Replication in MySQL is the dynamic process of synchronizing data between a primary (master) database server and one or more secondary (slave) database servers in near-real time. Using this process, it’s possible to create copies of one or more databases so that even if the primary server fails, data can still be recovered from one of the secondary servers.

Replication is essential for many applications, and the lack of replication support was a major drawback to MySQL compared to other relational database management systems (RDBMSs). MySQL 3.23 was the first version to introduce replication support, and support has improved continually in subsequent versions. However, MySQL is still best suited for one-way replication, where you have one master and one or more slaves.

TIP

As much as possible, try to use the same version of MySQL for both the master and slave server(s). A version …

Equally important as backing up data in a MySQL database is the ability to restor data.

Most books on the subject emphasize the importance of backing up your data regularly (and rightly so), but restoring the data is an often-overlooked aspect of this process. Backed-up files are useless if they can’t be accessed. Accordingly, you should regularly restore your files from backup to make certain they can be used in an emergency. In fact, it might not be too much to say that a backup job isn’t complete until you’ve confirmed that the backup files can be restored. Besides the peace of mind you’ll achieve, it pays to be thoroughly familiar with the process, because you certainly don’t want to waste time learning the restore procedure after the system goes down.

In the preceding section, you learned that the output of …

You might need to restore corrupted tables (or even an entire database) from your backups and use the update logs if a table gets damaged or deleted by accident. In case of relatively minor damage, however, MySQL provides several options for table repair. This next section deals with what you can do if this is the case.

Checking Tables for Errors

The first thing to do if you suspect something is wrong is to check the table for errors. The myisamchk utility is one way to check a table. To invoke this utility, execute the command myisamchk table-file.

Because myisamchk requires exclusive access to the tables, a good idea is to take the server offline before running it. This way, you needn’t worry about coordinating access between clients. In addition, you can run several options when you check a table for errors, as shown in Table 1.

The following example runs myisamchk with the …

Hi all MySQL afficionados !

I just wanted to keep you informed that Fosdem’s organization opened the proposals for Devrooms.

As every year now, we submitted our participation. As soon as our devroom will be approved, the Call For Papers will be published.

Stay tuned for more information.

Cheers !

ARIN is the American Registry for Internet Numbers, the organisation that hands out the blocks IP addresses.

Each region has its own, for instance Australia/Pacific has APNIC. Naturally, they work very closely together.

Open Query can assist you with planning and deployment of IPv6 capabilities on your front-end servers, as well as at the back-end if you wish. Not all hosting providers support IPv6, but many good ones do. MySQL/MariaDB can operate in a native IPv6 or dual stack environment. Open Query enabled its own front-end servers for IPv6 a number of years ago already.

http://teamarin.net/2015/09/24/arin-reaches-ipv4-depletion/

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The post Hello world! appeared first on ScaleDB Extending MySQL for Volume and Velocity.

In two earlier posts, I gave some examples on how to use Perl to send tweets stored in a MySQL database to Twitter, and then how to automatically reply to your retweets with a “thanks”. In this post, I will show you how to automatically download your direct messages from Twitter, store the messages in a MySQL database, and then delete them.

I don’t like the way Twitter makes me read my direct messages. Granted, the majority of them are not real messages. The message is usually thanking me for following the sender, and then there is a personal website link or a link to a product they are selling. But if I want to delete a direct message, I have to …

Recently we encountered an issue with aurora, where our cpu started spiking every X minutes. (X < 30)

we had like 20-30 connections, out of which majority were inserts and a few selects.

every time the spike occurred our inserts would start waiting and waiting….

here is innotop output

we checked our code. nothing major had changed.

The mysql error log had this mysterious message which i could not trace in the mysql/percona/maria source.

“Innodb: Retracted crabbing in btr_cur_search_to_nth_level 33001 times since restart”

if you get to know the meaning of this – please do let me know – would love to understand this.

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Hi all, keeping our steady release cycle, it is time again to do another preview release of MySQL Group Replication, the plugin that brings multi-master update everywhere to MySQL, like we described in Hello World post.

We are very proud to do the fourth preview release of MySQL Group Replication, version 0.5.0 based on MySQL Server 5.7.8, which introduces new exciting features, please enjoy the highlights!…

One of the key features of MySQL Group Replication is its distributed recovery mechanism. Whenever a new member joins a server group, making use of this plugin component, it reaches to a suitable donor and fetches the data that it misses up until the point it is declared online.…