MySQL Enterprise Monitor is a tool to watch and analyze multiple MySQL environments from a single web based dashboard. More information is available on the MySQL homepage. Each MySQL instance is monitored by a small agent that connects to the MySQL instance and reads statistics that is sent to the MySQL Enterprise Monitor (MEM) Server.That setup is very easy. But if the MySQL server is in a cluster failover configuration, there are some things to consider when installing the MEM agent:

What do you want?

Do you want to have two entries in the MEM dashboard for both physical servers?This is good because: …

The goal is to have only one entry in the Enterprise Monitor Dashboard that shows the status of the MySQL instance, no matter on which physical server in runs. There are two ways to achieve this:

• You can install the agent on both physical nodes
• You can install the agent on a shared storage.

In either case you have to make sure, that only one agent runs at a time. You have to integrate the agent into your cluster framework. I will not describe how this works, as it is highly dependant on your cluster framework.
The following description assumes, that you will install the agent on both physical nodes.

1. Install the agent but DO NOT START the agent yet.
   
   
2. Edit the [agent-installdir]/etc/mysql-monitor-agent.ini
   In the [mysql-proxy] section add the following line:
   agent-host-id=[logical hostname]
3. …

The 169th edition of Log Buffer, the weekly review of database blogs, has been published on Pakistan’s First Oracle Blog by Fahd Mirza.

This is the first Log Buffer published outside Pythian in quite a while, and we’d love to have more. Log Buffer has a regular readership, and so makes a great way to present yourself and your blog to the DBA community at large. To get started, just send an email to the Log Buffer coordinator.

And now, here is Log Buffer #169.

A can do method to consolidate table spaces without a full dump out and reload is to use cat. At first I did not think this would work in all cases, and am still not certain for ALL cases; however, I set up a quick and easy test just to see.

Example 1 below shows how to create a test table, create a multi-line insert file then insert the data. From there I shutdown MySQL cat the 4 table spaces into one file and restart MySQL.

-- Example 1

Table space allocation:
innodb_data_file_path=data001:128M; data002:128M; data003:128M; data004:128M

mysql> CREATE TABLE `tbl1` (
`anum` int(11) DEFAULT NULL,
`blah` varchar(255) DEFAULT 'BLAHblahBLAHblah'
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

shell> file=mass_insert2.sql; echo "insert into test.tbl1 (anum) VALUES " >> $file; for x in $(seq 0 100000); do if [ ${x} -eq 0 ]; then …

Symbian’s future in the balance? All Go for Chrome OS. And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

Symbian’s future in the balance?
The H reported that Samsung is to abandon Symbian in favour of Windows Mobile, Android and the new Samsung bada OS, while Samsung later denied that …

Installing Apache2 With PHP5 And MySQL Support On Mandriva 2009.1 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a Mandriva 2009.1 server with PHP5 support (mod_php) and MySQL support.

To install the MEM agent in a way that both physical servers are listed in the MEM dashboard, you have to install the agent on both physical nodes. But: Do not start the agent after the installation!There are three different IDs in MEM: agent-uuid, mysql-uuid and host-id. Usually they are generated automatically and you will never notice these IDs. For more information about the meaning of the different IDs look at this very good explanation from Jonathon Coombes.The agent stores the uuid and the hostid in a MySQL table called mysql.inventory. After a failover the other agent on the new node will notice "wrong" hostid and uuid entries in the inventory table. The agent will stop and ask you to TRUNCATE mysql.inventory. But with this procedure MEM creates a new instance, so all old data is lost. Not good for a failover environment.So in case of a …

Our performance tuning guide is now available at infinidb.org.  Subjects touched on  include:
  How are hash joins implemented with InfiniDB?    How is work parallelized across multiple cores, and optionally multiple servers? 
  What "rules of thumb" change with InfiniDB's column storage?
  What is the fastest way to load data with InfiniDB?  
  What is a Batch Primitive Step (BPS)?  

- JRead More...

The recording and slides from this week’s MySQL Cluster Geographic Replication webinar is now available – download replay & slides. As always the material is free.

MySQL Cluster Replication

For those that missed the invitation, here is a description of the content…

MySQL Cluster has been deployed into some of the most demanding web, telecoms and enterprise / government workloads, supporting 99.999% availability with real time performance and linear write scalability.

Tune into this webinar where you can hear from the MySQL Cluster product management team provide a detailed “deep dive” into one of MySQL Cluster’s key capabilities – Geographic Replication.

In this …

Yesterday's MySQL University session on Gearman for MySQL had a rough start. After I had assigned Giuseppe presenter status we found out that Dimdim (our conferencing system) now turns on video when it discovers a web cam on the presenter's computer. That's not a bad thing in general, but you can't turn it off, which *is* a bad thing when your network bandwidth is less than superior. As a consequence, Giuseppe's voice came over very choppy, and the presentation stopped altogether after a few minutes.

For that reason, we decided to restart the session from scratch. This time Giuseppe turned off his camera before becoming presenter, and the session worked flawlessly. For those of you who've given up because of bad sound quality, the recording is here, and it looks and sounds good. You can find it on the MySQL University session page: …