Description
The Multi Router Traffic Grapher (MRTG) is a tool to
monitor the traffic load on network links. MRTG generates HTML pages containing
PNG images which provide a LIVE visual representation of this traffic. Check http://www.stat.ee.ethz.ch/mrtg/
to see what it does.
Go to http://oss.oetiker.ch/mrtg
for all the details about mrtg.
# 注释 ：MRTG 是一个监测网络链路流量的工具，生成 HTML 页面（内嵌
PNG 图片）
Highlights
# 注释 ：MRTG
的亮点 Portable
MRTG works on most UNIX platforms and Windows
NT.
# 注释：可移植性。MRTG 可以在 UNIX 和 WINDOWS
上运行
Perl
MRTG is written in Perl and comes with full
source.
# 注释 ：MRTG 是用 Perl
写的，附带源代码
Portable SNMP
MRTG Uses a highly portable SNMP implementation
written entirely in Perl (thanks to Simon Leinen). There is no need to install
any external SNMP package.
SNMPv2c support
MRTG can read the new SNMPv2c 64bit counters. No
more counter wrapping.
# 注释 ：MRTG 能够读取 SNMP v2c 的 64 bit
计数器。
Reliable Interface
Identification
Router interfaces can be identified by IP
address, description and ethernet address in addition to the normal interface
number.
# 注释 ：MRTG 可以通过 ip地址、描述信息、MAC
地址来区分不同的物理接口
Constant size Logfiles
MRTG's logfiles do NOT grow thanks to the use of
a unique data consolidation algorithm.
# 注释 ：由于 MRTG
采取了数据合并算法，所以日志大小固定。
Automatic Configuration
MRTG comes with a set of configuration tools
which make configuration and setup very simple.
# 注释 ：MRTG
通过提供一系列的工具实现自动配置
Performance
Time critical routines are written in C (thanks
to the initiative of Dave Rand my Co-Author).
# 注释：重要的例程都是用 C
写的，保证了软件的性能
GIF free Graphics
Graphics are generated directly in PNG format
using the GD library by Thomas Boutell.
# 注释 ：图片是使用 GD 库生成的 PNG
格式。
Customizability
The look of the webpages produced by MRTG is
highly configurable.
# 注释 ：MRTG
生成的页面外观可以自由的修改
RRDtool
MRTG has built-in hooks for using RRDtool. If
you are strapped for performance this may help.
# 注释 ：MRTG 内建支持 RRDtool
Details
MRTG consists of a Perl script which uses SNMP
to read the traffic counters of your routers and a fast C program which logs the
traffic data and creates beautiful graphs representing the traffic on the
monitored network connection. These graphs are embedded into webpages which can
be viewed from any modern Web-browser.
# 注释 ：MRTG 使用一个 Perl 脚本，通过
SNMP 读取流量信息。并通过 C 程序快速记录流量数据日志和生成图表
In addition to a detailed daily view, MRTG also
creates visual representations of the traffic seen during the last seven days,
the last five weeks and the last twelve months. This is possible because MRTG
keeps a log of all the data it has pulled from the router. This log is
automatically consolidated so that it does not grow over time, but still
contains all the relevant data for all the traffic seen over the last two years.
This is all performed in an efficient manner. Therefore you can monitor 200 or
more network links from any halfway decent UNIX box.
# 注释 ：MRTG
除了提供每天的流量图外，还能提供每周的、每5周、每年的图表。
[color="#0000ff"]# 但即使这样日志文件也不会太大。
MRTG is not limited to monitoring traffic,
though. It is possible to monitor any SNMP variable you choose. You can even use
an external program to gather the data which should be monitored via MRTG.
People are using MRTG, to monitor things such as System Load, Login Sessions,
Modem availability and more. MRTG even allows you to accumulate two or more data
sources into a single graph.
# 注释 ：MRTG 不限于监测流量，任何 SNMP
对象都可以被监测。
# 甚至还可以使用外部程序来收集数据，再交给 MRTG
。例如监测系统负载、会话数量等等
History
In 1994 I was working at a site where we had one
64kbit line to the outside world. Obviously, everybody was interested in knowing
how the link was performing. So I wrote a quick hack which created a constantly
updated graph on the web that showed the traffic load on our Internet link. This
eventually evolved into a rather configurable Perl script called MRTG-1.0 which
I released in spring 1995. After a few updates, I left my job at DMU to start
work at the Swiss Federal Institute of Technology. Due to lack of time I had to
put MRTG aside. One day in January of 1996, I received email from Dave Rand
asking if I had any ideas why MRTG was so slow. Actually, I did. MRTG's
programming was not very efficient and it was written entirely in Perl. After a
week or so, Dave wrote back to me and said he had tried what I had suggested for
improving MRTG's speed. Since the changes did not help much, he had decided to
rewrite the time-critical sections of MRTG in C. The code was attached to his
email. His tool increased the speed of MRTG by a factor of 40! This got me out
of my 'MRTG ignorance' and I started to spend my spare time developing of
MRTG-2.
Soon after MRTG-2 development had begun I
started to give beta copies to interested parties. In return I got many feature
patches, a lot of user feedback and bug fixes. The product you are getting now
wouldn't be in this state if it hadn't been for the great contributions and
support I received from of many people. I would like to take this opportunity to
thank them all. (See the files CHANGES for a long list of folk people who helped
to make MRTG what it is today.)
Command-line
Mrtg is also the name of the script you have to
run to poll data and generate the graphs. Most configuration is set through the
configuration file; some command-line options exist all the
same.
# 注释 ：mrtg
也是用来轮询的脚本的名称，可以带下面的参数 --user username and --group groupname
Run as the given user and/or group. (Unix Only)
# 注释 ：--user ,
--group 表示以什么用户/用户组运行
--lock-file filename
Use an
alternate lock-file (the default is to use the configuration-file appended with
_l).
# 注释 ：--lock-file
指定锁文件。默认是配置文件名后面加上 "_l"
[color="#ff0000"]
--confcache-file filename
Use an
alternate confcache-file (the default is to use the configuration-file appended
with .ok)
--logging filename|eventlog
If this is set to writable filename, all output
from mrtg (warnings, debug messages, errors) will go to filename. If you
are running on Win32 you can specify eventlog instead of a filename which
will send all error to the windows event log. NOTE:Note, there
is no Message DLL for mrtg. This has the side effect that the windows event
logger will display a nice message with every entry in the event log, complaing
about the fact that mrtg has no message dll. If any of the Windows folks want to
contribute one, they are welcome.
--daemon
Put MRTG into the background, running as a
daemon. This works the same way as the config file option, but the switch is
required for proper FHS operation (because /var/run is writable only by root)
--log-only
Only update the logfile, do not produce graphics
or html pages
# 注释 ：--log-only 只更新日志，不生成图表或者
HTML 页面
--debug=s
Enable debug options. The argument of the debug
option is a comma separated list of debug values:
cfg -
watch the config file reading
dir -
directory mangeling
base - basic program flow
tarp - target
parser
snpo - snmp polling
fork - forking view
time - some timing
info
log -
logging of data via rateup or rrdtool