Shell script checks the memcache process and automatically restarts

Shell script checks the memcache process and automatically restarts
Revised version:

#! /Bin/sh
# Check memcache process and restart if down

Mm_bin = "/usr/local/bin/memcached"
Mm_log = "/home/xxx/memcached_check.log"
Mm_ports = ("11211" "11212 ")
Mm_param = ("-d-m 20480-p 11211-u www" "-d-m 256-p 11212-u www ")
Mm_count =$ {# mm_ports [@]}

T = $ (date-d "today" + "% Y-% m-% d % H: % M: % S ")
I = 0
While [$ I-lt $ mm_count]
Do
Mm_exists = 'ps-ef | grep "memcached" | grep "$ {mm_ports [$ I]}" | grep-v grep | wc-l'

If ["$ mm_exists" = "0"]; then
$ {Mm_bin }$ {mm_param [$ I]} 2> & 1>/dev/null &
Echo "$ {t }:: {mm_bin }$ {mm_param [$ I]}" >$ {mm_log}
Fi

Let I ++
Done

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Add as automatic execution:
# Crontab-e
*/10 */bin/sh/home/xxx/memcached_check.sh

The system automatically executes memcached_check.sh every 10 minutes.

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Backup shell statement:

# Check the mysql status
PORT = 'netstat-na | grep "LISTEN" | grep "3306" | awk '{print $4}' | awk-F. '{print $2 }''
If ["$ PORT"-eq "3306"]

# Check the CPU usage of mysql
Mysql_cpu = 'top-U root-B-n 1 | grep mysql | awk '{print $10}' | awk-F. '{print $1 }''
# If the mysql cpu load is greater than 80, restart mysql.
If ["$ mysql_cpu"-ge "80"]

# Obtain relevant information
Ps-ef | grep "memcached" | grep-v "grep" | wc-l
Ps-ef | grep "memcached" | grep "11211" | grep-v "grep" | wc-l
Ps aux | grep "memcached" | grep-v "grep" | awk '{sum + = $4; n ++}; END {print sum }'
Ps aux | grep "memcached" | grep-v "grep" | awk '{printf $1 }'

MYPORT = 'netstat-na | grep "tcp" | grep "3306" | awk-F [: ""] + '{print $5 }''
HAPORT = 'netstat-na | grep "udp" | grep "694" | awk-F [: ""] + '{print $5 }''
PING = 'Ping-c 5 www.linuxtone.org | awk-F, '/packets/{print $3}' | cut-c 2-| awk' {print $1 }''
DB1IP = 'ifconfig eth0 | awk '/inet/{print $2}' | cut-c 6 -'

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Shell if statement:
-B. returns true if the file exists and is a block file.
-C: returns true if the file exists and is a character file.
-D. If pathname exists and is a directory, true is returned.
-E: returns true if the file or directory specified by pathname exists.
-F returns true if the file exists and is a regular file
-G returns true if the file or directory specified by pathname exists and the SGID bit is set.
-H returns true if the file exists and is a symbolic link file. This option is invalid in some old systems.
-K. If a file or directory specified by pathname exists and a "Sticky" bit is set, the system returns the true value.
-P: returns true if the file exists and is a command pipeline.
-R: returns true if the file or directory specified by pathname exists and is readable.
-S: returns true if the file size is greater than 0.
-U returns true if a file or directory specified by pathname exists and SUID is set.
-W returns true if the file or directory specified by pathname exists and is executable. A directory must be executable for its content access.
-O returns true if a file or directory specified by pathname exists and the user specified by the valid user ID of the current process is owned by it.

Comparison character writing in UNIX Shell:
-Eq equals
-Ne is not equal
-Gt greater
-Lt is less
-Le is less than or equal
-Ge is greater than or equal
-Z empty string
= Two equal characters
! = Two characters
-N non-empty string

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Crontab information:

Basic Format:
* *** Command
Hour, day, month, and week commands

The 1st column indicates minute 1 ~ 59. Each minute is represented by * or */1, and */10 indicates every 10 minutes.
The first column indicates the hour 1 ~ 23 (0 indicates 0 points)
The 3rd column indicates the date 1 ~ 31
The 4th column indicates the month 1 ~ 12
The Identification Number of column 5th is from day of the week to day ~ 6 (0 indicates Sunday)