nagios简介：
Nagios是一款开源的免费网络监视工具，能有效监控Windows、Linux和Unix的主机状态，交换机路由器等网络设置，打印机等。在系统或服务状态异常时发出邮件或短信报警第一时间通知网站运维人员，在状态恢复后发出正常的邮件或短信通知。
本篇文章将详细说明如何在ubuntu12.04 server 上安装nagios，并监控本机基本信息。
nagios监控主服务器及被监控服务器的配置：《ubuntu 安装配置 nagios》 ，《ubuntu nagios 配置监控远程主机》
3).依赖包安装
4).配置监控mysql的命令 vi /usr/local/nagios/etc/objects/commands.cfg 添加 define command{ command_line $USER1$/check_mysql_health --hostname $ARG1$ --port $ARG2$ --username $ARG3$ --password $ARG4$ --mode $ARG5$ } 增加： define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_slave_io check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!slave-io-running notifications_enabled 1 } define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_slave_sql check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!slave-sql-running notifications_enabled 1 } define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_connection_time check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!connection-time notifications_enabled 1 } define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_threads_connected check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!threads-connected notifications_enabled 1 } define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_slow_queries check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!slow-queries
notifications_enabled 1 } define service{ use generic-service ; Name of service template to use host_name linux-machine1 service_description check_mysql_table_lock_contention check_command check_mysql_health!192.168.0.103!3306!nagios!nagios1234!table-lock-contention notifications_enabled 1 } 7). 没有错误的话重新启动nagios killall nagios /usr/local/nagios/bin/nagios -d /usr/local/nagios/etc/nagios.cfg
command_name check_mysql_health
5).在监控该主机的配置文件中增加相应的service
vi /usr/local/nagios/etc/machines/linuxmachine1.cfg
6).检查刚才的修改是否有语法错误
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
