… your backup is consistent. Backing up database which was already corrupted is very nasty problem you want to avoid. Let’s… do to perform backup of MySQL Database (or create slave) using LVM2 on Linux. 1) Connect to MySQL and run FLUSH TABLES WITH… need to point your MySQL Slaves created from this snapshot. 4) Snapshot created, now you want to let MySQL Server to continue, which…
Post: Troubleshooting Relay Log Corruption in MySQL
August 2, 2008 By 5 Comments
… issuing ‘SHOW SLAVE STATUS’ on this slave. This is relay relay log corruption and you can check details in the MySQL Error log file… and potentially recover “corrupted” event to be manually executed on the slaves. Skipping around event makes master and slave potentially inconsistent and you…
Post: MySQL Crash Recovery
July 30, 2006 By 26 Comments
… are synchronized. In MySQL 5.0 XA is taking care of this synchronization. .frm Corruption – Few people know MySQL is not really ACID… vulnerable. master.info corruption – If slave happens to crash you can also have relay logs corruption and master.info being corrupted. Not to mention…
Post: Data Corruption, DRBD and story of bug
November 29, 2010 By 6 Comments
… in the tablespace! InnoDB: The tablespace free space info is corrupt. InnoDB: You may need to dump your InnoDB tables and… that application corrupts data by itself Now to bug 55981. It has MySQL version 5.6, but the problem exists in MySQL 5… if there is possibility that application corrupts data by itself. For this case regular Master-Slave setup (in addition to DRBD) would…
Post: Why you can't rely on a replica for disaster recovery
July 31, 2010 By 25 Comments
…/failover MySQL system, and there was a failover that didn’t work; both the primary and fallback machine had identically corrupted data… InnoDB’s point of view, though, it was still completely corrupted. The “InnoDB file” contained blocks of data that were obviously… way. At a higher level, MySQL replication has the same weakness. If you rely on a MySQL slave for a “backup,” you’ll…
Post: When would you use SAN with MySQL ?
March 9, 2009 By 18 Comments
…of relatively small MySQL installations or managed hosting provider. For large MySQL web MySQL installations using Sharding… problem if you’re running replication Slave as slave thread will issue single IO request …have a glitch causing failure and data corruption (and this is not just a speculation,…
Post: Battery Learning still problem many years after
February 10, 2011 By 7 Comments
…years back. We wrote about it, other people from MySQL Community too. The situation did not get better, … might need to do something such as getting Slave out of rotation when it is going through …write cache without Battery as database should not get corrupted in case of bad crash timing, though you …
Post: Recovery beyond data restore
August 2, 2008 By 11 Comments
… MySQL is R1Soft. Though I have not had a chance to look at it in details. What is about slave loss ? The slave… may have master or relay binary log corruption. Master or Slave running out of space, Slave crashing (and loosing its position on master), Replication breakage (or running out of sync) due to MySQL…
Comment: Finding your MySQL High-Availability solution – The questions
October 17, 2009 By 36 Comments
… into a bad state. * mysql server crash due to a new bug * mysql server crash due to innodb corruption. Over hundreds of servers… and crashed the masters and all slaves via replicaiton (past bugs) though typically the data is corrupted on only one server. You… horror stories with DRBD with the data being corrupted on the master then corrupting the secondary. With Muti-master the main advantage…
Post: Using MyISAM in production
June 17, 2006 By 35 Comments
… rather than wait forever. Hidden corruptions. If could be bad memory OS or MySQL bugs but corruption may happen and go for long unnoticed with MyISAM storage engine. This hidden corruption may later…% correct and always available. For example statistical data. Data on slave servers. If it crashes you can simply re-clone it…
