Error: Could not read host and service status information!

The most common cause of this error message (especially for new users), is the fact that Nagios is not actually running. If Nagios is indeed not running, this is a normal error message. It simply indicates that the CGIs could not obtain the current status of hosts and services that are being monitored. If you’ve just installed things, make sure you read the documentation on starting Nagios

Nagios 服务器监控简介

Nagios是一款开源的电脑系统和网络监视工具,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

负载均衡之DNS轮询

DNS服务器将解析请求按照A记录的顺序,随机分配到不同的IP上,这样就完成了简单的负载均衡。下图的例子是:有3台联通服务器、3台电信服务器,要实现“联通用户流量分摊到3台联通服务器、其他用户流量分摊到电信服务器”这个效果的设置