MySQL：备份策略 - 主或从？

Question

我们设置了MySQL（5.1版本）与主从设置。 我们需要提出备份策略，我们将使用mysqldump。

我们打算使用flushlogs,master-date=2和single-transaction选项。

我只想知道从哪个节点更好地运行Master或Slave备份？

Answer 1

以下是我如何很久以前解决这个问题：

#!/usr/bin/ksh 
date=`date +%y%m%d` 
mysql -u root db_name -e "flush tables with read lock;" 
mysqldump -u root -pYrPass --add-drop-table --add-locks natl_inv > /path/to/backup/db_name$date 
mysql -u root -e "reset master;" 
mysql -u root db_name -e "unlock tables;" 
mysql -u root –pYrPass db_name < /path/to/backup/db_name$date 
mysql -u root -e "flush logs;" 

在从属服务器（S）：使用show从状态命令来验证您是在与主机同步。如果你想重新同步到主运行：

slave stop; 
reset slave; 
slave start; 

您可能需要停止MySQL中，删除从斌的日志文件，然后重新启动并运行以上（这是对我们很重要，因为我们有一个流氓应用程序镦从站上的mysql配置）。

这个策略对我们的目的非常有益。确保并测试以确保它符合您的需求。

Answer 2

您应该在从设备上运行备份，以便主设备不会以任何方式中断，并且主设备可以保持生产模式。

下面是一个脚本来备份mysql数据的奴隶，只保留最近7个备份

MYSQL_USER=root 
MYSQL_PASS=rootpass 
MYSQL_CONN="-u${MYSQL_USER} -p${MYSQL_PASS}" 
BACKUP_HOME=/some/path/to/your/backups 
BACKUP_TIME=`date +"%Y%m%d_%H%M%S"` 
BACKUP_FILE=${BACKUP_HOME}/MySQLData_${BACKUP_TIME}.sql 
BACKUP_GZIP=${BACKUP_FILE}.gz 

MYSQLDUMP_OPTIONS="--single--transaction --routines --triggers" 
# 
# Stop Replication 
# Dump the Data 
# Resume Replication 
# 
mysql ${MYSQL_CONN} -ANe"STOP SLAVE" 
mysqldump ${MYSQL_CONN} ${MYSQLDUMP_OPTIONS} -A | gzip > ${BACKUP_GZIP} 
mysql ${MYSQL_CONN} -ANe"START SLAVE" 

# 
# Rotate Out Old Backups based on BACKUPS_TO_KEEP 
# 
cd ${BACKUP_HOME} 
FILES_TO_DELETE=/tmp/BackupFilesToDelete.txt 
BACKUPS_TO_KEEP=7 
BACKUPS_ON_HAND=`ls MySQLData_*.gz | wc -l` 
if [ ${BACKUPS_ON_HAND} -gt ${BACKUPS_TO_KEEP} ] 
then 
    ((DIFF = BACKUPS_ON_HAND - BACKUPS_TO_KEEP)) 
    ls -l MySQLData_*.gz | head -${DIFF} > ${FILES_TO_DELETE} 
    for FIL in `cat ${FILES_TO_DELETE}` ; do rm -f ${FIL} ; done 
fi 

不能使用--master-data=2因为备份是从奴隶，而不是法师。如果您升级MySQL 5.5，则可以使用MYSQLDUMP_OPTIONS中的--dump-slave来捕获主设备的二进制日志和SHOW SLAVE STATUS\G的位置。您将在转储的第23行找到--dump-slave的输出。

如果您希望继续使用MySQL 5.1和你想记录从主坐标，使用此

MYSQL_USER=root 
MYSQL_PASS=rootpass 
MYSQL_CONN="-u${MYSQL_USER} -p${MYSQL_PASS}" 
BACKUP_HOME=/some/path/to/your/backups 
BACKUP_TIME=`date +"%Y%m%d_%H%M%S"` 
BACKUP_COOR=${BACKUP_HOME}/MySQLCoor_${BACKUP_TIME}.txt 
BACKUP_FILE=${BACKUP_HOME}/MySQLData_${BACKUP_TIME}.sql 
BACKUP_GZIP=${BACKUP_FILE}.gz 

MYSQLDUMP_OPTIONS="--single--transaction --routines --triggers" 
# 
# Stop Replication 
# Dump the Data 
# Capture Master Coordinates 
# Resume Replication 
# 
mysql ${MYSQL_CONN} -ANe"STOP SLAVE" 
mysqldump ${MYSQL_CONN} ${MYSQLDUMP_OPTIONS} -A | gzip > ${BACKUP_GZIP} 
mysql ${MYSQL_CONN} -Ae"SHOW SLAVE STATUS\G" > /tmp/SSS.txt 
grep "Relay_Master_Log_File:" /tmp/SSS.txt > ${BACKUP_COOR} 
grep "Exec_Master_Log_Pos:" /tmp/SSS.txt >> ${BACKUP_COOR} 
mysql ${MYSQL_CONN} -ANe"START SLAVE" 
# 
# Rotate Out Old Backups based on BACKUPS_TO_KEEP 
# 
cd ${BACKUP_HOME} 
FILES_TO_DELETE=/tmp/BackupFilesToDelete.txt 
BACKUPS_TO_KEEP=7 
BACKUPS_ON_HAND=`ls MySQLData_*.gz | wc -l` 
if [ ${BACKUPS_ON_HAND} -gt ${BACKUPS_TO_KEEP} ] 
then 
    ((DIFF = BACKUPS_ON_HAND - BACKUPS_TO_KEEP)) 
    ls -l MySQLData_*.gz | head -${DIFF} > ${FILES_TO_DELETE} 
    for FIL in `cat ${FILES_TO_DELETE}` ; do rm -f ${FIL} ; done 
fi 

如果你想在主自转二进制日志，只是在主

配置此

[mysqld] 
expire-logs-days=7 

试试看！