Databases, Systems & Networks

Source: unixmen.com

Introduction

You have a problem while monitoring your servers, switches or physical machines. Observium fits your need. As a free monitoring system, it helps you to monitor your servers remotely. It is an auto-discovering SNMP based network monitoring platform written in PHP which includes support for a wide range of network hardware and operating systems including Cisco, Windows, Linux, HP, NetApp and many other. I will give you the steps to follow while setting up an Observium server on Ubuntu 12.04.

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You have configured your MySql replication, next step is to perform maintenance and monitor your replication. Percona Toolkit for MySQL is a collection of advanced command-line tools to perform a variety of MySQL server and system tasks.

The Percona Toolkit allows you to amongst many tasks to verify MySQL replication integrity, efficiently archive rows, find duplicate indexes, summarize MySQL servers, analyze queries from logs and tcpdump, collect vital system information when problems occur.

To get started you need to install Percona Toolkit, I’m using Ubuntu as an OS on my servers, installing the percona toolkit was straight forward

apt-get install percona-toolkit

To get a summary of your databases use the command – pt-mysql-summary

pt-mysql-summary --u=username --p=password

Next you would want to setup a heartbeat table in your database so you can Monitor MySQL replication delay – for that you will use the pt-heartbeat command.

pt-heartbeat -D wpslavedb --create-table --ask-pass --check --master-server-id 1

You can find the manual for the options here.

pt-heartbeat measures replication lag on a MySQL or PostgreSQL server. You can use it to update a master or monitor a replica. mk-heartbeat depends only on the heartbeat record being replicated to the slave, so it works regardless of the replication mechanism. It works at any depth in the replication hierarchy; for example, it will reliably report how far a slave lags its master’s master’s master.

Start daemonized process to update test.heartbeat table on master:

  pt-heartbeat -D wpslavedb --update -h master-server --daemonize --ask-pass

Monitor replication lag on slave:

  pt-heartbeat -D wpslavedb --monitor -h slave-server --ask-pass
  pt-heartbeat -D wpslavedb --monitor -h slave-server --dbi-driver Pg --ask-pass

Check slave lag once and exit (using optional DSN to specify slave host):

  pt-heartbeat -D wpslavedb --check h=slave-server --ask-pass

If the replication hierarchy is “master -> slave1 -> slave2” with corresponding server IDs 1, 2 and 3, you can:

  pt-heartbeat --daemonize -D wpslavedb --update -h master --ask-pass
  pt-heartbeat --daemonize -D wpslavedb --update -h slave1 --ask-pass

Then check (or monitor) the replication delay from master to slave2:

  pt-heartbeat -D wpslavedb --master-server-id 1 --check slave2 --ask-pass

Or check the replication delay from slave1 to slave2:

  pt-heartbeat -D wpslavedb --master-server-id 2 --check slave2 --ask-pass

if you developing and writing SQL statements, this command is very useful pt-query-digest – Analyze MySQL queries from logs, processlist, and tcpdump

  pt-query-digest slow.log    // requires you to have slow query logged enabled

There are other tools Percona Toolkit, these that I shown is what I find useful for my monitoring and maintenance.

If you want to find out the best MySQL configuration for your application, you can head over to Percona’s website they have a MySql wizards.

Source: torbjornzetterlund.com

Need to monitor Linux server performance? Try these built-in command and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as:

1. Finding out bottlenecks.
2. Disk (storage) bottlenecks.
3. CPU and memory bottlenecks.
4. Network bottlenecks.

#1: top – Process Activity Command

The top program provides a dynamic real-time view of a running system i.e. actual process activity. By default, it displays the most CPU-intensive tasks running on the server and updates the list every five seconds.

Commonly Used Hot Keys

The top command provides several useful hot keys:

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Pour faire le monitoring du port 3306 sous Linux il suffit d’utiliser la commande :

tcpdump  -i eth0 -nN -vvv -xX  -s 1500  port 3306

Où s représente la longueur du paquet.