In a MySQL 5.7 master-slave setup that uses the default semisynchronous replication setting for rpl_semi_sync_master_wait_point, a crash of the master and failover to the slave is considered to be lossless. However, when the crashed master comes back, you may find that it has transactions that are not present in the current master (which was previously a slave). This behavior may be puzzling, given that semisynchronous replication is supposed to be lossless, but this is actually an expected behavior in MySQL. Why exactly this happens is explained in full detail in the …[Read more]
Over the past few days we have been working with a number of customers on the best way to handle Triggers within their MySQL environment when combined with Tungsten Replicator. We looked at situations where Tungsten Replicator was either part of a Tungsten Clustering installation or a standalone replication pipeline.
This blog dives head first into the minefield of Triggers and Replication.
Summary and Recommendations
The conclusion was that there is no easy one-answer-fits-all solution – It really depends on the complexity of your environment and the amount of flexibility you have in being able to adjust. Our top level summary and recommendations are as follows:
If using Tungsten Clustering and you need to use Triggers:
- Switch to …
The latest MySQL 8.0 release is out. That is MySQL 8.0.18. We have some new replication enhancements and some work done on replication internals in this release that we would like to highlight and celebrate with our users. Here is a quick summary.…
For optimal compatibility and performance, all members of a group should run the same version of MySQL Server and therefore of Group Replication. However, in some situations, it may be required to that a group contains servers running different versions. For example, during a rolling upgrade.…
MySQL 8.0.17 is out. In addition to fixing a few bugs here and there, we also have a couple of new replication features that I would like to present. Thence, allow me to give you a quick summary. As usual, there shall be follow-up blog posts providing details, so stay tuned.…
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Background The Skinny
Performing schema changes often requires extended downtime for
applications. This is due to MySQL needing to rebuild tables for
common schema change operations. Tools like
pt-online-schema-change have been written to try to
overcome the downtime associated with schema changes, however
they are complex and put a high load on the database. Amazon’s
Aurora improves some schema changes operations, but still
requires a table rebuild for common operations like adding a
after, or simply
to add a column with a
default value. Rebuilding a
table with millions of rows can take hours and prevent writes to
that table the entire time.
How Can Tungsten Clustering Keep Applications Running? How Does It All Work?
MySQL 8.0.16 has been released last Thursday. In it, you can find some new replication features. Here is a quick summary. Follow-up blog posts will provide details about these features.
- Large Messages Fragmentation Layer for Group Replication. Tiago Vale’s work, introduces message fragmentation to the Group Communication Framework.
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MySQL InnoDB Cluster was introduced in MySQL version 5.7 and consists of three parts – Group Replication, MySQL Shell and MySQL Router. MySQL InnoDB Cluster provides a complete high availability solution for MySQL. In this post, I am going to explain how to setup a three-node cluster using the MySQL Shell.
|Note: Visit this page to learn more about …|
You say you want a Replication?
One of the best features of MySQL is the ability to use MySQL‘s built-in database replication feature to automatically replicate data from one server (source/master) to another (slave/replica). Group Replication was added in MySQL 5.7 as a way to provide a high-availability solution using a new variation of MySQL replication.
(In some earlier posts, I explained how to setup Group Replication using three MySQL database servers and how to …[Read more]
MariaDB OpenWorks happened February 25 – 27, 2019 in New York City. It was filled with plenty of activity.
The keynote by Michael Howard, C.E.O. of MariaDB, is an interesting watch, one with many quoted articles especially around “strip-mining open-source technologies and companies,” and “abusing the license and privilege, and not giving back to the community.” Many articles were written about this topic, and it’s clear that open-source has arrived considering all of the success around the IBM acquisition of Red Hat, the Elastic I.P.O., the Microsoft acquisition of GitHub, the SalesForce acquisition fo MuleSoft and the MongoDB I.P.O.
Seppo Jaakola, the C.E.O. of Codership, talked about …[Read more]