The unDROP for InnoDB tool can be used to recover corrupt MySQL database. In this post we will show how to repair MySQL database if its files became corrupted and even innodb_force_recovery=6 doesn’t help.

The corruption of InnoDB tablespace may be caused by many reasons. A dying hard drive can write garbage, thus page checksum will be wrong. InnoDB then reports to the error log:

InnoDB: Database page corruption on disk or a failed
InnoDB: file read of page 4.

MySQL is well know for poor start-up script. A simple upgrade procedure may end up with two mysqld processes writing to the same tablespace. That leads to the corruption too. Sometimes power reset corrupts not only InnoDB files, but file system becomes unusable for the operating system.

InnoDB …

Ok, so I wanted to look into the new compression options of MEB 3.10.

And I would like to share my tests with you. Remember, they’re just this, tests, so please feel free to copy n paste and obtain your own results and conclusions, and should I say it, baselines, in order to compare future behaviour, on your own system.

An Oracle Linux 6.3 virtual machine with 3Gb RAM, 2 virtual threads, on a 1x quad core, windows laptop. Not pretty, but hey.

So, these tests are solely about backup. I’ll do restore when I get some *more* time.

First up, lets compare like with like, i.e. MEB version 3.9 & 3.10:

Let’s make this interesting, hence, want to use as much resources available as possible, read, write, process threads and number of buffers.

mysqlbackup --user=root --password=oracle --socket=/tmp/mysql5614.sock \
--backup-dir=/home/mysql/MEB/test --with-timestamp …

Ok, so I wanted to look into the new compression options of MEB 3.10.

And I would like to share my tests with you. Remember, they’re just this, tests, so please feel free to copy n paste and obtain your own results and conclusions, and should I say it, baselines, in order to compare future behaviour, on your own system.

An Oracle Linux 6.3 virtual machine with 3Gb RAM, 2 virtual threads, on a 1x quad core, windows laptop. Not pretty, but hey.

So, these tests are solely about backup. I’ll do restore when I get some *more* time.

First up, lets compare like with like, i.e. MEB version 3.9 & 3.10:

Let’s make this interesting, hence, want to use as much resources available as possible, read, write, process threads and number of buffers.

mysqlbackup --user=root --password=oracle --socket=/tmp/mysql5614.sock \
--backup-dir=/home/mysql/MEB/test --with-timestamp …

In addition to my recent post, I just had to go into using the –use-tts for specific tables and selective backup sets.

As all my schemas were employeesn, I thought it would be a good idea to run:

mysqlbackup -uroot --socket=/tmp/mysql.sock --backup-dir=/home/mysql/MEB/restore \
--with-timestamp --use-tts --include=employees* backup

as I want all the tables. If I only wanted a specific table, say ‘salaries’ I could have done:

mysqlbackup -uroot --socket=/tmp/mysql.sock --backup-dir=/home/mysql/MEB/restore \
--with-timestamp --use-tts --include=employees*\.*salaries backup

and backup just the ‘salaries’ tables but from all the employeesn databases.

then.. be a mean little dba:

drop database employees;
drop database employees10;
drop database employees11;
..
..
drop database employees2;
drop database employees20;
drop database …

In this post I go into some performance metrics and time spent on using MySQL Enterprise Backup instead of mysqldump, and seeing how far I could go with some parallel configuration.

Setup:

It’s on an old laptop:

–Ubuntu 12.04 LTS, 32bit Intel Pentium M 1.86Ghz, 2Gb –Source disk:  internal 80Gb ATA ST9808211A –Destination:  external 1Tb SAMSUNG HD103SI –MySQL Enterprise Edition 5.6.15 –MySQL Enterprise Backup 3.9.0 –Employees sample database duplicated via MySQL Utilities 1.3.6 (on Win7 PC) to generate a ~5Gb MySQL Server. And to simulate data size, I used the MySQL Utilities:

mysqldbcopy --source=root:pass@host:3356 --destination=root:pass@host:3356 employees:employees1 \
employees:employees2 employees:employees3 employees:employees4 ... employees:employees18 \
employees:employees19 employees:employees20

…

In this post I go into some performance metrics and time spent on using MySQL Enterprise Backup instead of mysqldump, and seeing how far I could go with some parallel configuration.

Setup:

It’s on an old laptop:

–Ubuntu 12.04 LTS, 32bit Intel Pentium M 1.86Ghz, 2Gb –Source disk:  internal 80Gb ATA ST9808211A –Destination:  external 1Tb SAMSUNG HD103SI –MySQL Enterprise Edition 5.6.15 –MySQL Enterprise Backup 3.9.0 –Employees sample database duplicated via MySQL Utilities 1.3.6 (on Win7 PC) to generate a ~5Gb MySQL Server. And to simulate data size, I used the MySQL Utilities:

mysqldbcopy --source=root:pass@host:3356 --destination=root:pass@host:3356 employees:employees1 \
employees:employees2 employees:employees3 employees:employees4 ... employees:employees18 \
employees:employees19 employees:employees20

…

December 19, 2013 By Severalnines

Database clusters are pretty sophisticated distributed systems with complex dependencies between nodes. The failure of a node will generally impact the overall cluster, as the remaining nodes need to reconfigure themselves to continue to operate without the failed node. Since re-introducing a node will also affect the existing cluster, the timing could therefore be dependent on the state of the other nodes in the cluster. Repair and restarts often needs to be performed in a particular order in compliance with the redundancy model of the cluster so as not to jeopardize the normal functioning of existing nodes.

Webinar: Repair and Recovery for your MySQL, MariaDB and MongoDB/TokuMX clusters

…

October 28, 2013 By Severalnines

Data protection is vital for DB admins, especially when it involves data that is accessed and updated 24 hours a day. Clustering and replication are techniques that provide protection against failures, but what if a user or DBA issues a detrimental command against one of the databases? A user might erroneously delete or update the contents of one or more tables, drop database objects that are still needed during an update to an application, or run a large batch update that fails midway. How do we recover lost data? 

In a previous post, we showed you how to do a full restore from backup. Great, now you’ve restored up to the last incremental backup that was done at 6am this morning. But how about the rest of the data?

This is where you’d do a …

Here’s a look at using MySQL Enterprise Backup in a specific example:

Consider a Backup Policy – Full Backup of the environment. – Complemental Incremental backups & online BinLogs. And the Restore: – Logical Restore. – Online, Zero impact. – Partial, single database, group of tables. The Backup A working environment, with 4 databases, of which 2 will require restoration. Full backup with MySQL Enterprise Backup:

mysqlbackup --user=root --socket=/tmp/mysql.sock \
  --backup-dir=/home/mysql/voju5/backup/ \
  --with-timestamp backup

Test preparation Create 4 different databases, where the structure & content is the same.

create database v5_1; use v5_1; create table `voju5` (
  `ID` int(7) NOT NULL AUTO_INCREMENT,
  `Name` char(20) NOT NULL DEFAULT '‘,
   PRIMARY KEY (`ID`) ) ENGINE=InnoDB;
create database v5_2; use v5_2; create table `voju5` (..);
create database v5_3; use v5_3; create …

Here’s a look at using MySQL Enterprise Backup in a specific example:

Consider a Backup Policy – Full Backup of the environment. – Complemental Incremental backups & online BinLogs. And the Restore: – Logical Restore. – Online, Zero impact. – Partial, single database, group of tables. The Backup A working environment, with 4 databases, of which 2 will require restoration. Full backup with MySQL Enterprise Backup:

mysqlbackup --user=root --socket=/tmp/mysql.sock \
  --backup-dir=/home/mysql/voju5/backup/ \
  --with-timestamp backup

Test preparation Create 4 different databases, where the structure & content is the same.

create database v5_1; use v5_1; create table `voju5` (
  `ID` int(7) NOT NULL AUTO_INCREMENT,
  `Name` char(20) NOT NULL DEFAULT '‘,
   PRIMARY KEY (`ID`) ) ENGINE=InnoDB;
create database v5_2; use v5_2; create table `voju5` (..);
create database v5_3; use v5_3; create …