The latest from the MySQL community

In part 2 we discussed the internals of MPP and how MPP can be used with LVS to create a failover strategy. In this part 3 we will discuss how to configure and operate MPP, and additionally use MPP with MySQL Proxy to create a failover strategy.

Today's entry is provided by Ben Ramsey.

Name

Ben Ramsey

Blog

benramsey.com

Biography

Ben Ramsey is a software architect at Schematic and the founder of the Atlanta PHP user group. He is the co-author of php|architect's Zend PHP 5 Certification Study Guide. He also spends way too much time in #phpc.

Location

Atlanta, Georgia

I frequently receive email messages, am asked at conferences or Atlanta PHP meetings, or am approached on IRC about how one can get involved in the PHP community. Being involved means different things to different people. Some …

I was just poking around the Open Solaris site looking for an Intel install (all of the Suns I have are Sparc based).

And what happens to be on the front page?

A note saying they will ship you a DVD with a couple of Solaris distributions.

http://www.opensolaris.org/os/

It will save me the download, and it means I can try out a couple of Solaris distributions. This has been on my list to do since I want to extend the DTrace support I added to MySQL 6.0, and being able to do this from my laptop would make the process a lot easier.

I just checked Amazon.com now and they do not have a book on DBA for Dummies. This was not surprising to me as I know that there are only a handful of DBAs out there specifically for MySQL.

And what topics would be covered in this book? Replication, backups, security, etc... But all of these topics can be found in other MySQL books. So, why would someone write a book for DBA for Dummies? Because it would contain advance topics or a in-depth details on the topics just mentioned. For example, how do you do circular replication? Or how do you manage 25 databases?

At Flickr we use a Federated Architecture, where the WHOLE of the data is spread across many servers. This means that when you load a photo page the dynamic data generated is hitting a server that holds that data, while another photo page view may hit another server for content.

Now to do complex operations to control the flow of what operates on data, the complex operation must lock the data. Let's call this a global lock, which is used to coordinate many jobs. Now to make these operations fast, lets run many processes across many servers. Essentially we needed to solve a hard problem in parallel computing: distributed locking.

This took a bunch of dedicated time to get done properly. We solved the issue by using 3 database clusters.

First I used the coolest mysql feature out there; GET_LOCK and IS_FREE_LOCK. These two mysql function are the heart of the distributed lock.

Why use them …

phpsh requires readline support built into python. It also requires python version 2.4+. You can check which version of python you have installed by typing: python -V Let us download and install readline: wget ftp://ftp.cwru.edu/pub/bash/readline-5.2.tar.gz tar zxf readline-5.2.tar.gz cd readline-5.2 ./configure make install Now let us install python with readline support:

wget http://www.python.org/ftp/python/2.5.1/Python-2.5.1.tgz tar zxf Python-2.5.1.tgz cd Python-2.5.1

I had some problems on one of the [...] …

Times of change are upon the database market. The major established database companies are being challenged by open source upstarts like MySQL and PostgreSQL. For years, Open Source Databases (OSDBs) have been quietly increasing their penetration, but until recently they have lacked the capabilities to seriously threaten proprietary databases like Oracle, IBM's DB2, and Microsoft's SQL Server.

All that has changed. OSDBs now boast the necessary features and robustness to support commercial databases hundreds of Gigabytes in size. And a growing trickle of competitive benchmark results shows them …

Here's the replication structure: 1 master, 5 slaves under it, each slaves have another 5 slaves under it.

Here's the problem: What if you have to update a couple of big tables and you know that if you apply it to the master that it will take a long time to replicate? What can you do?

Here's the solution: Run the update queries on each database by turning off replication. This can be done by running the command below.

set SQL_LOG_BIN = 0;

1. Check if all the weekend database related jobs ran, this could be backup, or some data-related processing work.

2. Check your replication and make sure it was running smoothly (you should actually check this everyday).

3. Check your logs for any related errors.

4. Check the scripts that you are working on.

Times of change are upon the database market. The major established database companies are being challenged by open source upstarts like MySQL and PostgreSQL. For years, Open Source Databases (OSDBs) have been quietly increasing their penetration, but until recently they have lacked the capabilities to seriously threaten proprietary databases like Oracle, IBM's DB2, and Microsoft's SQL Server.

All that has changed. OSDBs now boast the necessary features and robustness to support commercial databases hundreds of Gigabytes in size. And a growing trickle of competitive benchmark results shows them …