Today’s blog post is related again to MySQL Group Replication.

By default MySQL Group Replication runs in Single-Primary mode. And it’s the best option and the option you should use.

But sometimes it might happen that in very specific cases you would like to run you MGR Cluster in Multi-Primary mode: writing simultaneously on all the nodes member of the Group.

It’s of course feasible but you need to make some extra verification as not all workload are compatible with this behavior of the cluster.

Requirements

The requirements are the same as those for using MGR in Single-Primary mode:

• InnoDB Storage Engine
• Primary Keys
• IPv4 Network
• Binary Log Active
• Slave Updates Logged
• Binary …

Today in our series of articles related to MySQL Group Replication’s limitations, let’s have a quick look at Savepoints.

The manual is clear about this: Transaction savepoints are not supported.

The first thing to check then is if the application that will use our MySQL Group Replication Cluster is currently using savepoints.

We have two ways to find this, the first is using STATUS variables:

mysql> show global status like '%save%';
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| Com_release_savepoint      | 2     |
| Com_rollback_to_savepoint  | 0     |
| Com_savepoint              | 4     |
| Handler_savepoint          | 0     |
| Handler_savepoint_rollback | 0     |
+----------------------------+-------+

…

Today’s article is about the first two restrictions in the requirements page of the manual:

• InnoDB Storage Engine: data must be stored in the InnoDB transactional storage engine.
• Primary Keys: every table that is to be replicated by the group must have an explicit primary key defined.

So the first requirement is easy to check by a simple query that list all the non InnoDB tables:

SELECT table_schema, table_name, engine, table_rows, 
       (index_length+data_length)/1024/1024 AS sizeMB 
FROM information_schema.tables 
WHERE engine != 'innodb' 
  AND table_schema NOT IN 
    ('information_schema', 'mysql', 'performance_schema');

The second one is a bit more tricky. Let me show you first how Group Replication behaves:

Case 1: no keys

Let’s create a table with no …

In this article, I will show you how it’s possible to perform an online migration from a 3 members Galera cluster setup (in this case I’m using PXC 5.7.14) to a 3 members MySQL Group Replication cluster setup (MySQL Community 5.7.17).

Don’t forget that before adopting Group Replication as database backend, you should validate that your application do match GR requirements and limitations. When this is validated, you can start !

So first, let’s have a look at the current situation:

We have an application (sysbench 0.5), reading and writing to a Galera Cluster ( …

It’s a wonderful news, we have released MySQL 5.7.17 with Group Replication Plugin (GA quality).

From the definition, Group Replication is a multi-master update everywhere replication plugin for MySQL with built-in conflict detection and resolution, automatic distributed recovery, and group membership.

So we can indeed compare this solution with Galera from Codership which is a Replication Plugin implementing the WSREP API. WSREP, Write Set Replication,  extends the replication API to provide all the information and hooks required for true multi-master, “virtually synchronous” replication.

With Group Replication, MySQL implemented all this information …

Great news: Group Replication is now officially released with MySQL 5.7.17, congratulations to everybody that worked so hard for it!

In this post I plan to share more details about the performance of Group Replication while addressing one of our frequently asked questions, which is how it performs compared to Galera.…

The slides of my joint tutorial with Kenny Gryp from Percona on MySQL InnoDB Cluster and Group Replication are now online.

We got nice questions during the session and very good feedback.

MySQL Group Replicatio in a nutshell – MySQL InnoDB Cluster from Frédéric Descamps

We are very excited about the next release of MySQL Group Replication 0.9.0 in MySQL 5.7.15 and the great work that has been done to improve its stability. Release after release, MySQL Group Replication becomes more stable and more user-friendly and has reached a maturity level that made us declare 0.9.0 a release candidate.…

A new Group Replication plugin labs release has came out, a little over a week ago. Exciting news! This shows that the team has been working hard to shape up the plugin so that it meets the required feature set, performance and quality standards to be released as GA.…

MySQL is a growing presence at Oracle Open World. While most of the headlines belong to the main products, where Oracle services are aiming at world domination, MySQL shared the spotlight, as it was announced to be part of Oracle database cloud. It seems a logical move for Oracle: after all the effort to make MySQL 5.7 the biggest release ever, it stands to reason that it is offered as a competitive feature in its own database as a service.

With this offer, Oracle is applying enterprise pricing and methodologies to a target of emerging companies. MySQL in the Oracle cloud differs from the competition by a few key points:

• It's only MySQL 5.7. While this is the most advanced MySQL server …