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Showing entries 1 to 10 of 34589 10 Older Entries
Become a MySQL DBA blog series - Common operations - Replication Topology Changes
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MySQL replication has been available for years, and even though a number of new clustering technologies showed up recently, replication is still very common among MySQL users. It is understandable as replication is a reliable way of moving your data between MySQL instances. Even if you use Galera or NDB cluster, you still may have to rely on MySQL replication to distribute your databases across WAN.

In this blog post we’d like to discuss one of the most common operations DBA has to handle - replication topology changes and planned failover. 

This is the fifth installment in the ‘Become a MySQL …

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MySQL QA Episode 3: How to use the debugging tool GDB
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Welcome to MySQL QA Episode 3: “Debugging: GDB, Backtraces, Frames and Library Dependencies”

In this episode you’ll learn how to use debugging tool GDB. The following debugging topics are covered:


1. GDB Introduction
2. Backtrace, Stack trace
3. Frames
4. Commands & Logging
5. Variables
6. Library dependencies
7. c++filt
8. Handy references
– GDB Cheat sheet (page #2):
– From Crash to testcase: …

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Replication in real-time from Oracle and MySQL into data warehouses and analytics
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Analyzing transactional data is becoming increasingly common, especially as the data sizes and complexity increase and transactional stores are no longer to keep pace with the ever-increasing storage. Although there are many techniques available for loading data, getting effective data in real-time into your data warehouse store is a more difficult problem. VMware Continuent provides capabilities

Linkbench for MySQL & MongoDB with a cached database
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I used linkbench for MySQL and MongoDB to understand OLTP performance on an interesting workload. Here I post results for a cached database and in a few days I will have more results for a database larger than RAM. The summary is that MySQL is a lot faster than MongoDB even when using the same storage engine (RocksDB). I don't know all of the reasons for this and it is possible I made a mistake because this is the first time I have run linkbenchX for MongoDB. …

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TOI wsrep_RSU_method in PXC 5.6.24 and up
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I noticed that in the latest release of Percona XtraDB Cluster (PXC), the behavior of wsrep_RSU_method changed somewhat.  Prior to this release, the variable was GLOBAL only, meaning to use it you would:

mysql> set GLOBAL wsrep_RSU_method='RSU';
mysql> ALTER TABLE ...
mysql> set GLOBAL wsrep_RSU_method='TOI';

This had the (possibly negative) side-effect that ALL DDL’s issued on this node would be affected by the setting while in RSU mode.

So, in this latest release, this …

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Proposal to deprecate INSERT and REPLACE alternative syntax
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In the MySQL team we are currently considering a proposal to deprecate a number of alternative syntax uses with the INSERT and REPLACE commands. To provide examples:

  `Name` char(35) NOT NULL DEFAULT '',
  `CountryCode` char(3) NOT NULL DEFAULT '',
  `District` char(20) NOT NULL DEFAULT '',
  `Population` int(11) NOT NULL DEFAULT '0',
  KEY `CountryCode` (`CountryCode`),
  CONSTRAINT `city_ibfk_1` FOREIGN KEY (`CountryCode`) REFERENCES `Country` (`Code`)

 Name='NewCity', …
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Node Can Not Join the Cluster? How to Debug Issues with SST.
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Galera Cluster has the ability to add new nodes to the cluster by handling internally the transfer of the entire dataset to the new node. The same procedure, called State Snapshot Transfer (SST), applies to nodes that are rejoining the cluster after being down for a longer period of time.

A lot of operations happen during SST and there are various things that could go wrong. This article describes how to configure our server optimally for SST and how to debug any issues that arise.

The Basics

Let’s first consider all the items that play a role in the preparation and configuration of SST.

Selecting …

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Deploy TwinDB agent using Chef on your MySQL fleet
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We are big fans of automation which is also one of the reasons why we started TwinDB. We want to remove the pain around manual redundant jobs and automate them so that you can focus on what is important for your business.

Why Chef?

Awesome Chef

Chef is a great example of how automation can be successfully applied to infrastructure such that your infrastructure becomes easily deployable, manageable, testable and well documented. Whenever, I talk about the benefits of using Chef, I greatly highlight how writing Chef cookbooks …

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Testing MySQL 5.7.7-rc with memory and disc full conditions
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With MySQL 5.7 there will be many improvements and changes.
The most valuable ones are:

1. “General Tablespace” feature -> From now you can place tables to separate tablespaces.
Prior, on our hands there were only “System TableSpace” and “InnoDB file per table” options.

Check for further reading: General Tablespaces
Create statement: Create TableSpace

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Log Buffer #430: A Carnival of the Vanities for DBAs
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This Log Buffer Edition cuts through the crowd and picks some of the outstanding blog posts from Oracle, SQL Server and MySQL.


  • Continuous Delivery (CD) is a software engineering approach in which teams keep producing valuable software in short cycles and ensure that the software can be reliably released at any time.
  • Query existing HBase tables with SQL using Apache Phoenix. …

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Showing entries 1 to 10 of 34589 10 Older Entries

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