Merlin is MySQL’s Enterprise Monitor, a system designed to monitor a number of MySQL database servers and provide useful feedback to the DBAs as to how they are running and what things may require attention.

It provides various things:

• graphs of key database and server performance indicators: load average, cpu usage and mysql specific information such as number of database connections, replication delays, buffer usage statistics, etc…
• a set of advisors which are intended to tell you if things are not configured properly and what to do to correct the problem.
• monitoring of servers which are linked together through replication
• the latest version of merlin (v2.0, which has been available since the beginning of the year) additionally adds via mysql proxy the ability to see all the queries which are …

Giving a bunch of mysql instances something you do everyday and you might think ….. how should I do it? Write a bunch of selects and inserts manually? nahh that takes s**tload of time, should I run binlogs collected from a live system on my test server? nahh thats not practical nor is it real since it doesn’t contain selects, should I gather the general query log and try that out? nahhh  …..

MySQL has been kind enough to supply us with their mysql_slap which does the job for us and given I needed to do a proof of concept on monitoring a group of 4 circular replicated servers I wrote a small script which does the job of slapping them with a varying level of concurrancy, iterations, number of queries and connections for as long as you like.

Here it is and I hope some of you might find it useful for slapping their own test servers :).

#!/bin/bash

NumberOfConcurrentLoads=4
…

It’s been a while since I’ve sent any news about the MySQL Cacti Templates project I started a while ago. Here’s what’s new:

First of all, it’s not just MySQL templates anymore. It’s a generic framework and tools for creating templates, and I’ve written templates for Apache, Memcached, etc. I just haven’t publicized [...]

Since a few months we are monitoring our infrastructure at Days of Wonder with OpenNMS. Until this afternoon we were running the beta/final candidate version 1.5.93.

We are monitoring a few things with the JDBC Stored Procedure Poller, which is really great to monitor complex business operations without writing remote or GP scripts.

Unfortunately the migration to OpenNMS 1.6.1 led me to discover that the JDBC Stored Procedure poller was not working anymore, crashing with a NullPointerException in the MySQL JDBC Driver while trying to fetch the output parameter.

In fact it turned out I was plain wrong. I was using a MySQL PROCEDURE:

DELIMITER //
CREATE PROCEDURE `check_for_something`()
READS SQL DATA
BEGIN
SELECT …

Monolith: MySQL server monitoring. I only have servers that run Redhat/Debian/Ubuntu Linux x86 and x86_64. I don’t have machines to test MySQL monitoring for the following OSes. Perhaps you would like to be a test candidate for the new version of Monolith? If so, let me know and you’ll be on the list, as well as get beta testing credit.

OSX Server: PPC and Intel

AIX

FreeBSD / OpenBSD / NetBSD

Windows Server

Solaris: Intel & Sparc

Linux servers that are NOT Intel based.

What this involves: testing the client script, perl modules, snmp stats, and other functions that may require a custom client script for that architecture.

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 [...]