用一个简单的脚本诊断linux服务器负载问题

如果您已经做过任何一段时间的管理员，您肯定会发现服务器在CPU使用率或内存利用率和/或负载水平上出现峰值的情况。跑'top'也不会总是给你答案。那么，如何找到那些正在吞噬系统资源以杀死它们的秘密进程呢？...

如果您已经做过任何一段时间的管理员，您肯定会发现服务器在CPU使用率或内存利用率和/或负载水平上出现峰值的情况。跑'top'也不会总是给你答案。那么，如何找到那些正在吞噬系统资源以杀死它们的秘密进程呢？

下面的脚本可能会有所帮助。它是为一个web服务器编写的，因此它的一些部分专门寻找httpd进程，还有一些部分处理MySQL。根据您的服务器部署，只需注释/删除这些部分并添加其他部分。它应该作为一个起点。

此版本脚本的先决条件是在GNU通用公共许可证mytop下发布的一些免费软件（可在http://jeremy.zawodny.com/mysql/mytop/)这是一个检查MySQL执行情况的极好工具。它正在变老，但对我们的目的来说仍然很有用这里。另外，我使用mutt作为mailer–您可能需要将脚本更改为只使用linux内置的“mail”实用程序。我每小时通过cron运行一次；根据需要进行调整。哦–这个脚本需要以root身份运行，因为它确实从服务器的某些受保护区域读取数据。

我们开始吧，好吗？

首先，设置脚本变量：

#!/bin/bash # # Script to check system load average levels to try to determine # what processes are taking it overly high... # # 07Jul2010 tjones # # set environment dt=`date +%d%b%Y-%X` # Obviously, change the following directories to where your log files actually are kept tmpfile="/tmp/checkSystemLoad.tmp" logfile="/tmp/checkSystemLoad.log" msgLog="/var/log/messages" mysqlLog="/var/log/mysqld.log" # the first mailstop is standard email for reports. Second one is for cell phone (with a pared down report) mailstop="[email protected]" mailstop1="[email protected]" machine=`hostname` # The following three are for mytop use - use a db user that has decent rights dbusr="username" dbpw="password" db="yourdatabasename" # The following is the load level to check on - 10 is really high, so you might want to lower it. levelToCheck=10

接下来，检查负载级别以查看脚本是否应继续：

# Set variables from system: loadLevel=`cat /proc/loadavg | awk '{print $1}'` loadLevel=$( printf "%0.f" $loadLevel )

# if the load level is greater than you want, start the script process. Otherwise, exit 0

if [ $loadLevel -gt $levelToCheck ]; then echo "" > $tmpfile echo "**************************************" >>$tmpfile echo "Date: $dt " >>$tmpfile echo "Check System Load & Processes " >>$tmpfile echo "**************************************" >>$tmpfile

并继续检查，将结果写入临时文件。根据您的情况在此处添加或删除项目：

# Get more variables from system: httpdProcesses=`ps -def | grep httpd | grep -v grep | wc -l`

# Show current load level: echo "Load Level Is: $loadLevel" >>$tmpfile echo "*************************************************" >>$tmpfile

# Show number of httpd processes now running (not including children): echo "Number of httpd processes now: $httpdProcesses" >>$tmpfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

# Show process list: echo "Processes now running:" >>$tmpfile ps f -ef >>$tmpfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

# Show current MySQL info: echo "Results from mytop:" >>$tmpfile /usr/bin/mytop -u $dbusr -p $dbpw -b -d $db >>$tmpfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

注意，使用top命令，我们正在写入两个临时文件。一种是把小得多的信息传送到**上。如果你不想在凌晨三点收到紧急的**警报，你可以去掉这个（在脚本后面的第二个邮件例程中去掉）。

# Show current top: echo "top now shows:" >>$tmpfile echo "top now shows:" >>$topfile /usr/bin/top -b -n1 >>$tmpfile /usr/bin/top -b -n1 >>$topfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

更多检查：

# Show current connecti***: echo "netstat now shows:" >>$tmpfile /bin/netstat -p >>$tmpfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

# Check disk space echo "disk space:" >>$tmpfile /bin/df -k >>$tmpfile echo "*************************************************" >>$tmpfile echo "" >>$tmpfile

然后将临时文件内容写入一个更永久的日志文件，并将结果通过电子邮件发送给相关方。第二封邮件是精简后的结果，仅由“top”中的标准组成：

# Send results to log file: /bin/cat $tmpfile >>$logfile

# And email results to sysadmin: /usr/bin/mutt -s "$machine has a high load level! - $dt" -a $mysqlLog -a $msgLog $mailstop >$logfile

然后，一些客房管理和出口：

# And then remove the temp file: rm $tmpfile rm $topfile fi

# exit 0

希望这能帮助别人。完全组装的脚本是：

#!/bin/bash # # Script to check system load average levels to try to determine what processes are # taking it overly high... # # set environment dt=`date +%d%b%Y-%X` # Obviously, change the following directories to where your log files actually are kept tmpfile="/tmp/checkSystemLoad.tmp" logfile="/tmp/checkSystemLoad.log" msgLog="/var/log/messages" mysqlLog="/var/log/mysqld.log" # the first mailstop is standard email for reports. Second one is for cell phone (with a pared down report) mailstop="[email protected]" mailstop1="[email protected]" machine=`hostname` # The following three are for mytop use - use a db user that has decent rights dbusr="username" dbpw="password" db="yourdatabasename" # The following is the load level to check on - 10 is really high, so you might want to lower it. levelToCheck=10 # Set variables from system: loadLevel=`cat /proc/loadavg | awk '{print $1}'` loadLevel=$( printf "%0.f" $loadLevel )