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Showing entries 1 to 10 of 34766 10 Older Entries
PXC – Incremental State transfers in detail
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IST Basics

State transfers in Galera remain a mystery to most people.  Incremental State transfers (as opposed to full State Snapshot transfers) are used under the following conditions:

  • The Joiner node reports Galera a valid Galera GTID to the cluster
  • The Donor node selected contains all the transactions the Joiner needs to catch up to the rest of the cluster in its Gcache
  • The Donor node can establish a TCP connection to the Joiner on port 4568 (by default)

IST states

Galera has …

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Become a MySQL DBA blog series - Live Migration using MySQL Replication
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Migrating your database to a new datacenter can be a high-risk and time-consuming process. A database contains state, and can be much harder to migrate as compared to web servers, queues or cache servers. 

In this blog post, we will give you some tips on how to migrate your data from one service provider to another. The process is somewhat similar to our previous post on how to upgrade MySQL, but there are a couple of important differences. 
This is the seventh installment in the …

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In search of cleanliness : the elusive silent installation
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A clean installation of a database server is one where everything goes according to the expectations. It used to be easy: you only had to do what the manual says, and, presto! you would see your database server installed and ready to use. If something went wrong, you got one or more error messages that informed you of what needs to be fixed.

Sometimes, rarely, it happened that you got also a warning message, telling you that while the installation was successful, you could improve it by fine tuning this and that. No big deal.

Gone are those times. A clean installation nowadays is a much harder exercise, …

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VividCortex Live Demo
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Have you been considering VividCortex but putting off a free trial? Are you a user who wants to get the most of the product? Are you a huge fan who simply wants to hear the brains behind the product give you the inside scoop?

Join us on Tuesday, September 15 at 2 p.m. ET (6 p.m. GMT), for a live walk through of VividCortex on production systems from our CEO, Baron Schwartz. He will use the product to demonstrate the following:

  • Using our top queries feature to quickly find queries that need attention
  • Finding and diagnosing stalls with …
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MYSQL_HISTFILE and .mysql_history
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The MySQL manual says:
"mysql Logging
On Unix, the mysql client logs statements executed interactively to a history file. By default, this file is named .mysql_history in your home directory. To specify a different file, set the value of the MYSQL_HISTFILE environment variable."
The trouble with that is: it doesn't tell you what you don't need to know. So I'll tell you.


The history-file concept that MySQL and MariaDB are following is indeed "on Unix" and specifically is like the …

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Is mysql/innodb good for high volume inserts?
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As we are collecting an ever increasing amount of data and analyzing it, data storage products with alternate file structures have become popular, such as LSMs (log structured merge files) which is implemented in Cassandra and Hbase, as well as fractal indexes found in TokuDB/MX, which is an alternate file structure plugin for mysql and [...]

Inspecting All The Metrics With VividCortex
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Someone asked me the other day about some of the more obscure metrics available from a database server’s internals, and wanted access to those. As it happens, we have a feature that lets you see every metric on your systems—yes, every metric, which is typically many thousands, sometimes millions.

First, though, let’s look at what this user was examining. We ship VividCortex with a prebuilt set of templates for graphing popular systems, to reduce time-to-insight as much as possible. (No more Google searching for good graph templates and fighting to get them installed!) They look like this:

There’s quite a variety of templates, dozens for …

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MySQL 5.6 to 5.7 Upgrade Warning
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The MySQL 5.7.8 Release Candidate was released August 3rd. But before you upgrade, be sure to read how to upgrade from 5.6 to 5.7 PLEASE.

Yes, you need to make a backup (or three or four).

Be sure to run mysql_upgrade after starting the 5.7 binary. There are some changes to tables that must be made and this is the way to do it.

The …

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Quickly tell who is writing to a MySQL replica
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Many of us have been there in the past, you get an alert telling you that replication has stopped because of an error, you dig in to it to find that you’re getting an error for an update event that is trying to update a non-existent row, or a duplicate key error because the row ID for some INSERT already exists.

Even with the server set to read only (and not using the new super_read_only variable from MySQL 5.7.8), these problems can still happen – how many of you have seen over-zealous ops trying to “quickly …

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NDB 7.4 & SYS schema: When getting locks, detecting the guilty SQL &
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Here’s a way to detect the sql query causing a lock or a session to fail, and also to identify the if need be (btw, no rocket science). “a” way.. I’m sure there are many others, so feel free to suggest, please.

So, we’re using MCM, and have created a MySQL Cluster like mentioned in the cluster intro session (in Spanish I’m afraid), using 7.4.6, which comes with 5.6.24.

With the env up and running, set up a schema, some data and run a few queries:

mysql> create database …
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Showing entries 1 to 10 of 34766 10 Older Entries

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