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Four winning ways to monitor machines through Web interfaces

By Ben Martin on November 04, 2008 (9:00:00 AM)

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System administrators need to keep an eye on their servers to make sure things are running smoothly. If they find a problem, they need to see when it started, so investigations can focus on what happened at that time. That means logging information at regular intervals and having a quick way to analyse this data. Here's a look at several tools that let you monitor one or more servers from a Web interface.

Munin

The Munin project is fairly clearly split into the gather and analyse functionality. This lets you install just the package to gather information on many servers and have a single central server to analyse all the gathered information. Munin is also widely packaged, making setup and updates fairly simple.

Munin is written in Perl, ships with a collection of plugins, supports many versions of Unix operating systems, and has a searchable plugin site.

Munin is in the Fedora 9 repository, Debian Etch, and as a 1-Click for openSUSE 11. Again, I used the version from the repository for a 64-bit Fedora 9 machine. The project provides two packages: the munin-node package includes all of the monitoring functionality, and the munin package supports gathering information from machines running munin-node and graphing it via a Web interface. If you have a network of machines, you probably only want to install munin-node on most of them and munin on one to perform analysis on all the collected data.

The main configuration file for munin-node, /etc/munin/munin-node.conf, lets you define where log files are kept, what user to run the monitoring daemon as, what address and port the daemon should bind to, and which hosts are allowed to connect to that address and port to download the collected data. In the default configuration only localhost is allowed to connect to a munin-node.

You configure plugins through individual configuration files in /etc/munin/plugin-conf.d. Munin-node for Fedora is distributed with about three dozen plugins for monitoring a wide range of system and device information.

When you visit http://localhost/munin, Munin displays an overview page showing you links to all the nodes that it knows about and including links to specific features of the nodes, such as disk, network, NFS, and processes. Clicking on a node name shows you a two-column display. Each row shows a graph with the daily statistics on the left and weekly on the right. Clicking on either graph in a row takes you to a details page showing that data for the day, week, month, and year. At the bottom of the details page a short textual display gives more details about the data, including notification of irregular events. For example, in the below screenshot of the details page for free disk space, you can see a warning that one of the filesystems has become quite full.

To get an idea of how well a system or service is running on a daily or weekly basis, the Munin display works well. Unfortunately, the Web interface does not allow you to drill into the data. For example, you might like to see a specific two-hour period from yesterday, but you can't get that graph from Munin.

The plugins site for Munin is quite well done, allowing you to see an example graph for many of the plugins before downloading. A drawback to the plugins site is the search interface, which is very category-oriented. Some full text search would aid users in finding an appropriate plugin. For example, to find the NUT UPS monitoring plugin you have to select either Sensors or "ALL CATEGORIES" first; just being able to throw UPS or NUT into a text box would enable quick cherry-picking of plugins.

A major advantage of Munin is that it ships as separate packages for gathering and analysing information, so you don't need to install a Web server on each node. The additional information at the bottom of the details page should also prod you if some statistic has a value that you should really pay attention too.

Final words

Of these four applications, Cacti offers the best Web interface, letting you select the time interval displayed on your graphs from more predefined settings, and it also lets you explicitly nominate the start and end time you are interested in. By contrast, in collectd, the emphasis is squarely on monitoring your systems, and the provided Web interface is offered purely as an example that might be of interest. Given that collecting and analysing data can be thought of as separate tasks, it would be wonderful if collectd and Cacti could play well together. Unfortunately, setting up Cacti to use collectd-generated files is a long, manual, error-prone process. While both Cacti and collectd are useful projects by themselves, I can't help but think that the combination of the two would be greater than its parts. Monitorix and Munin are easy to install and offer a quick overview of a host, but Monitorix's three graph per row aggregate presentation gives you a better high-level view of your system.

Which one might be best for you? If you spend a lot of time in data analysis or if you plan to allow non-administrators to get a glance of the system statistics, Cacti might be a good project to look into first. If you want to gather information on a system that is already under heavy load, see if collectd can be run without disrupting your system. Munin's support for gathering information from many nodes using different application packages makes it interesting if you are monitoring a small group of similar machines. If you have a single server and want a quick overview of what is happening, either Cacti or Monitorix is worth checking out first.

Ben Martin has been working on filesystems for more than 10 years. He completed his Ph.D. and now offers consulting services focused on libferris, filesystems, and search solutions.

 

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on Four winning ways to monitor machines through Web interfaces

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 24.130.151.91] on November 04, 2008 04:50 PM

Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 93.172.203.232] on November 04, 2008 08:03 PM
Have a look on http://www.xpolog.com for log monitoring, server monitoring and log analysis

Or on http://www.log-viewer.com for log viewer and log monitor for linux, apache and more

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 97.120.82.204] on November 04, 2008 09:18 PM
As you say, it appears that the combination of collectd and cacti would be wonderful. However, I've long been searching for a decent explanation of how to connect the two. I haven't touched Cacti in a long time, otherwise it might seem obvious to me how this could be done, but I'm expecting it isn't. If anyone knows of a good way to do it, I'd love to hear about it.

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 81.21.200.238] on November 04, 2008 10:55 PM
Where is Nagios? none of tools mentioned in the article are as flexible and powerful as Nagios.... I'm disappointed.

http://www.nagios.org/

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 75.50.59.23] on November 04, 2008 10:57 PM
Why not Zenoss? Merging the functionality of cactii and nagios with an easy-to-use interface. http://zenoss.com

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 192.18.37.228] on November 05, 2008 01:15 AM
Don't forget dim_STAT: http://dimitrik.free.fr

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 218.219.203.156] on November 05, 2008 01:38 AM
Those 4 entries in the article do not have notification systems, but just graphing, as far as I can tell. So, Nagios and friends aren't listed for that reason I think. Besides, Nagios may be flexible and powerful but with a huge complication and clutter everywhere I wouldn't think to use it anymore, I'd rather use monit for that, which is much simpler, cleaner and does the job fine. The sheer amount of Nagios frontend tells something is wrong with itself and nothing really changed at version 3 unfortunately.

And there are also those unified server management packages like Zenoss and Zabbix. The latter is quite lightweight and a decent package in my opinion.

collectd seriously needs a decent frontend. Nothing is good if the data collected can't be revised... I don't know why author doesn't even try to start a sub project on that and let someone code it if he doesn't want to.

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Re: Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 65.201.123.212] on November 06, 2008 03:32 PM
I love it when people post negatives about nagios, or about how hard it is to deploy. I've played with Zabbix, HP-Openview, Solarwinds, Zenoss etc... and none aside from Openview can monitor servers with the depth that nagios can. net-snmp is very limited in it's scope to interact with various applications. Openview is out of the question due to cost. Try deploying Zabbix or Zenoss in a 1000 to 1500 server environment running 10,000 to 20,000 checks and watch what kind of hardware it requires to get it deployed. With nagios templating you have to setup your initial checks and the start grouping servers. Also if you can script in bash or perl there is nothing that can't be monitored with nagios. I may be biased because I've used it for 8 years, bouncing from one poser app to the next, but nagios is where I always land for mission critical systems, and it integrates easily with cacti or rrdtool to give you everything you need.

My opinion and everyone knows what they say about those

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 81.137.217.96] on November 05, 2008 07:56 AM
Also missed ganglia [http://ganglia.info/]

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 83.100.197.205] on November 05, 2008 10:28 AM
Don't forget Opsview (http://www.opsview.org/), based upon Nagios, Net-SNMP, RRDtool and the catalyst web fwk.

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 150.3.84.204] on November 05, 2008 02:13 PM
Zabbix for the win.
http://www.zabbix.com/

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 212.112.163.94] on November 12, 2008 03:45 PM
Another tool to check out for enterprise network monitoring, op5 Monitor http://www.op5.com/op5/products/monitor

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Four winning ways to monitor machines through Web interfaces

Posted by: Anonymous [ip: 87.223.154.166] on November 13, 2008 06:31 AM
Take a look at Osmius. http://osmius.net
Its web based interface, service oriented, intrussive and non-intrussive monitoring and open source.

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How can you not mention Zenoss?

Posted by: Anonymous [ip: 194.19.110.133] on November 14, 2008 06:30 AM
http://www.zenoss.com/

Just out in v2.3 with tons of new features.
I've used it alot and it's amazing! Both an community version and a commercial version.

Best regards: in2os

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