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What should I do if MySQL data gets corrupted?
Usually when MySQL data gets corrupted the recommendation is to restore it from the last backup, switch to DR server or take down the affected node if you have Galera cluster to serve data immediately from other nodes.
Why is MY SQL database corrupt in BAK file?
Bugs in SQL server can also cause corruption in the .bak file. Irrespective of the reason behind corruption, inability to restore database from the backup increases risk of losing mission-critical data. How to recover a database from a corrupt .bak file?
Why does MySQL keep spoiling my data files?
There are many ways to spoil data files. Often, corruption is due to defects in the underlying platform, which MySQL relies on to store and retrieve data – disk subsystem, controllers, communication channels, drivers, firmware or other hardware faults.
How to restore MySQL database from physical files?
From the answer of @Vicent, I already restore MySQL database as below: Step 1. Shutdown Mysql server Step 2. Copy database in your database folder (in linux, the default location is /var/lib/mysql). Keep same name of the database, and same name of database in mysql mode. Step 3: Change own and change mode the folder:
Why do I need to restart my NDB Cluster?
There are a number of reasons why a rolling restart might be desirable. These are described in the next few paragraphs. Configuration change. To make a change in the cluster’s configuration, such as adding an SQL node to the cluster, or setting a configuration parameter to a new value. NDB Cluster software upgrade or downgrade.
How to do a rolling restart in ndbd?
The process for performing a rolling restart may be generalized as follows: Stop all cluster management nodes (ndb_mgmd processes), reconfigure them, then restart them. Stop, reconfigure, then restart each cluster data node (ndbd process) in turn. Stop, reconfigure, then restart each cluster SQL node (mysqld process) in turn.
What happens if MySQL node gets a SIGKILL signal?
SIGKILL will not allow the node to do any handling of the signal; the node must exit immediately. For a data node, a SIGKILL signal, for example, increases the probability of a corrupted NDB file system for the node being killed; a corrupted file system requires the data node to be restarted with –initial to completely re-initialize the node.
Why is MySQL relay log not showing up?
The possible reasons are: the master’s binary log is corrupted (you can check this by running ‘mysqlbinlog’ on the binary log), the slave’s relay log is corrupted (you can check this by running ‘mysqlbinlog’ on the relay log), a network problem, or a bug in the master’s or slave’s MySQL code.
How to check the slave’s binary log or relay log?
If you want to check the master’s binary log or slave’s relay log, you will be able to know their names by issuing ‘SHOW SLAVE STATUS’ on this slave. We tried restarting slave’s mysql service and start and stop the slave replication with no help. After further investigation we found that there was an issue with particularly big size of query.
What to do if MySQL server is down?
If the server is down and for any reason mysqlcheck cannot repair your table, you still have an option to perform recovery directly on files using myisamchk. With myisamchk, you need to make sure that the server doesn’t have the tables open.
Is the mysql command line using latin1?
Launch command line MySQL client. The result is that corrupted cyrillic symbols inserted into DB. By default MySQL server is using latin1 character set for each incoming connection. Latin1, as you might know, does not support cyrillic symbols.
What happens when a MyISAM table is corrupted?
MyISAM tables can easily get corrupted when lots of writes happen and a lot of locks happen on that table. The storage engine “writes” data to the filesystem cache, which may take some time before it is flushed to disk. Therefore if your server restarts suddenly, some unknown amount of data in the cache is lost.
Why did I edit.myi file in MySQL?
Telling the server to ignore the .MYI file makes important table metadata stored in the .MYI unavailable to the repair process, which can have deleterious consequences: […..] And finally how to redo this in different ways: Why did you edit the .MYI file? You’re not supposed to do that.