Replication enables data from one MySQL server to be replicated on one or more other MySQL servers. Replication is mostly used as scale-out solution. In such a solution, all writes and updates take place on the master server, while reads take place on one or more slaves. This model is actually known as master-slave replication and this is the kind of replication that I will be setting up in this post.
If you follow Giuseppe Maxia's Datacharmer
blog you have seen several recent articles on Tungsten Replicator. Giuseppe and I work
closely together on replication at Continuent, and I have
promised a matching set of articles about replication internals
that match the practical introduction provided by Giuseppe.
In this first article I will describe replication
services, which are message processing flows that run in the
Tungsten Replicator.
Unlike many replication engines, Tungsten Replicator can run
multiple replication services concurrently. There is a
central management interface that allows you to start new
replication services without disturbing services that are already
running. Each replication service also has its own
management interface so that …
After part I: the basics, and part II: parallel apply, we deal now with some
more mundane topic, or how to deploy replication services in a
way that they fit our business, covering from the basic
master/slave to the most advanced multi-source scheme.
Master/slaveThe most common topology is master/slave. One master,
many slaves. This topology is equivalent to MySQL native
replication. The differences are in the additional features.
Tungsten supports seamless failover and parallel replication in
all topologies.
Figure 1. Tungsten master/slave replication
Unlike MySQL, and unlike previous versions of Tungsten, the
implementation of this topology uses a dedicated service for the …
I hope you liked the first part of this series of lessons. And
I really hope that you have followed the instructions and got
your little replication cluster up and working. |
If you haven't done that, thinking that you would spare your
energies for more juicy matters, I have news for you. What I
explained in the previous part is exactly what you need to do to
set up parallel replication. With just a tiny additional
detail.
For the sake of the diligent readers who have followed the
instructions with the first lessons, I won't repeat them, but
I'll invite you to set the environment as explained in the first
part.
Once you have a cluster up and …
These are exciting times for the Drizzle team. We just released our first RC and things are finally coming together into some awesome new features. I’m excited to bring you latest news from the replication front:
Where to begin? Well, many moons ago, Brian sent David Shrewsbury and myself out on the task of making the transaction_log plugin rock solid. This plugin provides a file-based log that captures the server’s state via protobuf messages. After much blood, sweat, and tears (and *many* bugs), we accomplished our task with *plenty* of help from …
[Read more]I am pleased to announce the availability of the MariaDB 5.2 feature preview release. Find the details and download links on the knowledgebase.
There has been quite good interest in the replication work I have been doing around MariaDB, and I wanted a way to make it easy for people to use, experiment with, and give feedback on the new features. The result is this replication feature preview release. This will all eventually make it into the next official release, however this is likely still some month off.
All the usual binary packages and source tarballs are available for download. As something new, I now also made apt-enabled repositories available for Debian and Ubuntu; this should greatly simplify installation on these .deb based …
[Read more]Overview MySQL Replication is one of the most used and valued features of the MySQL Server. Unlike some other products on the market, it’s out-of-the-box, easy to configure, non-paid and smart features. Most of our medium/large/super-large installation base are using replication to achieve “scale-out” scaling. Some will use it for backup purposes (not as HA [...]
MySQL DBAs and developers: oil your fingers and get ready to
experience a new dimension of data replication. I am pleased
to announce that Continuent has just released Tungsten Replicator 2.0, an open source
data replication engine that can replace MySQL native
replication with a set of advanced features. A note about the source code. The current version of Tungsten Replicator available in the web site is free to use, but it is not yet the open source version. We need a few weeks more to extract the code from the enterprise tree and make a new build. But we did not want to delay the user experience. So everything … |
Sometimes you know for sure. And sometimes you wonder: Is this
server part of a replication system? And, most specifically, is
it an active slave?
The completeness of the answer depends on how much visibility you
have on the server.
If you can ask the DBA, and possibly have access to the server
data directory and configuration file, you can get a satisfactory
answer. But if your access is limited to SQL access, things get a
bit more complicated.
If you have the SUPER or REPLICATION_CLIENT privilege, then it's
easy, at least in the surface.
SHOW SLAVE STATUS will tell you if the slave is running. An empty
set means that the server was not configured as a slave.
The answer is not absolute, though. You need to read the output
of SHOW SLAVE STATUS to understand if replication is under
way.
For example, what is the difference between these two
listings?
## listing 1 …
[Read more]
Many early startups that use a single server for all services or a single database server for their website talk about how they would like to achieve higher availability with MySQL. This is not possible without at least two database servers. Using MySQL replication you can then support higher availability in several varying capacities. An additional MySQL database server can satisfy several infrastructure needs including:
- A primary hot backup
- A datasource for performing backups
- Read scalability infrastructure
- A reporting server
- A benchmarking server
- A fail-over/fail back master environment
MySQL replication is very easy to configure and deploy, a task that takes < 30 minutes for an experienced MySQL DBA. However, altering your backup and recovery strategy, modifying your application to support read/write splitting or implementing a fail-over/fail back …
[Read more]