Detailed explanation of the implementation of regular backup of MySQL database tables

[root@mysql_bak]# cat mysql_bak.sh
#!/bin/sh
#DATABASE INFO
DB_NAME="ppdb"
DB_USER="root"
DB_PASS="password"
DISPOSE_TABLE="dispose_ticles"
RST_TABLE="match_rst"
DB_IP=100.55.1.129

BIN_DIR="/usr/bin"
BAK_DIR="/home/mysql_bak/data"
DATE=`date +%Y%m%d_%H%M%S`

#mkdir -p $BAK_DIR
#Backup package to form a compressed package $BIN_DIR/mysqldump $DB_NAME $DISPOSE_TABLE > $BAK_DIR/$DISPOSE_TABLE.dump_$DATE.sql
$BIN_DIR/mysqldump $DB_NAME $DISPOSE_TABLE | gzip > $BAK_DIR/$DISPOSE_TABLE.dump_$DATE.sql.gz

$BIN_DIR/mysqldump $DB_NAME $RST_TABLE > $BAK_DIR/$RST_TABLE.dump_$DATE.sql
$BIN_DIR/mysqldump $DB_NAME $RST_TABLE | gzip > $BAK_DIR/$RST_TABLE.dump_$DATE.sql.gz

#Regularly delete the 60-day backup package find $BAK_DIR -name "name_*.sql.gz" -type f -mtime +60 -exec rm {} \; > /dev/null 2>&1

#Delete the specified database table data 30 days ago (the current time minus 30 days)
delete_date=`date --date='30 day ago' +%Y-%m-%d`
echo "delete_date=$delete_date"

#Delete rst table information rst_sql="delete from $RST_TABLE where update_time <= $delete_date order by update_time;";

echo "rst_sql=$rst_sql"
#ret=$(mysql -u $DB_USER -h ${DB_IP} -p${DB_PASS} $DB_NAME -e "$sql");
ret=$(mysql -h${DB_IP} $DB_NAME -e "$rst_sql");
echo $ret

#Delete dispose table information dispose_sql="delete from $DISPOSE_TABLE where judge_time <= $delete_date order by judge_time;";
echo "dispose_sql=$dispose_sql"
ret=$(mysql -h${DB_IP} $DB_NAME -e "$dispose_sql");
echo $ret

[root@mysql_bak]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# For details see man 4 crontabs

# Example of job definition:
# .---------------- minute (0 - 59)
# | .------------- hour (0 - 23)
# | | .---------- day of month (1 - 31)
# | | | .------- month (1 - 12) OR jan,feb,mar,apr ...
# | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# | | | | |
# * * * * * user-name command to be executed
0 1 */30 * * /home/mysql_bak/mysql_bak.sh > /dev/null 2>&1

[root@mysql_bak]# crontab -e
0 1 */30 * * /home/mysql_bak/mysql_bak.sh > /dev/null 2>&1

service crond restart