squid內存監控腳本

oom_of_squid

用於監控服務器上的squid進程，保證對用戶服務的穩定。

此進程意欲以守護進程模式運行，能夠這樣使用：./oom_of_squid &

主要功能：

監控配置過的每一個squid進程，保證它的內存佔用看似正常；
確保進程PID和PID文件一致；
squid進程掛掉後啓動之；
squid進程佔用的內存超過設置的閥值則重啓之；
系統可用內存低於閥值，則選擇一個squid進程重啓之；
默認每3秒檢查一次；

注意事項：

`echo squid7[0-9].conf`在gentoo和CentOS上的行爲不同，到CentOS下應用可能須要改成`ls squid7[0-9].conf`；
/proc/$PID/comm 在較新的內核上纔有這個接口，使用舊內核須要另想辦法；
/etc/init.d/squid_multi_instance是我重寫過的進程管理腳本（還有bug），使用「標準」腳本的人須要本身改一下；
系統可用內存閥值應該適當高於系統自身的oom閥值；
用於全內存式緩存更好，由於不用顧忌狀態文件的同步。
我設置的配置文件中，squid7[0-9].conf是carp-child，用於緩存文件；squid8[0-9].conf是carp-parent，用於決定URL在集羣中的分佈。

附件爲腳本。望用的上的同仁多提寶貴意見！！！

#!/bin/bash # 功能: #    在系統可用內存很小時選取一個squid進程重啓 #    檢查各進程健康情況 MAIL="gongfan193@gmail.com"        # 設置本身的郵箱 MAIL_FROM="oom_of_squid@gwbnsh.net.cn" CHECK_INTERVAL="3s"        # 檢查時間間隔 THRESHOLD_LOW_MEM="90"            # MB,低內存閥值; 必須大於vm.min_free_kbytes THRESHOLD_CHILD_MAX_MEM="200"    # MB,child持有內存大於此值就重啓 THRESHOLD_EMERG="100"            # MB,LEVEL="emerg"時重啓進程的閥值 LEVEL="normal"    # 內存級別,可用內存較低時設置爲emerg; 正常狀況下應該是空變量 LOG="$0.log" # 探測配置文件,70-79之間的端口爲parent,80-87爲child CONFIG_LOCATION="/etc/squid/" PARENT_CONF=$(cd $CONFIG_LOCATION; echo squid7[0-9].conf) CHILD_CONF=$(cd $CONFIG_LOCATION; echo squid8[0-9].conf) ALL_CONF="$PARENT_CONF $CHILD_CONF" # disable killing by oom echo "-17" > /proc/self/oom_adj all_free_mem() {     free -m | awk '/^Mem:/ {print ($4 + $6 + $7)}'    # 單位是MB } squid_instance_mem() {     INSTANCE=${CONF%.conf}     PID_FILE="/var/run/$INSTANCE.pid"     [[ -e $PID_FILE ]] && PID_FROM_FILE=`cat $PID_FILE` || PID_FROM_FILE=""     # 檢查名稱和進程號是否對應     if [ -e $PID_FILE ]; then         [[ x$PID_FROM_FILE != "x" ]] && grep -q squid /proc/$PID_FROM_FILE/comm || false     else         echo "$INSTANCE pid file not match to squid" >> $LOG     fi     # 佔用的內存數量     RSS=`awk '/^VmRSS:/ {printf "%d\n", $2/1024}' /proc/$PID_FROM_FILE/status` } keep_processes_health() {     # 檢查全部進程,若是掛了,修正一下     for CONF in $ALL_CONF; do         INSTANCE=${CONF%.conf}         PID_FILE="/var/run/$INSTANCE.pid"         STATE_FILE="/var/lib/init.d/started/$INSTANCE"         [[ -e $PID_FILE ]] && PID_FROM_FILE=`cat $PID_FILE` || PID_FROM_FILE=""         PID_RUNNING=`ps axo user,pid,cmd | awk '/^squid/ && /'$CONF'/ {print $2}'`         if [ x$PID_RUNNING = "x" ]; then             # 進程不存在: 啓動進程             process_state="not_running"             echo "`date +%F\ %T` $INSTANCE state is $process_state, restarted" >> $LOG             [[ -e $PID_FILE ]] && /bin/rm -f $PID_FILE             [[ -e $STATE_FILE ]] && /bin/rm -f $STATE_FILE             /etc/init.d/squid_multi_instance start ${INSTANCE#squid} >/dev/null 2>&1             notify_admin &         elif [ x$PID_FROM_FILE = "x" ]; then             # pid文件有問題: 修正             process_state="bad_pid_file"             if echo $PID_RUNNING > $PID_FILE; then                 process_state="good"                 echo "fixed pid file of $INSTANCE at `date +%F\ %T`" >> $LOG             else                 echo "can not write $PID_FILE" >> $LOG                 process_state="pid_file_not_writeable"                 notify_admin &             fi         elif [ x$PID_FROM_FILE != x$PID_RUNNING ]; then             # 什麼狀況下會這樣呢...             process_state="pid_not_equal"             if echo $PID_RUNNING > $PID_FILE; then                 echo "fixed $process_state of $INSTANCE at `date +%F\ %T`" >> $LOG                 notify_admin &             else                 echo "can not write $PID_FILE" >> $LOG                 process_state="$process_state pid_file_not_writeable"                 notify_admin &             fi         elif [ x$PID_FROM_FILE = x$PID_RUNNING ]; then             # 運行良好             process_state="good"             continue         else             process_state="unknow"             notify_admin &         fi     done     unset process_state } restart_process() {     INSTANCE=${CONF%.conf}     /etc/init.d/squid_multi_instance restart ${INSTANCE#squid} >/dev/null 2>&1     notify_admin & } pick_and_restart_parent() {     # 重啓佔用內存最大的進程     for CONF in $PARENT_CONF; do         squid_instance_mem         PARENT_MEM="$PARENT_MEM\n$RSS $CONF"     done     PARENT_MEM_MAX=`echo -e $PARENT_MEM | sort -n | tail -1`     if [ -n $PARENT_MEM_MAX ]; then         CONF=`echo $PARENT_MEM_MAX | awk '{print $2}'`         restart_process         echo "restarted parent ${CONF%.conf} at `date +%F\ %T`" >> $LOG     else         echo "unknow error in pick_and_restart_parent" >> $LOG     fi } pick_and_restart_child() {     # 正常狀況下重啓內存大於300M的進程; 緊急狀況下重啓大於100M的進程     for CONF in $CHILD_CONF; do         squid_instance_mem         if [ $RSS -gt $THRESHOLD_CHILD_MAX_MEM ]; then             process_state="over_THRESHOLD_CHILD_MAX_MEM"             echo "$process_state restarted child ${CONF%.conf} at `date +%F\ %T`" >> $LOG             restart_process         else             true         fi     done     if [ x$LEVEL = "xemerg" ]; then         for CONF in $CHILD_CONF; do             squid_instance_mem             [[ $RSS -gt $THRESHOLD_EMERG ]] && (process_state="over_THRESHOLD_EMERG"; restart_process)         done     else         true     fi } pick_and_restart_one() {     # restart a child first     pick_and_restart_child          # memory still low, restart a parent     [[ `all_free_mem` -lt $THRESHOLD_LOW_MEM ]] && pick_and_restart_parent          # memory still low, restart all child     [[ `all_free_mem` -lt $THRESHOLD_LOW_MEM ]] && \     (CONF="child"; restart_process) } notify_admin() {     sendmail -t -f $MAIL_FROM <<EOF To: $MAIL From: $MAIL_FROM Subject: $INSTANCE on `hostname` restarted 重啓過了 `hostname` 上的 $INSTANCE 進程 $INSTANCE 的最後狀態爲: $process_state 當前系統總剩餘內存爲: `all_free_mem` . EOF } while true; do     keep_processes_health     # child佔用內存大於THRESHOLD_CHILD_MAX_MEM就重啓,不等總內存太低     pick_and_restart_child     if [ `all_free_mem` -lt $THRESHOLD_LOW_MEM ]; then         LEVEL="emerg"         echo "low memory at `date +%F\ %T`" >> $LOG         pick_and_restart_one     else         LEVEL="normal"         sleep $CHECK_INTERVAL     fi done # vim: set sw=4 ts=4: