April 16, 2014

Innodb Recovery Update – The tricks what failed.

As I wrote we had been recovering corrupted Innodb Tablespace and it is finally done now. As this was over than 1TB worth of data we really tried to avoid dumping the data and find some other way to recovery. Examining Innodb page content and crash information we figured out it should be page of […]

How to estimate time it takes Innodb to Recover ?

Today seems to be Innodb day in our Blog, but well this is the question which pops ups quite frequently in Innodb talks and during consulting engagements. It is well known to get better performance you should normally set innodb_log_file_size large. We however usually recommend caution as it may significantly increase recovery time if Innodb […]

Undo area size restriction needed for Innodb

As you can read from my Innodb Architecture and Performance Optimization presentation Innodb automatically manages undo area in system tablespace so you never need to care about it. I present it as positive feature reducing administration effort needed but it also can cause a troubles as it happened for me today: InnoDB: 11 transaction(s) which […]

Long PRIMARY KEY for Innodb tables

I’ve written and spoke a lot about using short PRIMARY KEYs with Innodb tables due to the fact all other key will refer to the rows by primary key. I also recommended to use sequential primary keys so you do not end up having random primary key BTREE updates which can be very expensive. Today […]

Using LVM for MySQL Backup and Replication Setup

If someone asks me about MySQL Backup advice my first question would be if they have LVM installed or have some systems with similar features set for other operation systems. Veritas File System can do it for Solaris. Most SAN systems would work as well. What is really needed is ability to create atomic snapshot […]

MySQL Crash Recovery

MySQL is known for its stability but as any other application it has bugs so it may crash sometime. Also operation system may be flawed, hardware has problems or simply power can go down which all mean similar things – MySQL Shutdown is unexpected and there could be various inconsistences. And this is not only […]

Choosing proper innodb_log_file_size

If you’re doing significant amount of writes to Innodb tables decent size of innodb_log_file_size is important for MySQL Performance. However setting it too large will increase recovery time, so in case of MySQL crash or power failure it may take long time before MySQL Server is operational again. So how to find the optimal combination […]

Introducing backup locks in Percona Server

TL;DR version: The backup locks feature introduced in Percona Server 5.6.16-64.0 is a lightweight alternative to FLUSH TABLES WITH READ LOCK and can be used to take both physical and logical backups with less downtime on busy servers. To employ the feature with mysqldump, use mysqldump –lock-for-backup –single-transaction. The next release of Percona XtraBackup will […]

Inexpensive SSDs for Database Workloads

The cost of SSDs has been dropping rapidly, and at the time of this writing, 2.5-drives have reached the 1TB capacity mark.  You can actually get inexpensive drives for as little as 60 cents per GB. Even inexpensive SSDs can perform tens of thousands of IOPs and come with 1.5M – 2M hous MTBF and […]

Limited disk space? Compact backups with Percona Xtrabackup 2.1

One very interesting feature, “Compact Backup,” is introduced in Percona XtraBackup 2.1. You can run “compact backups” with the  –compact option, which is very useful for those who have limited disk space to keep the database backup. Now let’s first understand how it works. When we are using –compact option with Innobackupex, it will omit the secondary […]