There are two ways InnoDB can organize tablespaces. First is when all data, indexes and system buffers are stored in a single tablespace. This is typicaly one or several ibdata files. A well known innodb_file_per_table option brings the second one. Tables and system areas are split into different files. Usually system tablespace is located in ibdata1 file and every InnoDB table has two files e.g.  actor.frm and actor.ibd.

The annoying thing about .ibd files you can’t easily copy the an .ibd file to another MySQL server. If you try to very often you’ll get an error in the log:

InnoDB: Error: tablespace id is 10 in the data dictionary
InnoDB: but in file ./sakila/actor.ibd it is 15!

However sometimes you have to connect the .ibd file to an alien ibdata1.

There are several situation when you have to:

1. ibdata1 is erroneously removed

2. ibdata1 is …

A user on a linux user group mailing list asked about this, and I was one of the people replying. Re-posting here as I reckon it’s of wider interest.

> [...] tens of gigs of data in MySQL databases. > Some in memory tables, some MyISAM, a fair bit InnoDB. According to my > understanding, when one doesn’t have several hours to take a DB > offline and do dbbackup, there was/is ibbackup from InnoBase.. but now > that MySQL and InnoBase have both been ‘Oracle Enterprised’, said > product is now restricted to MySQL Enterprise customers.. > > Some quick searching has suggested Percona XtraBackup as a potential > FOSS alternative. > What backup techniques do people employ around these parts for backups > of large mixed MySQL data sets where downtime *must* be minimised? > > Has your backup plan ever been put to the test?

You should put it to the test regularly, not just when it’s needed. …

On September 8, 2010 Oracle announced the availability of Oracle Solaris Cluster 3.3

Oracle Solaris Cluster 3.3, built on the solid foundation of Oracle Solaris, offers the 
most extensive Oracle enterprise High Availability and Disaster Recovery solutions for the 
largest portfolio of mission-critical applications.

Integrated and thoroughly tested with Oracle's Sun servers, storage, connectivity 
solutions and Solaris 10 features, Oracle Solaris Cluster is now qualified with Solaris 
Trusted Extensions, supports Infiniband for general networking or storage usage, and can 
be deployed with Oracle Unified Storage in Campus Cluster configurations. It extends its 
applications support to new Oracle applications such as Oracle Business Intelligence, 
PeopleSoft, TimesTen, and MySQL Cluster.

The single, integrated HA and DR solution enables multi-tier deployments in virtualized 
environments. In this release, Oracle Solaris Containers clusters supports even more 
configurations …

On September 8, 2010 Oracle announced the availability of Oracle Solaris Cluster 3.3

Oracle Solaris Cluster 3.3, built on the solid foundation of Oracle Solaris, offers the 
most extensive Oracle enterprise High Availability and Disaster Recovery solutions for the 
largest portfolio of mission-critical applications.

Integrated and thoroughly tested with Oracle's Sun servers, storage, connectivity 
solutions and Solaris 10 features, Oracle Solaris Cluster is now qualified with Solaris 
Trusted Extensions, supports Infiniband for general networking or storage usage, and can 
be deployed with Oracle Unified Storage in Campus Cluster configurations. It extends its 
applications support to new Oracle applications such as Oracle Business Intelligence, 
PeopleSoft, TimesTen, and MySQL Cluster.

The single, integrated HA and DR solution enables multi-tier deployments in virtualized 
environments. In this release, Oracle Solaris Containers clusters supports even more 
configurations …

On September 8, 2010 Oracle announced the availability of Oracle Solaris Cluster 3.3

Oracle Solaris Cluster 3.3, built on the solid foundation of Oracle Solaris, offers the 
most extensive Oracle enterprise High Availability and Disaster Recovery solutions for the 
largest portfolio of mission-critical applications.

Integrated and thoroughly tested with Oracle's Sun servers, storage, connectivity 
solutions and Solaris 10 features, Oracle Solaris Cluster is now qualified with Solaris 
Trusted Extensions, supports Infiniband for general networking or storage usage, and can 
be deployed with Oracle Unified Storage in Campus Cluster configurations. It extends its 
applications support to new Oracle applications such as Oracle Business Intelligence, 
PeopleSoft, TimesTen, and MySQL Cluster.

The single, integrated HA and DR solution enables multi-tier deployments in virtualized 
environments. In this release, Oracle Solaris Containers clusters supports even more 
configurations …

In my previous posts I highlighted that one of improvements in Percona Server is support of innodb_log_file_size > 4G. This test was done using Percona Server 5.5.7, but the same performance expected for InnoDB-plugin and MySQL 5.5.

The valid question how long is recovery in this case, so let's test it. I took the same tpcc-mysql 1000W workload with 52GB and 144GB innodb_buffer_pool_size with data located on Virident tachIOn card and killed mysqld after 30 mins of work.

The recovery time after start is:
for 52GB innodb_buffer_pool_size:

PLAIN TEXT CODE:

1. 101220 …

Although MyISAM has been the default storage engine for MySQL but its soon going to change with the release of MySQL server 5.5. Not only that, more and more people are shifting over to the Innodb storage engine and the reasons for that is the tremendous benefits, not only in terms of performance, concurrency, ACID-transactions, foreign key constraints, but also because of the way it helps out the DBA with hot-backups support, automatic crash recovery and avoiding data inconsistencies which can prove to be a pain with MyISAM. In this article I try to hammer out the reasons why you should move on to using Innodb instead of MyISAM.

Before I start a story about the data recovery case I worked on yesterday, here's a quick tip - having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously - in most of the recovery cases I worked on, customers did have some sort of backup, but it just wasn't working, complete and what not. Someone set it up and never bothered to check if it still works after a while.

Anyway, this post is not really about the backups but rather about few interesting things I learned during last recovery case.

First, some facts about the system and how data was lost:

• MySQL had a dedicated partition on XFS file system
• Server was running innodb_file_per_table
• There was a …

I have a 5G mysqldump which takes 30 minutes to restore from backup.  That means that when the database reaches 50G, it should take 30x10=5 hours to restore.  Right?  Wrong.

Mysqldump recovery time is not linear.  Bigger tables, or tables with more indexes will always take more time to restore.

If I restore from a raw backup (LVM snapshot, xtrabackup, innodb hot backup), it is very easy to model how much longer recovery time will take:

Backup is 80G
Copy is at 70MB/s.
10G is already complete.
= ((80-10) * 1024)/70/60 = ~17 minutes


I can tell progress with mysqldump by monitoring the rate at which show global status like 'Handler_write'; increases and compare it to my knowledge of about how many rows are in each table.  But progress != a magic number like "17 minutes".  Not unless I do a lot of complex modeling.

I am …

MySQL is the most popular open-source database in the world. It has the distinction of being the only database that is used in every continent. Yes, even Antartica!!! The reasons for such popularity is its availability, performance, robustness, etc. It provides three types of database engines, MyISAM, InnoDB, and MySQL Archive. Out of these, the MyISAM table is the default table type. It is fast, simple, and allows full-text searching. Although it is reliable, it can become corrupt and, thus, inaccessible following a system crash. You should use appropriate corrective measures to repair MySQL database. However, if you are not able to do so then you should use a third-party MySQL recovery software to do so.

Consider a scenario wherein you have MySQL 5.0.22 database running in your system. You use it for MediaWiki installation that is reported as corrupt. When you try to repair the table, the following error message is displayed:
…