1) Port judgment method ==> only suitable for local database use
Method 1: if condition judgment method
[root@oldboy scripts]# cat check_db01.sh #!/bin/sh #created by oldboy #mail:oldboy521@ PortNum=`netstat -lnt|grep 3306|wc -l` if [ $PortNum -eq 1 ] then echo "mysqld is running." else echo "mysqld is stoped." fi
Method 2: Conditional expression usage
[root@oldboy scripts]# cat check_db01_1.sh #!/bin/sh #created by oldboy #mail:oldboy521@ PortNum=`netstat -lnt|grep 3306|wc -l` #PortNum=`nmap 10.0.0.189 -p 3306|grep open|wc -l` [ $PortNum -eq 1 ] && echo "mysqld is running."||echo "mysqld is stoped."
Method 3: Use system function display method
[root@oldboy scripts]# cat check_db01_2.sh #!/bin/sh #created by oldboy #mail:oldboy521@ #load functions [ -f /etc//functions ] && . /etc//functions PortNum=`netstat -lnt|grep 3306|wc -l` if [ $PortNum -eq 1 ] then action "mysqld is running." /bin/true else action "mysqld is stoped." /bin/false fi
2) Process plus port judgment method ==> only suitable for local database use
[root@oldboy scripts]# cat check_db02.sh #!/bin/sh #created by oldboy #mail:oldboy521@ PortNum=`netstat -lnt|grep 3306|wc -l` ProcessNum=`ps -ef|grep mysql|grep -v grep| wc -l` #echo $PortNum $ProcessNum #exit 1 if [ $PortNum -eq 1 -a $ProcessNum -eq 2 ] then echo "mysqld is running." else echo "mysqld is stoped." fi
Tip: If you are not satisfied, you can also add simulated user access at the same time.
Tips: Script debugging skills
1) The string filtered by grep should not be included in the file name. For example: grep mysql, the file name is check_mysql.sh is not good. Better file names are:
-rw-r--r-- 1 root root 236 Sep 9 22:19 check_db01.sh
-rw-r--r-- 1 root root 293 Sep 9 22:34 check_db02.sh
-rw-r--r-- 1 root root 212 Sep 9 22:49 check_db03.sh
2) When there is no problem with the grammar but the result is incorrect, you can use the following method to troubleshoot:
a) Print the variable result after the variable definition to see if it is consistent with the actual result, such as:
echo $PortNum $ProcessNum
exit 1
b) The method of sh -x check_db02.sh tracks the script execution process. For more debugging solutions, see the SHELL script debugging details in the following SHELL script debugging.
3) Methods to determine whether the remote MySQL service is normal
Method 1: Port Checking method ==> Suitable for use on remote servers (also suitable for local)
[root@oldboy scripts]# cat check_db03.sh #!/bin/sh #created by oldboy #mail:oldboy521@ PortNum=`nmap 10.0.0.189 -p 80|grep open|wc -l` if [ $PortNum -eq 1 ] then echo "mysqld is running." else echo "mysqld is stoped." fi
Tip: There are many ways to use the port, including three methods that are not limited to the following address, ./2561410/942530
For example: you can also use the check_tcp plug-in of nagios.
Method 2: Simulate user (including web server) access method ==> Suitable for use on remote servers (also suitable for local)
[root@oldboy scripts]# cat check_db04.sh #!/bin/sh #created by oldboy #mail:oldboy521@ mysql -S /data/3306/ -e "select version();" >/dev/null 2>&1 if [ $? -eq 0 ] then echo "mysqld is running." else echo "mysqld is stoped." fi
Skill:
1) Use the web to connect the account to simulate access.
Method 3: Simulate the way users use program URL to judge
<?php
/*
#this scripts is created by oldboy
#oldboy QQ:31333741
#site:
#blog:.
#oldboy trainning QQ group: 208160987 226199307 44246017
*/
$link_id=mysql_connect('10.0.0.4','oldboy','oldboy123') or mysql_error();
if($link_id){
echo "mysql successful by oldboy !";
}else{
echo mysql_error();
}
?>
The above method is just a simple judgment. Here is a more professional mysql inspection and processing script that integrates judgment, processing, and alarm.
4) More professional solutions for mysql checking and processing scripts
#!/bin/bash
#created by oldboy QQ 49000448
#date:20100918
MYUSER=root
MYPASS="oldboy"
MYSOCK=/data/3306/
MySQL_STARTUP="/data/3306/mysql"
LOG_PATH=/tmp
LOG_FILE=${LOG_PATH}/mysqllogs_`date +%F`.log
MYSQL_PATH=/usr/local/mysql/bin
MYSQL_CMD="$MYSQL_PATH/mysql -u$MYUSER -p$MYPASS -S $MYSOCK"
#→The way to define all variables seems more professional.$MYSQL_CMD -e "select version();" >/dev/null 2>&1
if [ $? -eq 0 ]
then
echo "MySQL is running! "
exit 0
else
$MySQL_STARTUP start >$LOG_FILE#→Logins are also variables.sleep 5;
$MYSQL_CMD -e "select version();" >/dev/null 2>&1
if [ $? -ne 0 ]
then
for num in `seq 10`#→ Kill mysqld through the for loop. If you really kill, exit the loop or kill every two seconds, a total of 10 times.do
killall mysqld>/dev/null 2>&1
[ $? -ne 0 ] && break;
sleep 2
done
$MySQL_STARTUP start >>$LOG_FILE
fi
$MYSQL_CMD -e "select version();" >/dev/null 2>&1 && Status="restarted" || Status="unknown"#→This logic is more accurate.echo "MySQL status is $Status" >>$LOG_FILE
mail -s "MySQL status is $Status" 31333741@ < $LOG_FILE
#→Send the Status above as the result title to the email, of course you can make text messages and voice calls to alarm.fi
exit