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MySQL Group Replication – Monitoring
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Multi-master update everywhere solution for MySQL is here. MySQL Group Replication ensures virtual synchronous updates on any node in a group of MySQL servers, with conflict handling and failure detection. Distributed recovery is also in the package to ease the process of adding new nodes.

Starting with MySQL 5.7.2 there has been a constant effort from the replication team to provide more fields to monitor the replication performance in the performance schema tables. This post gives a brief  overview of the Performance Schema tables that have been introduced for MySQL Group Replication.

TABLES INTRODUCED

There are …

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WAIT_FOR_EXECUTED_GTID_SET for MySQL Replication
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With the introduction of Global Transaction Identifiers(GTID) in MySQL from mysql-5.6 GA a whole lot of different functionality have been developed around it so that GTID could be used in a much simpler and efficient way.

One of the interesting functionality with GTID in use is the function to sync a slave with its
master server using the WAIT_UNTIL_SQL_THREAD_AFTER_GTIDS. This is used to do a timed or an indefinite wait till the servers in contention are in sync with respect to the GTID executed set.

This function is used to address specific use cases in which transactions are applied using SQL/worker thread. In order to …


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Preserve Master’s Commit Order on Slave
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On MySQL-5.7.2, we released a new type of multi-threaded slave (MTS). It is called logical clock based MTS. Because it can parallel apply transactions in the same schema, it has the potential to improve slave throughput on almost any application, regardless of the schema layout. After it was released, we continued to work on the framework to improve it further. Therefore, 5.7.5 includes a few enhancements, in addition to those released as part of previous DMRs. This blog post introduces one of the new features in the latest DMR.

slave_preserve_commit_order

It is a system global variable and can be set dynamically.

  • SET GLOBAL …
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Transaction Retry Is Available On Multi-Threaded Slave
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 I am happy to announce that slave_transaction_retries is available on multi-threaded slave now. You will no longer see the warning that slave_transaction_retries is not supported by multi-threaded slave since MySQL-5.7.5.

Multi-threaded slave and single-threaded slave share the system variable slave_transaction_retries and they have similar transaction retry logic. So this blog just brings you a little new knowledge and then refresh you with the transaction retry logic.

Transaction Retry In Worker Threads

For multi-threaded slave, Transaction retry is done in worker threads when they are applying their …

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Getting started with MySQL Group Replication
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The multi master plugin for MySQL is here. MySQL Group Replication ensures virtual synchronous updates on any node in a group of MySQL servers, with conflict handling and failure detection. Distributed recovery is also in the package to ease the process of adding new nodes to your server group.

How do you start? Just sit back, download MySQL Group Replication from http://labs.mysql.com/ and then let us begin this journey into the world of multi master MySQL.

Pre requisites

Under its hood, the multi master plugin is powered by a group communication toolkit. This is what …

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MySQL Group Replication: A small Corosync guide
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MySQL Group Replication is here and with it comes the need to install and configure the underlying group communication toolkit that supports it: Corosync. Corosync is a well known and reliable Group Communication System that is used in such applications as Pacemaker.

In term of support, we develop MySQL Group Replication based on Corosync version 1.4.6, so this tutorial is based on this version. Regardless of this, no known problems are know to exists when using newer versions, but no extensive testing has been done on those.

Along with Corosync we also encourage the use of NSS to better secure your data that is transmitted in the …

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MySQL Group Replication: Distributed Recovery behind the scenes
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The new addition to the MySQL planet, MySQL Group Replication is now on Labs Release for you to try it! It offers you update everywhere capabilities on any group of normal, out of the box, MySQL servers. Concurrent updates on a setup of several MySQL servers is now possible and this with our trademark: the ease of use.

In fact we ship MySQL Group Replication in such a way that for you to form a group and add new nodes, all that is needed is to configure the servers with your unique group id and just press start. In this post we show you the “behind the scenes” of this process, on how the node catches up with the remaining servers through …

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Group communication behind the scenes
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Introduction

The multi master plugin for MySQL is here. MySQL Group Replication ensures virtually synchronous updates on any node in a group of MySQL servers, with conflict handling and failure detection. Distributed recovery is also in the package to ease the process of adding new nodes.

For a better understanding on how things work, we go under the hood in this post and you will have a better understanding about the communication layer functionality and implementation.

Group Communication concepts

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MySQL Group Replication : Hello World!
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The first preview  release of MySQL Group Replication, a MySQL plugin that brings multi-master update everywhere to MySQL, is available on labs. This plugin ties together concepts and technologies from distributed systems, such as group communication, with traditional database replication. The ultimate result is a seamlessly distributed and replicated database over a set of MySQL servers cooperating together to keep the replicated state strongly consistent.

Introduction

Before diving into the details of MySQL Group Replication, lets first introduce some background concepts and an overview of how things work. These will …

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GROUP BY fixed
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Friend and former colleague Roland Bouwman has written an excellent update on the GROUP BY implementation in MySQL.

MySQL’s implementation of GROUP BY has historically been quirky. Sometimes that quirkiness has been useful, but often it causes grief as SQL authors can make mistakes that are executed but don’t produce the results they want (or expect).

Simple example:

SELECT cat, COUNT(val) as cnt, othercol FROM tbl GROUP BY cat

The ‘cat‘ column is in the GROUP BY clause, the COUNT(val) is an …

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10 Newer Entries Showing entries 91 to 100 of 983 10 Older Entries

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