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Displaying posts with tag: Group Replication (reset)
MySQL InnoDB Cluster with 2 Data Centers for Disaster Recovery: howto

As you know, MySQL InnoDB Cluster is a High Availability solution for MySQL. However more and more people are trying to use it as a Disaster Recovery solution with 2 data centers. Natively, this is not yet supported. But it’s already possible to realize such setup if we agree with the following points:

  •  a human interaction is required in case of Disaster Recovery which, by my own experience, is often acceptable
  • a human interaction is required if the any Primary-Master acting as asynchronous slave leaves its group  (crash, network problem, …) or becomes secondary

These are not big constraints and it’s relatively easily to deal with them.

The Architecture

The situation is as follow:

  • 2 data centers (one active, one inactive, only used for disaster recovery)
  • 2 MySQL InnoDB Clusters (one in each DC)
  • 3 members in each …
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How to Quickly Add a Node to an InnoDB Cluster or Group Replication

Quickly Add a Node to an InnoDB Cluster or Group Replication (Shutterstock)

In this blog, we’ll look at how to quickly add a node to an InnoDB Cluster or Group Replication using Percona XtraBackup.

Adding nodes to a Group Replication cluster can be easy (documented here), but it only works if the existing nodes have retained all the binary logs since the creation of the cluster. Obviously, this is possible if you create a new cluster from scratch. The nodes rotate old logs after some time, however. Technically, if the

gtid_purged

 set is non-empty, it means you will need another method to add a new node to a cluster. You also …

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Group Replication: coping with unreliable failure detection

Failure detection is a cornerstone of distributed systems as it determines which components are working properly or not, allowing it to tackle both network and host instabilities and failures. Like many other distributed systems, Group Replication (GR) requires a majority of correctly operating group members to work properly.…

On-demand primary election

Having a server acting as a primary with multiple secondaries is the most common setup when using Group Replication. Until now though, there was no way to change the current primary member while the group was running without causing some sort of disruption.…

Setting up MySQL Group Replication with MySQL Docker images

MySQL Group Replication (GR) is a MySQL Server plugin that enables you to create elastic, highly-available, fault-tolerant replication topologies. Groups can operate in a
single-primary mode with automatic primary election, where only one server accepts updates at a time. Alternatively, groups can be deployed in multi-primary mode, where all servers can accept updates, even if they are issued concurrently.…

MySQL InnoDB Cluster: upgrade from 8.0.11 to 8.0.12

In April, I already posted an article on how to upgrade safely your MySQL InnoDB Cluster, let’s review this procedure now that MySQL 8.0.12 is out.

To upgrade all the members of a MySQL InnoDB Cluster (Group), you need to keep in mind the following points:

  • upgrade all the nodes one by one
  • always end by the Primary Master in case of Single Primary Mode
  • after upgrading the binaries don’t forget to start MySQL without starting Group Replication (group_replication_start_on_boot=0)
  • to run mysql_upgrade

Let’s see this in action on the video below:

As you could see, this is quick and easy.

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MySQL InnoDB Cluster 8.0.12 – avoid old reads on partitioned members

We received feedback about how a member should act when leaving the group. And the majority of users wanted that when a node drops out of the group, it should kill all connections and shutdown. I totally agree with that behavior and it’s now the default in MySQL 8.0.12.

This new feature is explained in WL#11568.

Before this change, the server goes into super read only mode when dropping out of the group and allows users connected to this server or new connections (if you don’t use the router) to read old data.

Let’s check this out in the following video:

So now in MySQL 8.0.12, there is a mnew option called …

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Question about Semi-Synchronous Replication: the Answer with All the Details

I was recently asked a question by mail about MySQL Lossless Semi-Synchronous Replication. As I think the answer could benefit many people, I am answering it in a blog post. The answer brings us to the internals of transaction committing, of semi-synchronous replication, of MySQL (server) crash recovery, and of storage engine (InnoDB) crash recovery. I am also debunking some misconceptions that I have often seen and heard repeated by many. Let’s start by stating one of those misconceptions.

One of those misconceptions is the following (this is NOT true): semi-synchronous enabled slaves are always the most up-to-date slaves (again, this is NOT true). If you hear it yourself, then please call people out on it to avoid this spreading more. Even if some slaves have semi-synchronous replication disabled (I will use semi-sync for …

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MySQL at Oracle Open World and Oracle Code One Oct 22-25 2018 !

This year again, the MySQL Team is eager to participate in the Oracle Open World conference. This is a great opportunity for our engineers and the entire MySQL Team to highlight what we’ve done, and also what we are working on. Another reason to be excited this year is our new participation to Code One, the Oracle developer focused conference. Oracle Code One will include a full track dedicated to MySQL.

This is very good news for everybody attending, from DBAs to developers, as we will offer even more great content ! This year, in both events, we will highlight how NoSQL+SQL=MySQL.

Our MySQL Engineers will deliver fantastic sessions about …

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MySQL Router HA with Keepalived

After having explained how to achieve HA for MySQL Router for people who doesn’t want to install the MySQL Router on the application servers and after having illustrated how to use Pacemaker, this article explains how to setup HA for MySQL Router using keepalived.

Keepalived is very popular, maybe because it’s also very easy to use. We can of course use 2 or more servers. The principle is the same as on the previous articles, if the router dies, the virtual IP used by the application server(s) to connect to MySQL is sent to another machine where mysqlrouter is still running.

Let’s have a look at the configuration, in this case we use 2 machines, mysql1 and …

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