Monitoring Your Unix Boxen?

Griim asks: "I've been using Linux for years and loving it, and have also worked a bit on a few Sun stations and BSD boxes as well. My question is this: what is the easiest way to keep tabs on all of the activity?"

"I know a few people who 'tail -f' the main log files, or who run 'top' every so-often. These require constant monitoring though, and you could miss essential error messages if you step away for too long. Are there any projects that do this successfully? I've seen a couple out there that started to do this, but appear to be abandoned.

Ideally, I would like some type of all-in-one, that possibly generates a daily (email/web) report of network statistics, user logins, and (web)server traffic/hits, as well as anything 'suspicious' that might be happening, perhaps what apps have been taking most of the processor time, or if any of the daemons have been busier than they normally would be. I know there probably isn't one single app out there that does all of this, so what's the best configuration , for keeping tabs on multiple machines, something I can skim for a minute or two each day, to make sure things are the way they should be? I want to know what works best, and just as importantly, what *doesn't* work (I do realize that relying on a single solution would be bad here too, so if you have more than one suggestion, that would be appreciated)."

Comments

Tripwire

[daeley]

I cron tripwire on an old BSD box I have running and it works well enough. Linxen:

Tripwire.org

FAQ

sourceforge page

Big Brother

[MJArrison]

I've user Big Brother for many years and it is very configurable. You can monitor anything from cpu usage, memory, disk space, available services, to random things like the weather and server room temp.

All that being said, I found it to be flukey in its behavoir. Sometimes it would report that everything was not responding and it had to be punted before I would get the all clear. The other negative is the license. The program consists of nothing more than shell/perl scripts so it's obviously open, but it has some strange clauses about Non-Commercial use.

Overall, I'd recommend trying something else, because BB was unreliable in my use, but YMMV.

Re:Big Brother

[Zocalo]

If you look at, or already use, Big Brother then *please* make sure you read the article on it in issue #60 of Phrack as well. Owing to the way the software is implemented, the thing can be a goldmine of information for hackers and it is *essential* that your BB box is properly secured.

That said, it does appear to be a capable, fully-featured package and I'd guess that as long as you take the proper precautions you should be OK. I can't comment on the stability though; the security concerns I had were enough to cause me to move along to the next product on my list.

Re:Big Brother

[schon]

*please* make sure you read the article on it in issue #60 of Phrack

I've run BB for a number of years, and I got a good laugh from that article.. thanks..

the security concerns I had were enough to cause me to move along to the next product

The thing is, that if you've got security concerns, then you souldn't have a problem with using BB, because you're already aware of what needs to be done to prevent this information leakage.

The article you linked to didn't provide me with anything I didn't know before I originally installed BB - I run BB as an untrusted user without a valid login (why in the world would a daemon process require a password? - just set it to '*', and be done with it.).. and my status page is password protected, and encrypted.

BB's "security" is only a problem for people who don't understand security in the first place. If you know how to adequately secure a box, BB is no different than any other application.

Keep an eye on your network traffic

[forged]

Any network monitoring applet docked to your environment will do for real-time stuff, but for historical logs you should consider keeping MRTG logs as well. MRTG works with *everything* and the log file format it uses doesn't grow over time (magic!)

Re:Keep an eye on your network traffic

[cymen]

I am currently using MRTG but have been reading up on Cricket. Do you, or anyone else, have any opinions on Cricket?

logcheck

[Col. Klink (retired)]

I use logcheck (available as a Debian package). I run it only one one machine and I have all the other machines send their syslogs to that machine.

To quote a recent job candidate I interviewed..

[Nathan Ramella]

'top' apparently is the best tool for monitoring boxen. :)

He's watching you....

[mpechner]

Take a look at big brother. http://bb4.com. Big brother is cross platform and has many hooks. It will monitor all unix and win machines. I do suggest using a UNIX machine as the server. BB has both email and pager support.

The extensions for BB are at http://www.deadcat.net/

I also like tripwire. Checksums of files on the system to know if important files have been changed. last time I used TripWire it has email alerts. The paid for version has an enterprise monitor.

LogWatch is another. Generates email.

Go through your linux and bsd daily, hourly and weekly scripts to see all the tools they run by default. These can be moved to most Unixs. Since most of these are shell and perl rpograms, some might be adaptable under windows using activeXPerl or Cygwin.

The hardest part is fine tuning the emails and alerts to those things you really care about.

MTRG and agreat snmp tool and tied in with BigBrother.

I've has to set these up for security purposes at one site. For monitoring a server fam at another site. A compile farm for doing builds at my current job.

It's all about Nagios...

[Dimwit]

Nagios rocks my socks. Does everything most commercial apps do, and it's free. Rock solid too.

Re:It's all about Nagios...

[Deagol]

Nagios is pretty sweet -- we use it at our shop. It's handy to be notified as soon as a key server goes down.

One thing I like to do personally is randomly pick a startup script (that's actually used in a particular server's configuration), and bury a single line in it that emails me "hostname has rebooted!" as the subject whenever it reboots. That way I know if a machine is ever rebooted with or (more importantly) without my knowledge.

Nagios

[nocomment]

I'm running Nagios. It was SAINT, and before that it was known as SATAN. I've also used big sister before. That's a pretty good big brother clone. Nagios will do what your after though. Just remember that whatever you build will probably take awhile. Creating the config files takes forever.

Re:Nagios

[Mr_Person]

Nope. SATAN was a vulnerability probing tool that came out of SGI quite a while back. SAINT was based on it (at least in function, I don't know if the code was based on it). They have nothing to do with Nagios.

The previous version of Nagios was called Netsaint, but they changed the name to Nagios because of possible trademark problems with WebSAINT, which is a web based tool that uses SAINT.

From the notice at the bottom of netsaint.org: NetSaint is not affiliated with World Wide Digital Security, Inc. (WWDSI); Richard S. Carson and Associates, Inc; and the marks WEB SAINT, SAINT, SAINTWRITER, SAINTEXPRESS, and SAINTBASIC owned by Richard S. Carson and Associates, Inc.

And I may as well mention that Nagios/Netsaint is a really great tool and I highly recommend it. It won't, however, keep you up to date on "suspicious" activity - it's mostly for just making sure that your server and any services that run on it are going.

Re:Nagios

[PerryMason]

It won't, however, keep you up to date on "suspicious" activity - it's mostly for just making sure that your server and any services that run on it are going.

Well actually it _can_ keep you up to date on 'suspicious activity' if you are willing to write a plugin to say, monitor your IDS output.

Nagios itself is nothing more than a web-based system of notification. The plugins provide whatever functionality you code into them, from monitoring a network service, to parsing a logfile, to monitoring temperature. Pretty much anything that provides you with feedback can be used as the input to a plugin.

I actually wrote a little plugin that parses the output from my Win2k Terminal Server logs (via BackLogNT) on my central syslog server to email me everytime my boss logs on and logs off from Windows so I can figure out when he is leaving home and on his way into the office.....and he has yet to catch me playing games when I should be working. :)

The long and the short is that Nagios handles the notifications, the plugins handle what is being measured/monitored.

Orca

[geog33k]

I use Orca (but then I'm its author :) ) to monitor Solaris and Linux boxes. I used it at Yahoo!/GeoCities to monitor 200 boxes and it was easy to see when systems were doing odd stuff.

Sample Solaris and Linux plots. The Solaris version shows a whole ton of web server stats.

Lots of stuff

[vadim_t]

logcheck will mail you about unusual stuff that appears in log files.

monit will monitor running damons and can restart them if they crash, use too much CPU/RAM, etc, mailing about anything interesting.

tripwire or lire are nice for monitoring filesystem integrity, but these tools aren't easy to use. The database they use must not be located in a safe place, which can make them impractical.

I think the best thing would be doing all logging to a safe computer that only runs the logging daemon, so that you can be sure you're not missing anything.

Red Hat Comes with Logwatch

[man1ed]

Logwatch is a pretty decent system. I comes with Red Hat (and probably other distributions as well) and mails you a summary of the system log. The main thing I use it for is to keep track of what IPs are connecting to which services how many times.

Re:User of the word boxen

[quiddity]

I tend towards pedantic nitpickering on the occasion also, but it's good to bare in mind that playing [to destruction!] with language is both edumacational and amusin'.

i like "boxen" for the same intriguing subcultural contexts as i like "w00t" and "geek".

remain happily hypocritical :)

Adminux

[jkidd]

Have you looked at http://www.adminux.com It does security monitoring, error monitoring, performance monitoring. Cross platform support. It does cost... I used it to monitor 50 HP-UX boxes, 30 AIX boxes, some Suns, and Linux systms.

I rolled my own

[MarkusQ]

I rolled my own, mostly in Ruby (and ran it in parallel with the previous solution for several months). The main reason? I wanted to know about the things I wanted to know about, and not have to dig the information out of a lot of other cruft. So I do a lot of filtering to supress details that fall within what I define as "normal" for my setup, and only report the exceptions.

The main benifit of this turned out to be that I learned a lot about a configuration that I thought I knew inside and out. Yes, it was more work than dropping in a ready made package, but in retrospect it was well worth it.

-- MarkusQ

monitoring, no one size fits all

[perlchild]

owing to the fact almost no product will fit everyone's needs

here are aspects where you can compare what you will find

aspects of monitoring:
-availability
-uptime(subtly different from availability)
-performance
-security
-capacity
-log or otherwise event-based monitoring

nature of tools:
-web based
-daemon with web based front end
-daemon without web based front end
-other

language tool is written in, license and source
-closed source, nuff said, available in licensed per cpu, licensed per target/service, etc...
-open source, but with paid-for license that includes support(shameless plug... I do support for this kinda thing)
-open source, roll your own support
-perl
-php
-java
-python
-c/c++

integration with other products
-by snmp traps
-by snmp agent extensibility(smux/agentx/proxysnmp,etc...)
-by proprietary methods
-by sharing a RDBMS with another monitoring tool(usually used for things like remedy ARS)

measure of performance/capacity/throughput/usage
-by the exec family of functions
-by the language of choice's own internal library conventions
-by snmp
-by proprietary methods to a Manager of Manager or NMS system
-by ciscoflow/other hardware vendor's protocol
-by parsing logs
-by exec-over-ssh-connexion

examples that don't fit neatly into any category that comes to mind is monitoring of backups(were they performed, how much, which files were skipped, etc, location in jukebox of which tape for which file...

Hope this helps you even draw the lines towards evaluating the product that meets YOUR needs

Palantir

[hkon]

Palantir kan be found at www.netsonde.com. It's a system not entirely unlike Nagios, written mostly in Perl. Works with all the unix-like OSs I can think of in addition to Windows.

Re:syslogd?

[unixbob]

you need a central syslog server. Syslogd can automatically send it's logs to a central syslog server using udp. Just look in your syslog.conf.

We've got a nifty setup where we have syslog-ng running on our central syslog server. syslog-ng then squirts the data directly into a MySQL database. We've then got a custom PHP interface which sorts the errors by severity and colour codes them so we can always see what is going on. Our switches write to it. Our nokia firewalls write to it. Even the F5 load balancers and the Network Applicance NAS systems. It's so useful that we have installed ntsyslog onto our win2k servers so that all the info is in one place.

my 2 lines of perl...

[Smoking]

I had good experience with the following tools: cacti
It's based on RRD the successor of MRTG (not much developed anymore, but still a good tool). Thanks Tobi btw.
OpenNMS is a really powerful realtime monitoring tool
Nagios also...
Don't forget snort for your IDS needs and add acidlab for good visualization of snort's results.

Re:User of the word boxen

[david duncan scott]

I could be wrong here, but I think there is a history involved. Back in the day, there was no good plural for "VAX", and many DEC people started referring to "VAXen" (these were, after all, the same people who often called themselves "VAXherds".) I believe "boxen" to be derived from "VAXen", and as such I find it has a certain old-fashioned charm.

Cacti

[jdurham]

I've been extremely impressed with Cacti for statistic monitoring. It can be found at: http://www.raxnet.net/products/cacti/ It's quite easy to set up, and for larger sites, it has an excellent user privilege system.

Re:User of the word boxen

[br0ken2o0o]

I guess I will bite....

Whenever someone uses that word to me i turn around and stop listening to them, it really makes me question there inteligence both in the IT field and in general inteligence.

Perhaps we should turn around and stop listining now....

Josh

gkrellm

[dooby]

is what I like to use for monitoring real-time stuff - like if my network traffic suddenly rockets, or memory is disappearing.

It's skinnable, configurable and supports plugins. I've seen it working on Solaris and Linux, YMMV. It's here (with screenshots).