一 爲什麼需要延時備份
在上一篇文章中,我們講到MySQL備份與恢復之percona-xtrabackup實現增量備份及恢復,percona-xtrabackup是一個優秀的用於增量備份的工具。今天我們講到的延時備份也是使用他們的產品。
以前在MySQL AB複製一文中提到了AB複製。我們首先回顧下MySQL複製的相關要點。AB複製又稱主從複製,實現的是數據同步。經過以下步驟:
1)主服務器把數據更改記錄到二進制日誌中,這個操作叫做二進制日誌事件;
2)從服務器把主服務器的二進制日誌事件拷貝到自己的中繼日誌(relay log)中;
3)從服務器執行中繼日誌中的事件,把更改應用到自己的數據上。
在生產中,我們在使用 mysql AB 複製技術不但可以起到數據庫層面負載均衡的能力,還可以起到備份數據的功能,但有的時候我們可能由於不小心誤操作導致數據被刪除,這這個時候 slave服務器上的數據也會同時被刪除,如果我們能夠能是的其中的一臺 slave 延時備份的話, 這樣就可以從 slave服務器上找回被誤刪的數據了。
從服務器到主服務器中拷貝二進制日誌文件,如果在併發量高,網絡延時嚴重的情況下,會對主服務器造成相當大的壓力,負載高,必定會出現很多問題,比如訪問延遲,IO瓶頸,網絡擁塞等等。服務器壓力過大是我們都不願看到的情況,那有沒有方案緩解這種情況呢?有,這就是本文講到的延時備份。延時備份通過第三方工具,將檢查同步和真正同步的時間控制在一定的範圍內,而不是主服務器數據發生變化,從服務器立即去同步二進制事件到自己的中繼日誌中,這樣的話可以大大減輕主服務器的壓力,並且基於AB複製的優點,可以達到備份數據的目的。
好了,看下延時備份的示意圖。
二 延時備份示意圖
三 延時備份模擬
網絡拓撲圖
實驗環境簡介
serv01:主服務器 192.168.1.11serv01.host.com
serv08:及時同步服務器 192.168.1.18serv08.host.com
serv09:延時同步服務器 192.168.1.19serv09.host.com
操作系統版本
RHEL Server6.1 64位系統
使用到的軟件包版本
mysql-5.5.29-linux2.6-x86_64.tar.gz
percona-toolkit-2.1.7-1.noarch.rpm
第一步,搭建環境。修改配置文件,注意每臺的server-id不一致;
[root@serv01 ~]# cat /etc/my.cnf | grep server-id server-id = 1 #server-id = 2 [root@serv01 ~]# /etc/init.d/mysqld start Starting MySQL SUCCESS! [root@serv08 ~]# cat /etc/my.cnf | grep server-id server-id = 2 #server-id = 2 [root@serv08 ~]# /etc/init.d/mysqld start Starting MySQL SUCCESS! [root@serv09 ~]# cat /etc/my.cnf | grep server-id server-id = 3 #server-id = 2 [root@serv09 ~]# /etc/init.d/mysqld start Starting MySQL SUCCESS!
第二步,serv01serv08 serv09清空日誌
serv01 mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 683 | +------------------+-----------+ 1 row in set (0.01 sec) mysql> reset master; Query OK, 0 rows affected (0.01 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 107 | +------------------+-----------+ 1 row in set (0.00 sec) serv08 mysql> reset master; Query OK, 0 rows affected (0.02 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 107 | +------------------+-----------+ 1 row in set (0.00 sec) serv09 mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 107 | +------------------+-----------+ 1 row in set (0.00 sec) mysql> reset master; Query OK, 0 rows affected (0.00 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 107 | +------------------+-----------+ 1 row in set (0.00 sec)
第三步,主服務器serv01創建授權用戶
mysql> grant replication client, replication slave on *.* to 'larry'@'192.168.1.%' identified by 'larry';
第四步,serv08修改master設置,開啓slave,查看slave狀態
mysql> change master to -> master_host='192.168.1.11', -> master_user='larry', -> master_password='larry', -> master_port=3306, -> master_log_file='mysql-bin.000001', -> master_log_pos=107; Query OK, 0 rows affected (0.03 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec) mysql> show slave status \G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.11 Master_User: larry Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000001 Read_Master_Log_Pos: 107 Relay_Log_File: serv08-relay-bin.000002 Relay_Log_Pos: 253 Relay_Master_Log_File: mysql-bin.000001 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 107 Relay_Log_Space: 410 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 1 row in set (0.00 sec) ERROR: No query specified
第五步,serv09延時服務器修改master狀態,開啓slave,查看slave狀態
mysql> change master to master_host='192.168.1.11', master_user='larry', master_password='larry', master_port=3306, master_log_file='mysql-bin.000001', master_log_pos=107; Query OK, 0 rows affected (0.02 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec) mysql> show slave status \G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.11 Master_User: larry Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000001 Read_Master_Log_Pos: 107 Relay_Log_File: serv09-relay-bin.000002 Relay_Log_Pos: 253 Relay_Master_Log_File: mysql-bin.000001 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 107 Relay_Log_Space: 410 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 1 row in set (0.00 sec) ERROR: No query specified
第六步,在沒有使用延時服務器時,serv01創建測試數據庫,可以看到同步服務器serv08和延時服務器serv09已經同步了
serv01 mysql> create database justdb; Query OK, 1 row affected (0.01 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | crm | | justdb | | larry | | larrydb | | mysql | | performance_schema | | test | +--------------------+ 8 rows in set (0.00 sec) serv08 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | justdb | | larrydb | | mysql | | performance_schema | | test | +--------------------+ 6 rows in set (0.03 sec) serv09 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | justdb | | larry | | larrydb | | mysql | | performance_schema | | test | +--------------------+ 7 rows in set (0.00 sec)
第七步,拷貝percona-toolkit-2.1.7-1.noarch.rpm
[root@larrywen ule-mysql]# scp percona-toolkit-2.1.7-1.noarch.rpm 192.168.1.11:/opt [email protected]'s password: percona-toolkit-2.1.7-1.noarch.rpm 100% 1767KB 1.7MB/s 00:00
第八步,主服務器中通過yum安裝percona-toolkit-2.1.7-1.noarch.rpm
[root@serv01 opt]# yum install percona-toolkit-2.1.7-1.noarch.rpm -y
第九步,使用pt-slave-delay工具進行延時設置。可以先查看幫助。
[root@serv01 opt]# pt-slave-delay --help pt-slave-delay starts and stops a slave server as needed to make it lag behind the master. The SLAVE-HOST and MASTER-HOST use DSN syntax, and values are copied from the SLAVE-HOST to the MASTER-HOST if omitted. For more details, please use the --help option, or try 'perldoc /usr/bin/pt-slave-delay' for complete documentation. Usage: pt-slave-delay [OPTION...] SLAVE-HOST [MASTER-HOST] Options: --ask-pass Prompt for a password when connecting to MySQL --charset=s -A Default character set --config=A Read this comma-separated list of config files; if specified, this must be the first option on the command line --[no]continue Continue replication normally on exit (default yes) --daemonize Fork to the background and detach from the shell --database=s -D The database to use for the connection --defaults-file=s -F Only read mysql options from the given file --delay=m How far the slave should lag its master (default 1h). Optional suffix s=seconds, m=minutes, h=hours, d=days; if no suffix, s is used. --help Show help and exit --host=s -h Connect to host --interval=m How frequently pt-slave-delay should check whether the slave needs to be started or stopped (default 1m). Optional suffix s=seconds, m=minutes, h=hours, d=days; if no suffix, s is used. --log=s Print all output to this file when daemonized --password=s -p Password to use when connecting --pid=s Create the given PID file when daemonized --port=i -P Port number to use for connection --quiet -q Don't print informational messages about operation --run-time=m How long pt-slave-delay should run before exiting. Optional suffix s=seconds, m=minutes, h=hours, d=days; if no suffix, s is used. --set-vars=s Set these MySQL variables (default wait_timeout=10000) --socket=s -S Socket file to use for connection --use-master Get binlog positions from master, not slave --user=s -u User for login if not current user --version Show version and exit --version-check=s Send program versions to Percona and print suggested upgrades and problems (default off) Option types: s=string, i=integer, f=float, h/H/a/A=comma-separated list, d=DSN, z=size, m=time Rules: This tool accepts additional command-line arguments. Refer to the SYNOPSIS and usage information for details. DSN syntax is key=value[,key=value...] Allowable DSN keys: KEY COPY MEANING === ==== ============================================= A yes Default character set D yes Default database F yes Only read default options from the given file P yes Port number to use for connection S yes Socket file to use for connection h yes Connect to host p yes Password to use when connecting u yes User for login if not current user If the DSN is a bareword, the word is treated as the 'h' key. Options and values after processing arguments: --ask-pass FALSE --charset (No value) --config /etc/percona-toolkit/percona-toolkit.conf,/etc/percona-toolkit/pt-slave-delay.conf,/root/.percona-toolkit.conf,/root/.pt-slave-delay.conf --continue TRUE --daemonize FALSE --database (No value) --defaults-file (No value) --delay 3600 --help TRUE --host (No value) --interval 60 --log (No value) --password (No value) --pid (No value) --port (No value) --quiet FALSE --run-time (No value) --set-vars wait_timeout=10000 --socket (No value) --use-master FALSE --user (No value) --version FALSE --version-check off
第十步,serv09延時服務器中創建授權用戶
mysql> grant all on *.* to 'rep'@'192.168.1.%' identified by 'larry'; Query OK, 0 rows affected (0.00 sec)
第十一步,實現功能。
[root@serv01 ~]# pt-slave-delay --user='rep' --password='larry' --delay=3m --interval=20s --run-time=30m 192.168.1.19 2013-10-06T19:43:30 slave running 0 seconds behind 2013-10-06T19:43:30 STOP SLAVE until 2013-10-06T19:46:30 at master position mysql-bin.000001/199 命令解釋 --user='rep':延時服務器中授權用戶的用戶名,這裏設置爲rep --password='larry':延時服務器中授權用戶的密碼,這裏設置爲larry --delay=3m:延時同步的時間,這裏設置爲3分鐘 --interval=20s:檢查同步的時間,這裏設置爲20s --run-time=30m:pt-slave-delay的運行時間,這裏設置爲30分鐘 192.168.1.19:延時服務器的IP地址
第十二步,測試,主服務器serv01創建測試數據庫,可以發現同步服務器立馬更新,而延時同步服務器要等3分鐘之後才更新
serv01 mysql> use justdb; Database changed mysql> create table test(id int); Query OK, 0 rows affected (0.01 sec) mysql> insert into test values(1); Query OK, 1 row affected (0.00 sec) serv08 mysql> select * from justdb.test; +------+ | id | +------+ | 1 | +------+ 1 row in set (0.00 sec) serv09 mysql> select * from justdb.test; ERROR 1146 (42S02): Table 'justdb.test' doesn't exist 三分鐘過後查看延時服務器已經同步成功 [root@serv01 ~]# pt-slave-delay --user='rep' --password='larry' --delay=3m --interval=20s --run-time=30m 192.168.1.19 2013-10-06T19:43:30 slave running 0 seconds behind 2013-10-06T19:43:30 STOP SLAVE until 2013-10-06T19:46:30 at master position mysql-bin.000001/199 2013-10-06T19:43:50 slave stopped at master position mysql-bin.000001/199 2013-10-06T19:44:10 slave stopped at master position mysql-bin.000001/199 2013-10-06T19:44:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:44:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:45:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:45:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:45:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:46:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:46:30 no new binlog events 2013-10-06T19:46:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:47:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:47:30 START SLAVE until master 2013-10-06T19:44:30 mysql-bin.000001/492 2013-10-06T19:47:50 slave running 0 seconds behind 2013-10-06T19:47:50 STOP SLAVE until 2013-10-06T19:50:50 at master position mysql-bin.000001/492 2013-10-06T19:48:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:48:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:48:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:49:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:49:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:49:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:50:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:50:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:50:50 no new binlog events 2013-10-06T19:51:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:51:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:51:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:52:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:52:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:52:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:53:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:53:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:53:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:54:10 no new binlog events 2013-10-06T19:54:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:54:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:55:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:55:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:55:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:56:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:56:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:56:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:57:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:57:30 no new binlog events 2013-10-06T19:57:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:58:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:58:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:58:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:59:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:59:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T19:59:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:00:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:00:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:00:50 no new binlog events 2013-10-06T20:01:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:01:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:01:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:02:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:02:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:02:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:03:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:03:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:03:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:04:10 no new binlog events 2013-10-06T20:04:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:04:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:05:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:05:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:05:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:06:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:06:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:06:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:07:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:07:30 no new binlog events 2013-10-06T20:07:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:08:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:08:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:08:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:09:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:09:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:09:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:10:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:10:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:10:50 no new binlog events 2013-10-06T20:11:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:11:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:11:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:12:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:12:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:12:50 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:13:10 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:13:30 slave stopped at master position mysql-bin.000001/492 2013-10-06T20:13:30 Setting slave to run normally mysql> select * from justdb.test; +------+ | id | +------+ | 1 | +------+ 1 row in set (0.00 sec)
四 附延時備份腳本
#!/bin/bash
#
# chkconfig: - 88 12
# description: the mysql ab delay scripts
host=192.168.100.54
user=rep
password=larry
delay=2m
in=15s
prog=/usr/bin/pt-slave-delay
. /etc/init.d/functions
start() {
echo -n "Starting `basename $prog`..."
daemon $prog --host=$host --user=$user --password=$password --delay=$delay --interval=$in --daemonize --log=/var/log/mysql-delay.log
echo
}
stop() {
echo -n "Stopping `basename $prog`..."
killproc $prog
echo
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
*)
echo "Usage: $0 {start|stop|restart}"
exit 1
esac
五 資源下載
percona-toolkit-2.1.7-1.noarch.rpm
http://download.csdn.net/detail/wentasy/6679233
我的郵箱:[email protected] 新浪微博:@jutdb 微信公衆平臺:JustOracle(微信號:justoracle) 數據庫技術交流羣:336882565(加羣時驗證 From CSDN XXX) All is well 2013年12月8日 By Larry Wen
@Wentasy 博文僅供參考,歡迎大家來訪。如有錯誤之處,希望批評指正。原創博文如需轉載請註明出處,謝謝 :) [CSDN博客] |