will enable extra logging for DDL's needed by flashback feature
==== Example ====
I have a table "t" in database "test", we can compare the output with "--flashback" and without.
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" > /tmp/1.sql
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" -B > /tmp/2.sql
Then, importing the output flashback file (/tmp/2.log), it can flashback your database/table to the special time (--start-datetime).
And if you know the exact postion, "--start-postion" is also works, mysqlbinlog will output the flashback logs that can flashback to "--start-postion" position.
==== Implement ====
1. As we know, if binlog_format is ROW (binlog-row-image=FULL in 10.1 and later), all columns value are store in the row event, so we can get the data before mis-operation.
2. Just do following things:
2.1 Change Event Type, INSERT->DELETE, DELETE->INSERT.
For example:
INSERT INTO t VALUES (...) ---> DELETE FROM t WHERE ...
DELETE FROM t ... ---> INSERT INTO t VALUES (...)
2.2 For Update_Event, swapping the SET part and WHERE part.
For example:
UPDATE t SET cols1 = vals1 WHERE cols2 = vals2
--->
UPDATE t SET cols2 = vals2 WHERE cols1 = vals1
2.3 For Multi-Rows Event, reverse the rows sequence, from the last row to the first row.
For example:
DELETE FROM t WHERE id=1; DELETE FROM t WHERE id=2; ...; DELETE FROM t WHERE id=n;
--->
DELETE FROM t WHERE id=n; ...; DELETE FROM t WHERE id=2; DELETE FROM t WHERE id=1;
2.4 Output those events from the last one to the first one which mis-operation happened.
For example:
164 lines
4.3 KiB
Plaintext
164 lines
4.3 KiB
Plaintext
--source include/have_log_bin.inc
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--source include/have_innodb.inc
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--echo #
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--echo # Preparatory cleanup.
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--echo #
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--disable_warnings
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DROP TABLE IF EXISTS t1;
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--enable_warnings
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--echo #
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--echo # We need a fixed timestamp to avoid varying results.
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--echo #
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SET timestamp=1000000000;
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--echo #
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--echo # Delete all existing binary logs.
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--echo #
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RESET MASTER;
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CREATE TABLE t1 (
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c01 tinyint,
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c02 smallint,
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c03 mediumint,
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c04 int,
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c05 bigint,
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c06 char(10),
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c07 varchar(20),
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c08 TEXT
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) ENGINE=InnoDB;
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--echo #
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--echo # Insert data to t1
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--echo #
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INSERT INTO t1 VALUES(0,0,0,0,0,'','','');
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INSERT INTO t1 VALUES(1,2,3,4,5, "abc", "abcdefg", "abcedfghijklmnopqrstuvwxyz");
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INSERT INTO t1 VALUES(127, 32767, 8388607, 2147483647, 9223372036854775807, repeat('a', 10), repeat('a', 20), repeat('a', 255));
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--echo #
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--echo # Update t1
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--echo #
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UPDATE t1 SET c01=100 WHERE c02=0 OR c03=3;
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--echo #
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--echo # Clear t1
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--echo #
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DELETE FROM t1;
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FLUSH LOGS;
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--echo #
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--echo # Show mysqlbinlog result without -B
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--echo #
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let $MYSQLD_DATADIR= `select @@datadir`;
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--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
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--replace_regex /SQL_LOAD_MB-[0-9]-[0-9]/SQL_LOAD_MB-#-#/ /exec_time=[0-9]*/exec_time=#/ /end_log_pos [0-9]*/end_log_pos #/ /# at [0-9]*/# at #/ /Xid = [0-9]*/Xid = #/ /thread_id=[0-9]*/thread_id=#/ /table id [0-9]*/table id #/ /mapped to number [0-9]*/mapped to number #/ /server v [^ ]*/server v #.##.##/ /CRC32 0x[0-9a-f]*/CRC32 XXX/
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--exec $MYSQL_BINLOG --base64-output=decode-rows -v -v $MYSQLD_DATADIR/master-bin.000001
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--echo #
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--echo # Show mysqlbinlog result with -B
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--echo #
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let $MYSQLD_DATADIR= `select @@datadir`;
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--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
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--replace_regex /SQL_LOAD_MB-[0-9]-[0-9]/SQL_LOAD_MB-#-#/ /exec_time=[0-9]*/exec_time=#/ /end_log_pos [0-9]*/end_log_pos #/ /# at [0-9]*/# at #/ /Xid = [0-9]*/Xid = #/ /thread_id=[0-9]*/thread_id=#/ /table id [0-9]*/table id #/ /mapped to number [0-9]*/mapped to number #/ /server v [^ ]*/server v #.##.##/ /CRC32 0x[0-9a-f]*/CRC32 XXX/
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--exec $MYSQL_BINLOG -B --base64-output=decode-rows -v -v $MYSQLD_DATADIR/master-bin.000001
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--echo #
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--echo # Insert data to t1
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--echo #
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TRUNCATE TABLE t1;
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INSERT INTO t1 VALUES(0,0,0,0,0,'','','');
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INSERT INTO t1 VALUES(1,2,3,4,5, "abc", "abcdefg", "abcedfghijklmnopqrstuvwxyz");
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INSERT INTO t1 VALUES(127, 32767, 8388607, 2147483647, 9223372036854775807, repeat('a', 10), repeat('a', 20), repeat('a', 60));
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--echo #
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--echo # Delete all existing binary logs.
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--echo #
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RESET MASTER;
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SELECT * FROM t1;
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--echo #
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--echo # Operate some data
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--echo #
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UPDATE t1 SET c01=20;
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UPDATE t1 SET c02=200;
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UPDATE t1 SET c03=2000;
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DELETE FROM t1;
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FLUSH LOGS;
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--echo #
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--echo # Flashback & Check the result
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--echo #
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let $MYSQLD_DATADIR= `select @@datadir`;
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--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
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--exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_1.sql
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--exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_1.sql;"
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SELECT * FROM t1;
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RESET MASTER;
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--echo #
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--echo # UPDATE multi-rows in one event
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--echo #
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BEGIN;
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UPDATE t1 SET c01=10 WHERE c01=0;
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UPDATE t1 SET c01=20 WHERE c01=10;
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COMMIT;
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FLUSH LOGS;
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--echo #
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--echo # Flashback & Check the result
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--echo #
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let $MYSQLD_DATADIR= `select @@datadir`;
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--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
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--exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_2.sql
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--exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_2.sql;"
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SELECT * FROM t1;
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DROP TABLE t1;
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--echo #
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--echo # Self-referencing foreign keys
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--echo #
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CREATE TABLE t1 (a INT PRIMARY KEY, b INT, FOREIGN KEY my_fk(b) REFERENCES t1(a)) ENGINE=InnoDB;
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BEGIN;
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INSERT INTO t1 VALUES (1, NULL);
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INSERT INTO t1 VALUES (2, 1), (3, 2), (4, 3);
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COMMIT;
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SELECT * FROM t1;
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# New binlog
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RESET MASTER;
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DELETE FROM t1 ORDER BY a DESC;
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FLUSH LOGS;
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--echo #
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--echo # Flashback & Check the result
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--echo #
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let $MYSQLD_DATADIR= `select @@datadir`;
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--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
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--exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_3.sql
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--exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_3.sql;"
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SELECT * FROM t1;
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DROP TABLE t1;
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