shell 監控cpu,memory,load average

shell 監控cpu，memory，load average，記錄到log，當負載壓力時，發電郵通知管理員。

原理：

1.擷取cpu，memory，load average的數值

2.判斷數值是否超過自訂的範圍，例如（CPU>90%，Memory<10%，load average>2）

3.如數值超過範圍，發送電郵通知管理員。發送有時間間隔，每小時只會發送一次。

4.將數值寫入log。

5.設定crontab 每30秒運行一次。

ServerMonitor.sh

#!/bin/bash# 系統監控,記錄cpu、memory、load average,當超過規定數值時發電郵通知管理員# *** config start ***# 目前的目錄路徑ROOT=$(cd "$(dirname "$0")"; pwd)# 當前伺服器名HOST=$(hostname)# log 檔案路徑CPU_LOG="${ROOT}/logs/cpu.log"MEM_LOG="${ROOT}/logs/mem.log"LOAD_LOG="${ROOT}/logs/load.log"# 通知電郵列表NOTICE_EMAIL='admin@admin.com'# cpu,memory,load average 記錄上一次發送通知電郵時間CPU_REMARK='/tmp/servermonitor_cpu.remark'MEM_REMARK='/tmp/servermonitor_mem.remark'LOAD_REMARK='/tmp/servermonitor_loadaverage.remark'# 發通知電郵間隔時間REMARK_EXPIRE=3600NOW=$(date +%s)# *** config end ***# *** function start ***# 擷取CPU佔用function GetCpu() {    cpufree=$(vmstat 1 5 |sed -n '3,$p' |awk '{x = x + $15} END {print x/5}' |awk -F. '{print $1}')    cpuused=$((100 - $cpufree))    echo $cpuused    local remark    remark=$(GetRemark ${CPU_REMARK})    # 檢查CPU佔用是否超過90%    if [ "$remark" = "" ] && [ "$cpuused" -gt 90 ]; then        echo "Subject: ${HOST} CPU uses more than 90% $(date +%Y-%m-%d' '%H:%M:%S)" | sendmail ${NOTICE_EMAIL}        echo "$(date +%s)" > "$CPU_REMARK"    fi}# 擷取記憶體使用量情況function GetMem() {    mem=$(free -m | sed -n '3,3p')    used=$(echo $mem | awk -F ' ' '{print $3}')    free=$(echo $mem | awk -F ' ' '{print $4}')    total=$(($used + $free))    limit=$(($total/10))    echo "${total} ${used} ${free}"    local remark    remark=$(GetRemark ${MEM_REMARK})    # 檢查記憶體佔用是否超過90%    if [ "$remark" = "" ] && [ "$limit" -gt "$free" ]; then        echo "Subject: ${HOST} Memory uses more than 90% $(date +%Y-%m-%d' '%H:%M:%S)" | sendmail ${NOTICE_EMAIL}        echo "$(date +%s)" > "$MEM_REMARK"    fi}# 擷取load averagefunction GetLoad() {    load=$(uptime | awk -F 'load average: ' '{print $2}')    m1=$(echo $load | awk -F ', ' '{print $1}')    m5=$(echo $load | awk -F ', ' '{print $2}')    m15=$(echo $load | awk -F ', ' '{print $3}')    echo "${m1} ${m5} ${m15}"    m1u=$(echo $m1 | awk -F '.' '{print $1}')    local remark    remark=$(GetRemark ${LOAD_REMARK})    # 檢查是否負載是否有壓力    if [ "$remark" = "" ] && [ "$m1u" -gt "2" ]; then        echo "Subject: ${HOST} Load Average more than 2 $(date +%Y-%m-%d' '%H:%M:%S)" | sendmail ${NOTICE_EMAIL}        echo "$(date +%s)" > "$LOAD_REMARK"    fi}# 擷取上一次發送電郵時間function GetRemark() {    local remark    if [ -f "$1" ] && [ -s "$1" ]; then        remark=$(cat $1)        if [ $(( $NOW - $remark )) -gt "$REMARK_EXPIRE" ]; then            rm -f $1            remark=""        fi    else        remark=""    fi    echo $remark}# *** function end ***cpuinfo=$(GetCpu)meminfo=$(GetMem)loadinfo=$(GetLoad)echo "cpu: ${cpuinfo}" >> "${CPU_LOG}"echo "mem: ${meminfo}" >> "${MEM_LOG}"echo "load: ${loadinfo}" >> "${LOAD_LOG}"exit 0

crontab

* * * * * /home/xxxx/ServerMonitor.sh* * * * * sleep 30; /home/xxxx/ServerMonitor.sh