利用MyFlash闪回丢失数据

 

    MyFlash is an open source tool released by Meituan-Dianping which can be used to flashback MySQL DML data.here's the github link: https://github.com/Meituan-Dianping/MyFlash

    after downloaded the tool and extracted the zip package,i got this structure:

 

 [root@zlm1 :: /vagrant/MyFlash-master]
 #ls -l
 total
 drwxrwxrwx  vagrant vagrant  Jun  : binary
 -rwxrwxrwx  vagrant vagrant  Oct   build.sh
 drwxrwxrwx  vagrant vagrant  Jun  : doc
 -rwxrwxrwx  vagrant vagrant  Oct   License.md
 -rwxrwxrwx  vagrant vagrant  Oct   README.md
 drwxrwxrwx  vagrant vagrant  Jun  : source
 drwxrwxrwx  vagrant vagrant  Jun  : testbinlog

    the official document recommend to install the tool by dynamic compliling link way to install,but i prefer to use the binary way instead.let's see the parameter and usage of the command:

 

 [root@zlm1 :: /vagrant/MyFlash-master/binary]
 #./flashback --help
 Usage:
   flashback [OPTION...]
 Help Options:
   -h, --help Show help options
 Application Options:
   --databaseNames databaseName to apply. if multiple, seperate by comma(,)
   --tableNames tableName to apply. if multiple, seperate by comma(,)
   --start-position start position
   --stop-position stop position
   --start-datetime start time (format %Y-%m-%d %H:%M:%S)
   --stop-datetime stop time (format %Y-%m-%d %H:%M:%S)
   --sqlTypes sql type to filter . support INSERT, UPDATE ,DELETE. if multiple, seperate by comma(,)
   --maxSplitSize max file size after split, the uint is M
   --binlogFileNames binlog files to process. if multiple, seperate by comma(,)
   --outBinlogFileNameBase output binlog file name base
   --logLevel log level, available option is debug,warning,error
   --include-gtids gtids to process
   --exclude-gtids gtids to skip

 

    first of all,create the test environment as below:

 

 root@localhost:mysql3306.sock [zlm]::>create table test_flashbk(
     -> id bigint not null auto_increment,
     -> name varchar() not null default '',
     -> primary key(id)
     -> ) engine=innodb default charset=utf8mb4;
 Query OK,  rows affected (0.04 sec)

 root@localhost:mysql3306.sock [zlm]::>delimiter //
 root@localhost:mysql3306.sock [zlm]::>create procedure pro_flashbk()
     -> begin
     -> declare id int;
     -> set id = ;
     -> while id> do
     -> insert into test_flashbk(name) values ('aaron8219');
     -> set id=id-;
     -> end while;
     -> end //
 Query OK,  rows affected (0.04 sec)

 root@localhost:mysql3306.sock [zlm]::>delimiter ;
 root@localhost:mysql3306.sock [zlm]::>call pro_flashbk();
 Query OK,  row affected (11.06 sec)

 root@localhost:mysql3306.sock [zlm]::>select count(*) from test_flashbk;
 +----------+
 | count(*) |
 +----------+
 |    |
 +----------+
  row in set (0.02 sec)

 root@localhost:mysql3306.sock [zlm]::>select id,name from test_flashbk limit ,;
 +----+-----------+
 | id | name      |
 +----+-----------+
 |   | aaron8219 |
 |   | aaron8219 |
 |   | aaron8219 |
 |   | aaron8219 |
 |   | aaron8219 |
 +----+-----------+
  rows in set (0.00 sec)

 root@localhost:mysql3306.sock [zlm]::>select @@autocommit;
 +--------------+
 | @@autocommit |
 +--------------+
 |             |
 +--------------+
  row in set (0.03 sec)

 root@localhost:mysql3306.sock [zlm]::>

    secondly,let's mimic the situation about updating records without using "where clause",after that

the operation will update all the records in the test table "test_flashbk":

 

 root@localhost:mysql3306.sock [zlm]::>update test_flashbk set name='zlm';
 Query OK,  rows affected (2.29 sec)
 Rows matched:   Changed:   Warnings: 

 root@localhost:mysql3306.sock [zlm]::>select id,name from test_flashbk limit ,;
 +----+------+
 | id | name |
 +----+------+
 |   | zlm  |
 |   | zlm  |
 |   | zlm  |
 |   | zlm  |
 |   | zlm  |
 +----+------+
  rows in set (0.00 sec)

 root@localhost:mysql3306.sock [zlm]::>show binary logs;
 +------------------+-----------+
 | Log_name         | File_size |
 +------------------+-----------+
 | mysql-bin. |        |
 | mysql-bin. |       |
 | mysql-bin. |        |
 | mysql-bin. |        |
 | mysql-bin. |  |
 | mysql-bin. |   |
 +------------------+-----------+
  rows in set (0.04 sec)

 root@localhost:mysql3306.sock [zlm]::>exit
 Bye

 [root@zlm1 :: ~]
 #cd /data/mysql/mysql3306/logs

 [root@zlm1 :: /data/mysql/mysql3306/logs]
 #ls -l
 total
 -rw-r-----  mysql mysql        May  : mysql-bin.
 -rw-r-----  mysql mysql       May  : mysql-bin.
 -rw-r-----  mysql mysql        May  : mysql-bin.
 -rw-r-----  mysql mysql        May  : mysql-bin.
 -rw-r-----  mysql mysql  Jun   : mysql-bin.
 -rw-r-----  mysql mysql   Jun   : mysql-bin.
 -rw-r-----  mysql mysql        Jun   : mysql-bin.index

 [root@zlm1 :: /data/mysql/mysql3306/logs]
 #

    now,let's using the MyFlash tool to flashback the correct data.you should notice that only one binary log can be put in the parameter "binlogFileNames".it cannot be too big up to 256M,'cauze in my early case,i put 100w records into the test table at the begining,the operation was killed by OS automatically twice,it's amazing...sometime i'll test it again to find out the real reason for that.

 

 [root@zlm1 :: ~]
 #cd /vagrant/MyFlash-master/binary/

 [root@zlm1 :: /vagrant/MyFlash-master/binary]
 #ls -l
 total
 -rwxrwxrwx  vagrant vagrant    Oct    flashback
 -rwxrwxrwx  vagrant vagrant  Oct    mysqlbinlog20160408

 [root@zlm1 :: /vagrant/MyFlash-master/binary]
 #./flashback --databaseNames zlm --tableNames test_flashbk --sqlTypes update  --maxSplitSize= --binlogFileNames=/data/mysql/mysql3306/logs/mysql-bin.

 [root@zlm1 :: /vagrant/MyFlash-master/binary]
 #ls -l
 total
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant  Jun   : binlog_output_base.
 -rwxrwxrwx  vagrant vagrant     Oct    flashback
 -rwxrwxrwx  vagrant vagrant   Oct    mysqlbinlog20160408

 [root@zlm1 :: /vagrant/MyFlash-master/binary]
 #

    here,i used the parameter "maxSplitSize" to split the output flashback file into 7 files，each one became 10M around.after that,i try to recover the data by the shell script below,unfortunately it failed:

 

 [root@zlm1 :: ~]
 #cat > recover.sh <<aaron8219
 > #!/bin/bash
 > BASEDIR=/vagrant/MyFlash-master/binary
 > FILE=\`find \${BASEDIR} -name "binlog_output_base.00000*"|sort -n\`
 > for i in \${FILE}
 > do
 >   mysqlbinlog \${i} | mysql
 > done
 > aaron8219

 [root@zlm1 :: ~]
 #cat recover.sh
 #!/bin/bash
 BASEDIR=/vagrant/MyFlash-master/binary
 FILE=`find ${BASEDIR} -name "binlog_output_base.00000*"|sort -n`
 for i in ${FILE}
 do
   mysqlbinlog ${i} | mysql
 done

 [root@zlm1 :: ~]
 #ls -l
 total
 -rw-------.  root root  Jul    anaconda-ks.cfg
 -rwxr-xr-x   root root    Apr   : mysqld.sh
 -rwxr-xr-x   root root    Jun   : mysql.sh
 -rw-r--r--   root root   Jun   : recover.sh
 -rw-r--r--   root root     May  : rename_tb.sql

 [root@zlm1 :: ~]
 #sh recover.sh
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.
 ERROR  (HY000) at line : @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.

---

https://bugs.mysql.com/bug.php?id=85480

this website reported the bug on 5.7.17,but mine is 5.7.21

Bug #85480	@@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON
Submitted:	16 Mar 2017 12:01	Modified:	26 Mar 2017 19:04
Reporter:	kfpanda kf	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S3 (Non-critical)
Version:	5.7.17	OS:	Any
Assigned to:		CPU Architecture:	Any

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[16 Mar 2017 12:01] kfpanda kf

Description:
mysqlbinlog printed a ROLLBACK at the end of the binary log
    file, which when played back caused the error
    -@@SESSION.GTID_NEXT cannot be set to ANONYMOUS when
    @@GLOBAL.GTID_MODE = ON..- This occurred when the binary log file
    did not include any data related events.

How to repeat:

Generate a binary log file which did not include any data related events.

mysql -uroot -p123456

mysql> show binary logs;
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000001 |       177 |
| mysql-bin.000002 |       201 |
+------------------+-----------+
mysql> flush logs;
mysql> flush logs;
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000001 |       177 |
| mysql-bin.000002 |       201 |
| mysql-bin.000003 |       201 |
| mysql-bin.000004 |       201 |
+------------------+-----------+

#  mysqlbinlog mysql-bin.000003|mysql -uroot -p'123456'
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1782 (HY000) at line 19: @@SESSION.GTID_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON.

Suggested fix:
stops a ROLLBACK from setting gtid_next to ANONYMOUS when gtid_next has not yet been determined by a subsequent event.

---

 root@localhost:mysql3306.sock [(none)]::>select @@global.gtid_next;
 ERROR  (HY000): Variable 'gtid_next' is a SESSION variable
 root@localhost:mysql3306.sock [(none)]::>select @@gtid_next;
 +-------------+
 | @@gtid_next |
 +-------------+
 | AUTOMATIC   |
 +-------------+
  row in set (0.00 sec)

 root@localhost:mysql3306.sock [(none)]::>

 

    it seems not the bug issue.on the other hand,the description about GTID_MODE in official document was described as below:

 

---

GTID

The GTID column contains the value of gtid_next, which can be one of ANONYMOUS, AUTOMATIC, or a GTID using the formatUUID:NUMBER. For transactions that use gtid_next=AUTOMATIC, which is all normal client transactions, the GTID column changes when the transaction commits and the actual GTID is assigned. If gtid_mode is either ON or ON_PERMISSIVE, the GTID column changes to the transaction's GTID. If gtid_mode is either OFF or OFF_PERMISSIVE, the GTID column changes to ANONYMOUS.

来源： https://dev.mysql.com/doc/refman/5.7/en/events-transactions-current-table.html

---

    now i try to set  gtid_mode=off_permissive step by step:

 

 [root@zlm1 :: ~]
 #mysql
 Welcome to the MySQL monitor.  Commands end with ; or \g.
 Your MySQL connection id is
 Server version: 5.7.-log MySQL Community Server (GPL)

 Copyright (c) , , 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.

 root@localhost:mysql3306.sock [(none)]::>select @@global.gtid_mode;
 +--------------------+
 | @@global.gtid_mode |
 +--------------------+
 | ON                 |
 +--------------------+
  row in set (0.00 sec)

 root@localhost:mysql3306.sock [(none)]::>set @@global.gtid_mode=off_permissive;
 ERROR  (HY000): The value of @@GLOBAL.GTID_MODE can only be changed one step at a time: OFF <-> OFF_PERMISSIVE <-> ON_PERMISSIVE <-> ON. Also note that this value must be stepped up or down simultaneously on all servers. See the Manual for instructions.
 root@localhost:mysql3306.sock [(none)]::>select @@global.gtid_mode;
 +--------------------+
 | @@global.gtid_mode |
 +--------------------+
 | ON_PERMISSIVE      |
 +--------------------+
  row in set (0.00 sec)

 root@localhost:mysql3306.sock [(none)]::>set @@global.gtid_mode=off_permissive;
 Query OK,  rows affected (0.01 sec)

 root@localhost:mysql3306.sock [(none)]::>select @@global.gtid_mode;
 +--------------------+
 | @@global.gtid_mode |
 +--------------------+
 | OFF_PERMISSIVE     |
 +--------------------+
  row in set (0.00 sec)

 root@localhost:mysql3306.sock [(none)]::>exit

 Bye

    it failed again with ERROR 1032，cant't find record in table:

 

 [root@zlm1 :: ~]
 #sh recover.sh 

 ERROR  (HY000) at line : Can't find record in 'test_flashbk'
 ERROR  (HY000) at line : Can't find record in 'test_flashbk'
 ERROR  (HY000) at line : Can't find record in 'test_flashbk'

    then i modify the shell script file add "--skip-gtids" but it still not work normally,this time,i even got the ERROR 1062 excepts the ERROR 1032:

 [root@zlm1 :: ~]
 #vi recover.sh 

 [root@zlm1 :: ~]
 #cat recover.sh
 #!/bin/bash
 BASEDIR=/vagrant/MyFlash-master/binary
 FILE=`find ${BASEDIR} -name "binlog_output_base.00000*"|sort -n`
 for i in ${FILE}
 do
   mysqlbinlog --skip-gtids ${i} | mysql
 done

 [root@zlm1 :: ~]
 #sh recover.sh
 ERROR  (HY000) at line : Can't find record in 'test_flashbk'
 ERROR  (HY000) at line : Can't find record in 'test_flashbk'
 ERROR  (HY000) at line : Can't find record in 'test_flashbk'
 ERROR  () at line : Duplicate entry '' for key 'PRIMARY'
 ERROR  () at line : Duplicate entry '' for key 'PRIMARY'
 ERROR  () at line : Duplicate entry '' for key 'PRIMARY'

 [root@zlm1 :: ~]
 #

    now,i have no idea about how to solve the issue.it seems not so convenient to flashback the incorrect data back to the original state with the MyFlash tool,it still has some defect,restriction and so forth,hope it will be enhensed in the future release.