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Displaying posts with tag: mysql recovery (reset)
A tale of Corrupt InnoDB table, MySQL crash & recovery

I’m going to narrate you a story that happened around a crashing MyQL, Corrupted InnoDB table and finally the recovery by table restore. We will see how our database administrator detected the issue and what he did to resolve it. A day in MySQL Database Consultant’s day was taking its shape while a friend called […]

The Q&A: Creating best-in-class backup solutions for your MySQL environment

Thank you for attending my July 15 webinar, “Creating Best in Class Backup solutions for your MySQL environment.” Due to the amount of content we discussed and some minor technical difficulties faced near the end of webinar we have decided to cover the final two slides of the presentation along with the questions asked by attendees during the webinar via this blog post.

The slides are available for download. And you can watch the webinar in it’s entirety here.

The final two slides were about our tips for having a …

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Bypassing SST in Percona XtraDB Cluster with binary logs

In my previous post, I used incremental backups in Percona XtraBackup as a method for rebuilding a Percona XtraDB Cluster (PXC) node without triggering an actual SST. Practically this reproduces the SST steps, but it can be handy if you already had backups available to use.

In this post, I want to present another methodology for this that also uses a full backup, but instead of incrementals uses any binary logs that the cluster may be producing.

Binary logs on PXC

Binary logs are not strictly needed in PXC for replication, but …

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Bypassing SST in Percona XtraDB Cluster with incremental backups

Beware the SST

In Percona XtraDB Cluster (PXC) I often run across users who are fearful of SSTs on their clusters. I’ve always maintained that if you can’t cope with a SST, PXC may not be right for you, but that doesn’t change the fact that SSTs with multiple Terabytes of data can be quite costly.

SST, by current definition, is a full backup of a Donor to Joiner.  The most popular method is Percona XtraBackup, so we’re talking about a donor node that must:

  1. Run a full XtraBackup that reads its entire datadir
  2. Keep up with Galera replication to it as much as possible (though laggy donors don’t send flow control)
  3. Possibly still be serving application traffic if you don’t remove Donors from rotation.
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Restore / Recover dropped MySQL database from binary logs

In this post I will share a recovery scenario of a MySQL database restore from the binary logs. Recently someone accidentally dropped an important MySQL database and the backup was not present! As we know the the binary log contains DMLs to table data and that’s where our hope lies. Luckily the binary log retention […]

With InnoDB’s Transportable Tablespaces, Recovering Data from Stranded .ibd Files is a Thing of the Past

Being a data recovery specialist and having recovered countless GBs of corrupted, and/or stranded, InnoDB data in my days, I am very happy to hear about the new InnoDB Transportable Tablespaces coming in MySQL 5.6!

Back in the day, if you had a stranded .ibd file (the individual InnoDB data file with –innodb-file-per-table option), you basically had nothing (even though that file contained all of the data). This was because unless you had the original instance that that particular .ibd file (table) originated from, there was no way to load it, import, or dump from it. So it was not of much use, though all the data was *right* there.

Thus I created the method of Recovering an InnoDB table from only an .ibd file (I should note that this was before the …

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Incorrect Information in .FRM File of InnoDB Table

MySQL organizes all the data as tables, irrespective of storage engine used. If you are using MySQL with InnoDB tables, these tables might get corrupt due to hardware faults, unexpected power failure, MySQL code errors, kernel bugs and other similar reasons. In such cases, InnoDB will typically give some errors indicating table corruption. As a data restoration source, you will need to use your latest database backup. But in case if backup fails to restore required information or doesn’t exist, you should scan your damaged database using third-party MySQL Repair or MySQL Recovery tools.

You might encounter the similar error message while accessing an InnoDB table:

“#1033 - Incorrect information in file: '"table name" .frm”

MySQL crashes after you receive this error message.

Cause: You receive this error message if …

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A small analysis on MySQL database corruption and the possible resolution

MySQL is a reliable and higher secure relational database management system that was developed to deal with much bigger databases. Its improved performance, high speed and connectivity make it a better client-server application that has a support for different back-ends, client programs, and Application Programming Interfaces (APIs). But one often faces corruption issues while working with MySQL databases. The corruption may occur due to any reason, such as quitting application in the middle of a write operation, improper system shutdown, hardware issues etc. All these reasons may prevent you from accessing your important databases tables and other objects in the corrupt MySQL database. To recover back all your inaccessible and valuable data in such situations, you need to go for MySQL recovery through a reliable third party utility.

For instance, you may get an error message reading:

"Table …

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The Safe Way to Recover MySQL Database

MySQL is a relational database application, which is widely used for many web based projects. Like any other database application, MySQL also stores various important data. Hence, any problem with the database, results in the complete inaccessibility of the valuable data, which may lead to huge business loss. However, there are many MySQL recovery software that can help you deal with the MySQL problems and recover your precious data back.

MySQL runs as a database server and provides multi-user access to many different databases. For its usability and features, this application is used by many big World Wide Web products, such as Google, Wikipedia, Facebook etc. However, there are occasions, when MySQL gets corrupted and all the data in it becomes completely inaccessible.

There are thousands of such reasons behind possible MySQL corruption. Below listed, are some of the most prominent ones:

1. …

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MySQL recovery utility for any instance of corruption

In order to start your MySQL server, you used to type the whole path like: "C:\mysql\bin\mysql123" in your DOS prompt. However, sometimes, the MySQL server fails to start with this usual command and the reason may be any possible case of database corruption or damage. In such a case, you cannot be able to access your database and need any MySQL repair utility to repair the troubled MySQL database and recover the data thereof.
In case of any corruption, you may encounter an error message at the start of the MySQL server, which may be as below:

"Default storage engine is not available"

Moreover, in order to resolve the error, if you reinstall the MySQL server without removing the data directory, the server starts normally. However, to your utter dismay, while accessing the any database table, you may encounter another error message on the screen as below:

"ERROR 1146 (42S02): Table 'Tablename' doesn't …

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