The latest from the MySQL community

Every ones loves hands-on tutorials with code snippets and stuff to establish the knowledge that something can be done. So here is my first one; MySQL Enterprise Backup 3.5. The new and shiny backup solution for MySQL. Our clients, for a long time, are asking for an enterprise ready, stable, safe, quick, easy, feature rich, [...]

Previous podcasts in the backup series:
Backup Series #1: Glossary
Backup Series #2: Backup Tools You Already Have (mysqlhotcopy and mysqldump)

Show Notes:

This week we have Lenz Grimmer with us to speak about snapshot backups in general, MySQL backups with snapshots, and mylvmbackup, a script Lenz wrote and maintains to easily take consistent MySQL snapshot backups.

Rate/review us in iTunes (website with a link to open in iTunes, or link to iTunes [may not work in Chrome, does work in Firefox]).

…

On Thursday, February 10, at 10am PST, there is a free webinar about Managing Big Data with Percona Server, XtraBackup and Tungsten. Quoting from the announcement:

Big data is a big problem for growing SaaS businesses and large web applications. In this webinar, we'll teach you how to set up Percona Server, XtraBackup, and Tungsten to manage Terabyte+ databases and scale to millions of transactions a day. We'll discuss the latest features for high transaction performance like InnoDB buffer pool dump/restore and HandlerSocket, our favorite tricks for backup, restore, and provisioning of large data sets, and how to replicate scalably and safely using Tungsten Replicator with parallel apply.

The presenters are representatives of both Percona and …

Show notes:

Previous backup series podcast:
Backup glossary [Backup series #1]

Feedback:
In the backup glossary we asked if anyone knew how to get logical data out of physical InnoDB files. Mike Hamrick of Blue Gecko wrote in to say that Percona's InnoDB recovery tool helps to do just that. He writes:

"The 'page_parser' tool will read ibdata files or individual .ibd files and turn them into a series of 16k page files suitable for processing with a tool called 'constraints_parser' which spits out a number of tab separated lines of table data suitable for a LOAD DATA INFILE.

read more

Show Notes:
[note: about 11 minutes in, Sarah's audio gets a little noisier, and our audio engineer simply could not get rid of all the noise]

A slave is not a backup, although a slave can be used to get backups more easily.
You don't test backups, you test restores.
logical vs. physical
cold vs. hot vs. warm
consistent vs. inconsistent

strings(1) - Linux man page
"A foolish consistency is the hobgoblin of little minds" - Ralph Waldo Emerson [note: Sheeri misquotes this as "Consistency is the hobgoblin of little minds"]

read more

MySQL is a popular database management system, a most widely used for web databases, offers efficient techniques to ensure absolute integrity of the database. When you start MySQLD (MySQL Server), it automatically examines all the database tables for integrity. MySQL Server also fixes the tables if they are marked as ´not closed properly´ or ´crashed´. It backs up all the corrupted database tables and makes their entries in the error log. Though, it works in a number of cases, but cannot necessarily fix all the corruption issues and fails to recover MySQL database.

The MySQLD technique cannot repair MySQL database if it is severely damaged. As a practical scenario, where MySQL Server cannot handle the table corruption, you may encounter the below error message-

"Got an error from thread_id=1, mi_dynrec.c:368"

The above error message occurs when you start the MySQL server for accessing the database …

Bugzilla is a web-based bug tracking and testing application that is used by many software development companies. It extensively various databases including MySQL for its backend support especially because both of these applications are freely available. Although this tool runs pretty fine in most cases, it can get stalled when the some of the MySQL tables get corrupt. In such cases, you are unable to perform various tasks on the database. You can use the 'myisamchk' command with different parameters to repair MySQL database. If it does not work, then you should use a professional MySQL recovery software to recover MySQL database.

Discussing a similar situation in Bugzilla, consider you get the following error message while generating a bugs report:

"undef error - DBD::mysql::db selectrow_array failed: Table 'attach_data' is
marked as crashed …

A question that came up during the MySQL track at the UKOUG conference in Birmingham was "Can I exclude only a few databases from mysqldump? Let's say that I have 50 databases, and I want to dump all of them, except a few."
As many know, mysqldump has an option to ignore specific tables. SO if you have 1,000 tables in a databases, you can tell mysqldump to dump all the tables except a few ones.
There is no corresponding option to exclude one or more databases.
However, if you know your command line tools, the solution is easy:
First, we get the list of all databases:

mysql -B -N -e 'show databases'
information_schema
employees
five
four
mysql
one
performance_schema
six
test
three
two

-B forces batch mode (no dashes box around the data), while -N gets the result without the headers.
Now, let's say that we want to exclude databases four, …

The open-source xtrabackup tool from Percona brings much needed hot backup functionality to MySQL deployments.  In this database journal article we discuss logical, cold, and hot backups, then explain how to use xtrabackup on your MyISAM, InnoDB, and XtraDB tables to create at-the-ready backups.  We then take you through the step-by-step process to restore them, and even the process of point-in-time recovery too.

Database Journal – Hotbackups with Percona’s Xtrabackup

In my continuing MySQL 5.5 blog series, today I am covering what's new on the replication front.  MySQL replication is my favorite server feature and what drew me to MySQL during my tenure with Embarcadero Technologies.  Others seem to agree as based on community and customer surveys, MySQL replication is the most popular and widely used database feature.  Mostly because it is easy to set up and ease, it enables scalability and provides a pretty robust solution for data redundancy, backup and overall availability.  In MySQL 5.5 replication has been enhanced in response to user requests that MySQL replication:

• Ensure data consistency between master and slave servers
• Immediately detect if replication is not working
• Allow a crashed slave to automatically recover from the master relay log
• Allow users to filter …