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Showing entries 1 to 10 of 34725 10 Older Entries
MySQL replication monitoring 101
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Replication is the process that transfers data from an active master to a slave server, which reproduces the data stream to achieve, as best as possible, a faithful copy of the data in the master.

To check replication health, you may start with sampling the service, i.e. committing some Sentinel value in the master and retrieving it from the slave.

Sentinel data: Tap tap… Is this thing on?

If you want to make sure that replication is working, the easiest test is using replication itself to see …

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Unknown column ‘smth’ in ‘field list’ -> Oldie but goodie error
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There is an error which is definitely new to people which have encountered such situation at first time.
It was reported a long time before:
#1689 -> 28 Oct 2003 4:46
#1478 -> 4 Oct 2003 10:58
#7501 -> 23 Dec 2004 5:35

Error is -> ERROR 1054 (42S22): Unknown column ‘c2′ in ‘field list’
The Place where you can encounter …

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Why base64-output=DECODE-ROWS does not print row events in MySQL binary logs
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Lately I saw many cases when users specified option


  to print out a statement representation of row events in MySQL binary logs just to get nothing. Reason for this is obvious: option


  does not convert row events into its string representation, this is job of option


. But why users mix these two options so often? This blog post is result of my investigations.

There are already two great blog posts about printing row events on the …

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Webinar Replay & Slides: Become a MySQL DBA - Designing High Availability for MySQL
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Thanks to everyone who joined us yesterday for this live session on designing HA for MySQL led by Krzysztof Książek, Senior Support Engineer at Severalnines. The replay and slides to the webinar are now available to watch and read online via the links below.

Watch the replay:

Become a MySQL DBA - webinar series: Which High Availability solution? from Severalnines …

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Ansible and Loading MySQL Databases Part II
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Loading databases on virtual systems is not as straight forward as it should be. Last time the foundation for using Ansible was set down on our quest to be able to have fully functional database servers on virtual servers automatically. But that prompted a few of you to remind me that you do not always need Ansible.

Without Ansible
You can have Vagrant do the work. Modify the vagrant file to run a script to run a script when …

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New! MySQL Connector/Arduino release-1.0.4 GA and Documentation
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After several iterations and a long period of community evaluation, I am happy to report I've released the newest, stable release of the MySQL Connector/Arduino. This library is designed to allow you to connect your Arduino via an Ethernet or WiFi shield to a MySQL database server running on your network (or the Internet!).

New Documentation!Best of all, I've written a reference manual that includes examples of how to use the connector in a variety of ways. Included in the document are advice on how to write your sketches, troubleshooting tips, and a long FAQ compiled from the many questions from my blogs.

Changes …

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MySQL in a USB, with a little help of Fabric
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If you’ve wanted to see how well MySQL Fabric actually works and how easy it makes setting up replication and switching Masters & Slaves back and forth, with a sample use case of having the master stored in a USB stick, then feel free to have a look at:

o la versión en Español:

Please let …

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New Optimizer Hints in MySQL
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The MySQL optimizer has a well known special system variable—optimizer_switch—which allows control of various optimizer modes such as index condition pushdown (ICP), batched key access, etc. One big disadvantage of using the optimizer_switch, however, is that changing its value is an extra step in the query execution. Another disadvantage of the …

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Can’t Be Any Faster Than That: A Real-Life Experiment with Latency in a Geo-distributed Environment
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A question frequently asked is how much latency does Galera have in geo-distributed environments. After all, snail mail can also be used for database replication, but the latency will not be acceptable.

Let’s see how Galera performs.

A Two-Datacenter Setup

We start by creating a two-node cluster using a pair of Amazon EC2 regions that are as far apart Internet-wise as it gets – Sydney and São Paulo. The underwater cable maps do not show a direct link between Australia and South …

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Pseudo GTID is a technique where we inject Globally Unique entries into MySQL, gaining GTID abilities without using GTID. It is supported by orchestrator and described in more detail here, here and here.

Quick recap: we can join two slaves to replicate from one …

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Showing entries 1 to 10 of 34725 10 Older Entries

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