Server Monitoring With munin And monit On CentOS 5.2

In this article I will describe how you can monitor your CentOS 5.2 server with munin and monit. munin produces nifty little graphics about nearly every aspect of your server (load average, memory usage, CPU usage, MySQL throughput, eth0 traffic, etc.) without much configuration, whereas monit checks the availability of services like Apache, MySQL, Postfix and takes the appropriate action such as a restart if it finds a service is not behaving as expected. The combination of the two gives you full monitoring: graphics that lets you recognize current or upcoming problems (like "We need a bigger server soon, our load average is increasing rapidly."), and a watchdog that ensures the availability of the monitored services.

There are all sorts of different interfaces to memcached, but you don't need any of them to make requests from the command line, because its protocol is so simple. Try this, assuming it's running on the usual port on the local machine:

PLAIN TEXT CODE:

1. echo stats | nc 127.0.0.1 11211
2. STAT pid 22020
3. STAT uptime 3689364
4. STAT time 1227753109
5. STAT version 1.2.5
6. STAT pointer_size 64
7. STAT rusage_user 4543.071348
8. STAT rusage_system 8568.293421
9. STAT curr_items 139897
10. STAT total_items 51710845
11. STAT bytes 360147055
12. STAT curr_connections 40
13. STAT total_connections 66762
14. STAT connection_structures 327
15. STAT cmd_get 319992973
16. STAT cmd_set …

Progress on the Open Source enterprise grade MySQL monitoring system;  the schema for Monolith version 2 has been designed. Due to the many suggestions for features and the interest it has received I’ve put this on the front burner. That said, here is some more info on the next steps I’ll be taking.

• Monitored servers will use a command line agent (called remotely) to pull information from both MySQL and the OS.
• Historical information will include all values from global status and global variables, as well as CPU/Memory/IO/Disk usage.
• Standard graphing functions - the ones in the list from the previous post - will gather information from various view tables that contain historical data that is collected from the agent script. User defined graphing will allow you to look at historical values over time for any of the various global status or global variable settings (integer based ones anyway). …

What would you like to see in a free enterprise-grade monitoring system for your daily MySQL needs?I’m rewriting Monolith - MySQL DBA Console from the ground up. This will be version 2 and I would like to get some input from the global MySQL community.So far I am going with the following; comment with any improvements/additions.

• Variable interval polling of server statistics
• Over 50 different alerts (see list below)
• Graphing of various server statistics (see list below)
• Tuning recommendations with cnf file changes to apply to server
• Change control documents for recommended performance/security tuning
• Threshold based alerting with multiple alert groups: info,warn,critical
• Sorting/ordering of servers via groups. ie: client -> dev,stage,prod
• RSS feeds for each alert group
• XML export with user defined fields for external applications …

I’ve released version 1.1.1 of the MySQL Cacti templates I develop. The new templates work around more Cacti limitations, including the limitation on the length of the data returned from the poller script. There’s also a new graph and many other niceties since the last release.

Note that there are TWO incompatible changes with [...]

It’s been a while since my last post! I have a few half-written entries, but I figured I just get one out there so I don’t appear to have dropped off the face of the planet

Being more of a DBA than a sysadmin myself, I’ve noticed that there is a surprising dearth of information regarding how to actually get nagios set up to monitor MySQL, especially if you’re not experienced with nagios.

In my own experience, MySQL monitoring often ends up being a homegrown thing, especially if you’re a small shop. It is definitely a good idea to consolidate all of your monitoring, DB-related or not, into one solution: roll-your-own monitoring solutions can be brittle and burn you in the end. One example that comes to mind, a few years back i had a quick perl-based script to monitor replication and set it to mail a few people based on some threshold. Took me 1 hour to write and worked well enough, except, six months later, when some …

To be fair - I highly doubt it has anything to do with MySQL.Database corruption - that's a different issue, often related to a bug in database code; but this was a data corruption issue, which is always a pain in the you know what to figure out and get fixed.I spent the last day trying to figure out the weirdness in a couple of our databases, digging around, explaining to developers that

As mentioned earlier , Packt sent me their Zenos Core Network and Systems Monitoring by Michael Badger to review.

So I spend the past couple of weeks trying to crawl my way trough it. Not that there was any problem with the book, more with my schedule :) I was hoping to finish it some time ago but time was working against me, even last week when my flight back from Zurich was a bit shorter than planned I couldn't finish reading the book.

But yesterday I managed, Michael managed to write a good book on a hot topic during what was probably one of the most busy of his life.

In 8 chapters Michael manages to explain the different aspects of Zenoss fairly well, he …

Hartmut rules!It started during …

Baron posted something interesting about agent vs agent-less monitoring in response to Rob.

While reading it, I couldn’t help thinking that the distinction is somewhat misleading, if not wrong.

I’d go so far as to say that agent-less doesn’t exist as such. Why do I say such heresy?

Trivially, you need some piece of software to collect data. With munin you configure a server that triggers scripts on the monitored servers. The set of data sources is governed by what you install in the correct directory on the monitored server. Cacti relies on SNMP heavily and also …