【监测软件之Munin 】

Munin is a networked resource monitoring tool that can help analyze resource trends and "what just happened to kill our performance?" problems. 

It is designed to be very plug and play. A default installation provides a lot of graphs with almost no work.

 

munin是用于Linux系统（也可以监控windows系统）的监控软件。munin除了可以监控系统的各项数值之外，最大的好处是可以自己编写插件自定义监控需要的数值。

 

Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. After completing a installation a high number of monitoring plugins will be playing with no more effort.

Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine "what's different today" when a performance problem crops up. It makes it easy to see how you're doing capacity-wise on any resources.

Munin uses the excellent ​RRDTool (written by Tobi Oetiker) and the framework is written in Perl, while plugins may be written in any language. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for data. It then stores the data in RRD files, and (if needed) updates the graphs. 

One of the main goals has been ease of creating new plugins (graphs).

Munin 是一个非常好用安装和设置方便的监测软件，可监控核心系统资源，包括内存、磁盘、CPU 占用、服务器应用如 MySQL、Apache 和 Squid 等。

 

 

 

Munin默认已经有了磁盘IO、流量统计、进程、Sendmail、CPU、内存等情况统计，从Munin自动绘制的图表中，你可以看到这些项目每天、每周、每月和每年的使用变化情况。

 

Munin-Master

The master is responsible for all central Munin-related tasks.

It regularly connects to the various nodes, and then synchronously asks for the various metrics configuration and values and stores the data in RRD <http://oss.oetiker.ch/rrdtool/> files.

On the fly the values are checked against limits (that you may set) and the Munin-Master will croak, if values go above or below the given thresholds.

Here we also generate the graphs, as this is a heavy task that needs some resources. Recent versions of Munin use cgi-graphing to generate graphs only when the user want’s to see them.

 

 

Munin-Node

The node is a small agent running on each monitored host. We can have agent-less monitoring but this is a special case that will be addressed later.

Note that an usual setup involves having a node running also on the master host, in order to munin to monitor itself.

 

 

Munin-Plugin

The munin plugin is a simple executable, which role is to gather one set of facts about the local server (or fetching data from a remote machine via SNMP)

The plugin is called with the argument “config” to get metadata, and with no arguments to get the values. These are mandatory arguments for each plugin. We have some more standard arguments, which play a role in the process of automatic configuration.