In response to a number of comments, I thought I would clarify the scope of my discussion regarding Options using MySQL pairs before I begin. As mentioned their is no one way or type of configuration for MySQL in a HA solution, however the simplest progression from a single Master/Slave environment is the concept of a pair of servers, configured to support a fail over and fail back via MySQL Replication.

The concept of a MySQL Pair in this context is to have a “hot” MySQL standby ready for controlled and hopefully! automated fail over. I say hopefully because with MySQL Replication as an asynchronous solution there is no guarantee for no loss of data.

I consider DRBD/Heatbeat for example a “cold” standby, as MySQL on the slave server is not actually running. DRBD does provide …

Configuring a production environment using a pair of MySQL servers in a Master/Fail Over Master situation is a common process to provide many benefits including supporting failover, backup/recovery, higher availability for software & database upgrades. This is also a common method for database shards. One of the key hidden benefits is by performing regular controlled failovers for example with software upgrades you are actively testing your disaster recovery procedures. Most organizations have a partial plan, some don’t have any, but rarely do people test their disaster recovery.

There is no one way to configure and manage such an environment. There are a number of options including:

• Develop your own home grown scripts
• Flipper by Proven Scaling
• …

The 2009 MySQL Conference has closed it’s submissions for papers. This year the motto is “Innovation Everywhere”.

Last weekend’s Open SQL Camp in Charlottesville, Virginia, we had the chance to talk about the movements in the MySQL ecosystem. I was impressed to get the details of the Percona MySQL Patches, but focus is still in 5.0. (Welcome to the Percona team Tom Basil) Our Delta is attempting now to integrate patches into various MySQL branches. There was an opening keynote by Brian Aker from Drizzle, and Drizzle team Jay Pipes and Stewart Smith on hand. It was also announced that MySQL 5.1.30 will be GA, available in early December.

But these …

I had this perplexing problem yesterday where a mysql dump and restore was producing different results when using MaatKit mk-table-checksum.

mk-table-checksum --algorithm=BIT_XOR h=192.168.X.XX,u=user,p=password --databases=db1 --tables=c
DATABASE TABLE   CHUNK HOST         ENGINE      COUNT         CHECKSUM TIME WAIT STAT  LAG
db1      c           0 192.168.X.XX InnoDB     215169         d1d52a31    2    0 NULL NULL
mk-table-checksum --algorithm=BIT_XOR h=localhost,u=user,p=password --databases=db1 --tables=c
DATABASE TABLE   CHUNK HOST      ENGINE      COUNT         CHECKSUM TIME WAIT STAT  LAG
db1      c           0 localhost InnoDB     215169         91e7f182    0    0 NULL NULL

It was rather crazy until I reviewed the mysqldump settings I was using, and I realized I was using –no-set-names.

So just what does this option remove. Here is a diff of mysqldump with and without.

We all know with MySQL you can use ORDER BY with a list of columns to return an ordered set, e.g. ORDER BY name, type, state;
I often use the syntax ORDER BY 1,2; which I’m surprised that some people do not know about.

However I needed to do some selective ordering of a type field, I didn’t want to for example have a lookup table just to join for ordering. While contemplating a means of achieving this, I asked a work colleague, who I figured may have just experienced this problem before. Lone behold I became the student as I discovered there is a third syntax with ORDER BY, using expressions.

mysql> create table test(name varchar(10) not null, type varchar(10) not null);
Query OK, 0 rows affected (0.06 sec)

mysql> insert into test(name,type) values
('Apples','Fruit'),
('Bananas','Fruit'),
('Carrots','Veg'),
('Onions','Veg'),
('Beer','Liquid'),
('Water','Liquid'),
('Crackers','Food');
Query OK, 7 rows affected (0.00 sec) …

The current US financial situation has claimed a victim in the Web 2.0 world — Uber. I’m not sure if this is the first significant name, but it will not be the last site running MySQL where investors will be quick to cut losses and move on.

So… A few years back I spent a LOT of time with Oracle ETL and BI products. I learned them inside and out, gave some user conference presentations, wrote a bunch of blogs, even Alpha tested a version of Oracle Warehouse Builder. Then I found “Open Source BI” and I’ve been heading breakneck into the world of MySQL, Pentaho, … A choice I do NOT regret - my consultancy is busier than ever and I love the Open Source BI play.

However - I miss seeing some of the old Oracle peeps at Open World. This year, I even registered for my free ACE pass to OOW but didn’t make it because I started two new projects this week. What I realized this year, was that I’m WAY out of touch with what’s going on in the land of Big Red O. The words and products for BI whiz past me - they don’t even look anything like they did just a couple of years back.

I hope everyone had a good time at OOW this year! I don’t see a path back to the land of …

Indexes are a great way to improve performed in a MySQL database, when used appropriately.
When used in-appropriately the impact can be a degradation of performance.

The following example from Movable Type shows how when reviewing the slow query log I found numerous occurrences of Inserts take 3 or more seconds, with no reported lock contention time for this insert.

# Query_time: 3  Lock_time: 0  Rows_sent: 0  Rows_examined: 0
SET insert_id=6281;
INSERT INTO mt_comment
(comment_author, comment_blog_id, comment_commenter_id, comment_created_by,
 comment_created_on, comment_email, comment_entry_id, comment_ip, comment_junk_log,
comment_junk_score, comment_junk_status, comment_last_moved_on, comment_modified_by,
comment_modified_on, comment_parent_id, comment_text, comment_url, comment_visible)
VALUES (...)

The impact here, is that SELECT statements to the mt_comment table …

Why you do not use GRANT ALL ON *.*?

I was with a client today, and after rebooting a MySQL 5.0.22 instance cleanly with /etc/init.d/mysqld service, I observed the following error, because you always check the log file after starting MySQL.

080923 16:16:24  InnoDB: Started; log sequence number 0 406173600
080923 16:16:24 [Note] /usr/libexec/mysqld: ready for connections.
Version: ‘5.0.22-log’  socket: ‘/var/lib/mysql/mysql.sock’  port: 3306  Source distribution
080923 16:16:24 [ERROR] /usr/libexec/mysqld: Table ‘./schema_name/table_name’ is marked as crashed and should be repaired
080923 16:16:24 [Warning] Checking table:   ‘./schema_name/table_name’

Now, I’d just added to the /etc/my.cnf a number of settings including:

myisam_recovery=FORCE,BACKUP

which explains the last line of the log file. When attempting to connect to the server via the mysql client I got …

Do you have a full time System Administrator? Do you have only a part-time SA, or none at all?

Packet General’s Data Security and PCI Compliance solutions run on a dedicated appliance, based on a “Just Enough Operating System” (JeOS) to minimize exposure.

This appliance actually improves not just the security of your data, but ensures your Operating System is secure and up to date. With only 4 services and a footprint < 600MB this is an ideal solution for running even a normal MySQL installation. Security upgrades can also be provided as an automated feature, eliminating the need for this management internally.

Tomorrow in the MySQL Webinar How to secure MySQL data and achieve PCI compliance which is being held Thursday, September 11, …