Yesterday, I needed to determine the runtime of a Linux process for a monitoring script.

Cos the format for start_time of the ps command may change if the process was not started in the same year, I decided to take the neccessary informations from the /proc/<PID>/stat file.

In this file the process start time since boot is defined at the twenty-second field, expressed in Jiffies – the scale unit of the system timer. (One Jiffie is one tick of the system timer).

To convert Jiffies to seconds I just have to divide the number of Jiffies by the frequency (hertz) of the system timer, which is defined in the Linux Kernel header file include/asm-generic/param.h. The frequency may differ between Linux kernel versions and hardware platform! On my Linux systems the frequency is 100 HZ.

In a shell script the following line will …

If you're using MySQL replication, then you're probably counting on it for some fairly important need. Monitoring via something like Nagios is generally considered a best practice. This article assumes you've already got your Nagios server setup and your intention is to add a Ubuntu 10.04 NRPE client. This article also assumes the Ubuntu 10.04 NRPE client is your MySQL replication master, not the slave. The OS of the slave does not matter.

Getting the Nagios NRPE client setup on Ubuntu 10.04

At first it wasn't clear what packages would be appropriate packages to install. I was initially misled by the naming of the nrpe package, but I found the correct packages to be:

sudo apt-get install nagios-nrpe-server nagios-plugins

The NRPE configuration is stored in /etc/nagios/nrpe.cfg, while the plugins are installed in /usr/lib/nagios/plugins/ (or lib64). The installation of this package …

Regardless of the monitoring tool you use to monitor your databases, it can be better to monitor this tool.
No, it’s not a joke ! Do you think you can have a benefit with a monitoring tool not connected to your servers ? ( without being alerted )

I choose to talk about MONyog here but this can apply to all existing monitoring tools.
I just want to share the message, the tool does not matter, so, do it !

So, let me explain how to control if you have fresh data with MONyog.
With MONyog it’s easy because it’s an agentless monitoring tool.

There are two ways to check that :

Per server general info :

For each server, you can …

In this tutorial I will describe, how to use nmon (Nigel’s performance Monitor) to monitor performance data in the interactive mode or in the capture mode.

nmon can display / capture the following performance data

• CPU utilization
• Memory use
• Kernel statistics and run queue
• Disks I/O rates, transfers, and read/write ratios
• File systems size and free space
• Disk adapters
• Network I/O rates, transfers, and read/write ratios
• Paging space and paging rates
• Machine details, CPU and OS specification
• Top processors
• User defined disk groups
• Asynchronous I/O – AIX only
• Workload Manager – AIX only
• ESS and other disk subsystem – AIX only
• Dynamic LPAR changes …

Back in February I wrote an article titled A Small Fix For mysql-agent. Since then we did a few more fixes to the agent and included a Bytes Behind Master (or BBM) chart. For those who can't wait to get their hands on the code, here's the current version: MySQL SNMP agent RPM. For those who'd like to learn about it's capabilities and issues, keep reading.

What to Expect From this Version
The article I quoted above pretty much describes the main differences with the original project, but we went further with the changes while still relying on Masterzen's code for the data collection piece.

The first big change is that we transformed Masterzen's code into a Perl module, …

We make a lot of posts that give IT tips and advice, as well as recommendations on how to use Monitis, so here is a summary of the posts for this week in case you missed them.

Monitoring IIS With VBScript via Monitis; It’s so Easy!

This post demonstrates how to monitor an IIS using Monitis Custom Monitors and VBscript. You can use the Monitis API to monitor your own custom metrics. This is very powerful because it lets you monitor any IIS metrics you like, set thresholds and receive notifications.

Top 4 Software Based IIS Server Performance Tips

These 4 …

I bring this up because of recent conversations I have found myself in.

Over the years I have gone back and forth between OSX & Linux laptops. Over these same years I was also monitoring several MySQL databases. I have found numerous server side solutions for you to be able to monitor your database, Nagios and of course MySQL Enterprise Monitor to list a couple. Both of these are great solutions and allow you to try and get some sleep and night.
Years ago, while using OS X, I was enlightened to learn about a free module called Geektool, it is not new, but I often find people are unaware of it.  I have had at least three conversations about it lately. While Nagios …

Listening to the OurSQL podcast: Repli-cans and Repli-can’ts got me thinking, what are the issues with MySQL replication that Sarah and Sheeri didn’t have the time to include in their episode. Here’s my list:
Replication Capacity Index This is a concept introduced by Percona in last year’s post: Estimating Replication Capacity which I revisited briefly during my presentation at this year’s MySQL Users Conference. Why is this important? Very …

I saw that both Haidong Ji and Geert VanderKelen have proposed a Python monitor for MySQL replication, calling it the "poor man's version".
See Poor man’s MySQL replication monitoring and Geert's Refactored: Poor man’s MySQL replication monitoring.
Having Python in your server doesn't really qualify as "poor man". In many cases it's a luxury, and thus, here's my shot at the problem, using a Bash shell script.
Unlike its Python-based competition, this version also checks that the slave is replicating from the intended master, and that it is not lagging behind.

#!/bin/bash

USERNAME=msandbox
PASSWORD=msandbox
EXPECTED_MASTER_HOST=127.0.0.1
EXPECTED_MASTER_PORT=27371

SLAVE_HOST=127.0.0.1 …

In a project Severalnines is engaged in, we are developing a realtime application based on Cluster/J. To start with, I must say cluster/j is fantastic and so far I am very happy with it and beaten our expectations big time. It is quite new however and we stumbled on a couple of issues, but those were fixed very fast by the Cluster/J developers. The bugs we encountered were:

• bug 59942
• bug 59941
  

Both which were worked around, and really we never did need to have a binary or a varbinary as the PK, we used a

Performance is great - we have two data nodes (nehalem, 32GB RAM, 146GB SAS 10K disk, 2x4 core 2.4GHz (E5620) ) and two application hosts (same spec, less RAM as data …